Merge branch 'rust_extras' into next

map fields with values of message type were not serialized correctly

.github/workflows/ci.yml

@@ -13,17 +13,15 @@ jobs:
     name: ${{ matrix.os }} / ${{ matrix.python-version }}
     runs-on: ${{ matrix.os }}-latest
     strategy:
+      fail-fast: false
       matrix:
         os: [Ubuntu, MacOS, Windows]
-        python-version: [3.6, 3.7, 3.8, 3.9]
-        exclude:
-          - os: Windows
-            python-version: 3.6
+        python-version: ['3.7', '3.8', '3.9', '3.10', '3.11']
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
 
@@ -43,7 +41,7 @@ jobs:
         run: poetry config virtualenvs.in-project true
 
       - name: Set up cache
-        uses: actions/cache@v2
+        uses: actions/cache@v3
         id: cache
         with:
           path: .venv
@@ -56,9 +54,7 @@ jobs:
 
       - name: Install dependencies
         shell: bash
-        run: |
-          poetry run python -m pip install pip -U
-          poetry install
+        run: poetry install -E compiler
 
       - name: Generate code from proto files
         shell: bash
@@ -66,4 +62,4 @@ jobs:
 
       - name: Execute test suite
         shell: bash
-        run: poetry run pytest tests/
+        run: poetry run python -m pytest tests/

.github/workflows/code-quality.yml

@@ -13,14 +13,6 @@ jobs:
     name: Check code/doc formatting
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v2
-    - name: Run Black
-      uses: lgeiger/black-action@master
-      with:
-        args: --check src/ tests/ benchmarks/
-
-    - name: Install rST dependcies
-      run: python -m pip install doc8
-    - name: Lint documentation for errors
-      run: python -m doc8 docs --max-line-length 88 --ignore-path-errors "docs/migrating.rst;D001"
-      # it has a table which is longer than 88 characters long
+    - uses: actions/checkout@v3
+    - uses: actions/setup-python@v4
+    - uses: pre-commit/action@v2.0.3

.github/workflows/release.yml

@@ -15,9 +15,9 @@ jobs:
     name: Distribution
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Set up Python 3.8
-        uses: actions/setup-python@v2
+        uses: actions/setup-python@v4
         with:
           python-version: 3.8
       - name: Install poetry

.gitignore

@@ -17,3 +17,4 @@ output
 .venv
 .asv
 venv
+.devcontainer

.pre-commit-config.yaml

@@ -0,0 +1,21 @@
+ci:
+  autofix_prs: false
+
+repos:
+  - repo: https://github.com/pycqa/isort
+    rev: 5.11.5
+    hooks:
+      - id: isort
+
+  - repo: https://github.com/psf/black
+    rev: 23.1.0
+    hooks:
+      - id: black
+        args: ["--target-version", "py310"]
+
+  - repo: https://github.com/PyCQA/doc8
+    rev: 0.10.1
+    hooks:
+    -   id: doc8
+        additional_dependencies:
+          - toml

CHANGELOG.md

@@ -7,6 +7,108 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Versions suffixed with `b*` are in `beta` and can be installed with `pip install --pre betterproto`.
 
+## [2.0.0b6] - 2023-06-25
+
+- **Breaking**: the minimum Python version has been bumped to `3.7` [#444](https://github.com/danielgtaylor/python-betterproto/pull/444)
+
+- Support generating [Pydantic dataclasses](https://docs.pydantic.dev/latest/usage/dataclasses). 
+  Pydantic dataclasses are are drop-in replacement for dataclasses in the standard library that additionally supports validation.
+  Pass `--python_betterproto_opt=pydantic_dataclasses` to enable this feature.
+  Refer to [#406](https://github.com/danielgtaylor/python-betterproto/pull/406)
+  and [README.md](https://github.com/danielgtaylor/python-betterproto#generating-pydantic-models) for more information.
+  
+- Added support for `@generated` marker [#382](https://github.com/danielgtaylor/python-betterproto/pull/382)
+- Pull down the `include_default_values` argument to `to_json()` [#405](https://github.com/danielgtaylor/python-betterproto/pull/405)
+- Pythonize input_type name in py_input_message [#436](https://github.com/danielgtaylor/python-betterproto/pull/436)
+- Widen `from_dict()` to accept any `Mapping` [#451](https://github.com/danielgtaylor/python-betterproto/pull/451)
+- Replace `pkg_resources` with `importlib` [#462](https://github.com/danielgtaylor/python-betterproto/pull/462)
+  
+- Fix typechecker compatiblity checks in server streaming methods [#413](https://github.com/danielgtaylor/python-betterproto/pull/413)
+- Fix "empty-valued" repeated fields not being serialised [#417](https://github.com/danielgtaylor/python-betterproto/pull/417)
+- Fix `dict` encoding for timezone-aware `datetimes` [#468](https://github.com/danielgtaylor/python-betterproto/pull/468)
+- Fix `to_pydict()` serialization for optional fields [#495](https://github.com/danielgtaylor/python-betterproto/pull/495)
+- Handle empty value objects properly [#481](https://github.com/danielgtaylor/python-betterproto/pull/481)
+  
+## [2.0.0b5] - 2022-08-01
+
+- **Breaking**: Client and Service Stubs no longer pack and unpack the input message fields as parameters [#331](https://github.com/danielgtaylor/python-betterproto/pull/311)
+
+    Update your client calls and server handlers as follows:
+
+    Clients before:
+
+    ```py
+    response = await service.echo(value="hello", extra_times=1)
+    ```
+
+    Clients after:
+
+    ```py
+    response = await service.echo(EchoRequest(value="hello", extra_times=1))
+    ```
+
+    Servers before:
+
+    ```py
+    async def echo(self, value: str, extra_times: int) -> EchoResponse: ...
+    ```
+
+    Servers after:
+
+    ```py
+    async def echo(self, echo_request: EchoRequest) -> EchoResponse:
+        # Use echo_request.value
+        # Use echo_request.extra_times
+        ...
+    ```
+
+- Add `to/from_pydict()` for `Message` [#203](https://github.com/danielgtaylor/python-betterproto/pull/203)
+- Format field comments also as docstrings [#304](https://github.com/danielgtaylor/python-betterproto/pull/304)
+- Implement `__deepcopy__` for `Message` [#339](https://github.com/danielgtaylor/python-betterproto/pull/339)
+- Run isort on compiled code [#355](https://github.com/danielgtaylor/python-betterproto/pull/355)
+- Expose timeout, deadline and metadata parameters from grpclib [#352](https://github.com/danielgtaylor/python-betterproto/pull/352)
+- Make `Message.__getattribute__` invisible to type checkers [#359](https://github.com/danielgtaylor/python-betterproto/pull/359)
+
+- Fix map field edge-case [#254](https://github.com/danielgtaylor/python-betterproto/pull/254)
+- Fix message text in `NotImplementedError` [#325](https://github.com/danielgtaylor/python-betterproto/pull/325)
+- Fix `Message.from_dict()` in the presence of optional datetime fields [#329](https://github.com/danielgtaylor/python-betterproto/pull/329)
+- Support Jinja2 3.0 to prevent version conflicts [#330](https://github.com/danielgtaylor/python-betterproto/pull/330)
+- Fix overwriting top level `__init__.py` [#337](https://github.com/danielgtaylor/python-betterproto/pull/337)
+- Remove deprecation warnings when fields are initialised with non-default values [#348](https://github.com/danielgtaylor/python-betterproto/pull/348)
+- Ensure nested class names are converted to PascalCase [#353](https://github.com/danielgtaylor/python-betterproto/pull/353)
+- Fix `Message.to_dict()` mutating the underlying Message [#378](https://github.com/danielgtaylor/python-betterproto/pull/378)
+- Fix some parameters being missing from services [#381](https://github.com/danielgtaylor/python-betterproto/pull/381)
+
+## [2.0.0b4] - 2022-01-03
+
+- **Breaking**: the minimum Python version has been bumped to `3.6.2`
+
+- Always add `AsyncIterator` to imports if there are services [#264](https://github.com/danielgtaylor/python-betterproto/pull/264)
+- Allow parsing of messages from `ByteStrings` [#266](https://github.com/danielgtaylor/python-betterproto/pull/266)
+- Add support for proto3 optional [#281](https://github.com/danielgtaylor/python-betterproto/pull/281)
+
+- Fix compilation of fields with names identical to builtin types [#294](https://github.com/danielgtaylor/python-betterproto/pull/294)
+- Fix default values for enum service args [#299](https://github.com/danielgtaylor/python-betterproto/pull/299)
+
+## [2.0.0b3] - 2021-04-07
+
+- Generate grpclib service stubs [#170](https://github.com/danielgtaylor/python-betterproto/pull/170)
+- Add \_\_version\_\_ attribute to package [#134](https://github.com/danielgtaylor/python-betterproto/pull/134)
+- Use betterproto generated messages in the plugin [#161](https://github.com/danielgtaylor/python-betterproto/pull/161)
+- Sort the list of sources in generated file headers [#164](https://github.com/danielgtaylor/python-betterproto/pull/164)
+- Micro-optimization: use tuples instead of lists for conditions [#228](https://github.com/danielgtaylor/python-betterproto/pull/228)
+- Improve datestring parsing [#213](https://github.com/danielgtaylor/python-betterproto/pull/213)
+
+- Fix serialization of repeated fields with empty messages [#180](https://github.com/danielgtaylor/python-betterproto/pull/180)
+- Fix compilation of fields named 'bytes' or 'str' [#226](https://github.com/danielgtaylor/python-betterproto/pull/226)
+- Fix json serialization of infinite and nan floats/doubles [#215](https://github.com/danielgtaylor/python-betterproto/pull/215)
+- Fix template bug resulting in empty \_\_post_init\_\_ methods [#162](https://github.com/danielgtaylor/python-betterproto/pull/162)
+- Fix serialization of zero-value messages in a oneof group [#176](https://github.com/danielgtaylor/python-betterproto/pull/176)
+- Fix missing typing and datetime imports [#183](https://github.com/danielgtaylor/python-betterproto/pull/183)
+- Fix code generation for empty services [#222](https://github.com/danielgtaylor/python-betterproto/pull/222)
+- Fix Message.to_dict and from_dict handling of repeated timestamps and durations [#211](https://github.com/danielgtaylor/python-betterproto/pull/211)
+- Fix incorrect routes in generated client when service is not in a package [#177](https://github.com/danielgtaylor/python-betterproto/pull/177)
+
 ## [2.0.0b2] - 2020-11-24
 
 - Add support for deprecated message and fields [#126](https://github.com/danielgtaylor/python-betterproto/pull/126)
@@ -35,7 +137,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [2.0.0b1] - 2020-07-04
 
-[Upgrade Guide](./docs/upgrading.md) 
+[Upgrade Guide](./docs/upgrading.md)
 
 > Several bugfixes and improvements required or will require small breaking changes, necessitating a new version.
 > `2.0.0` will be released once the interface is stable.

LICENSE.md

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Daniel G. Taylor
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -1,18 +1,20 @@
 # Better Protobuf / gRPC Support for Python
 
 ![](https://github.com/danielgtaylor/python-betterproto/workflows/CI/badge.svg)
+> :octocat: If you're reading this on github, please be aware that it might mention unreleased features! See the latest released README on [pypi](https://pypi.org/project/betterproto/).
 
 This project aims to provide an improved experience when using Protobuf / gRPC in a modern Python environment by making use of modern language features and generating readable, understandable, idiomatic Python code. It will not support legacy features or environments (e.g. Protobuf 2). The following are supported:
 
 - Protobuf 3 & gRPC code generation
   - Both binary & JSON serialization is built-in
-- Python 3.6+ making use of:
+- Python 3.7+ making use of:
   - Enums
   - Dataclasses
   - `async`/`await`
   - Timezone-aware `datetime` and `timedelta` objects
   - Relative imports
   - Mypy type checking
+- [Pydantic Models](https://docs.pydantic.dev/) generation (see #generating-pydantic-models)
 
 This project is heavily inspired by, and borrows functionality from:
 
@@ -37,6 +39,8 @@ This project exists because I am unhappy with the state of the official Google p
   - Uses `SerializeToString()` rather than the built-in `__bytes__()`
   - Special wrapped types don't use Python's `None`
   - Timestamp/duration types don't use Python's built-in `datetime` module
+
+
 This project is a reimplementation from the ground up focused on idiomatic modern Python to help fix some of the above. While it may not be a 1:1 drop-in replacement due to changed method names and call patterns, the wire format is identical.
 
 ## Installation
@@ -57,7 +61,7 @@ pip install betterproto
 
 ### Compiling proto files
 
-Now, given you installed the compiler and have a proto file, e.g `example.proto`:
+Given you installed the compiler and have a proto file, e.g `example.proto`:
 
 ```protobuf
 syntax = "proto3";
@@ -159,6 +163,12 @@ service Echo {
 }
 ```
 
+Generate echo proto file:
+
+```
+python -m grpc_tools.protoc -I . --python_betterproto_out=. echo.proto
+```
+
 A client can be implemented as follows:
 ```python
 import asyncio
@@ -170,10 +180,10 @@ from grpclib.client import Channel
 async def main():
     channel = Channel(host="127.0.0.1", port=50051)
     service = echo.EchoStub(channel)
-    response = await service.echo(value="hello", extra_times=1)
+    response = await service.echo(echo.EchoRequest(value="hello", extra_times=1))
     print(response)
 
-    async for response in service.echo_stream(value="hello", extra_times=1):
+    async for response in service.echo_stream(echo.EchoRequest(value="hello", extra_times=1)):
         print(response)
 
     # don't forget to close the channel when done!
@@ -185,6 +195,7 @@ if __name__ == "__main__":
     loop.run_until_complete(main())
 
 ```
+
 which would output
 ```python
 EchoResponse(values=['hello', 'hello'])
@@ -192,6 +203,37 @@ EchoStreamResponse(value='hello')
 EchoStreamResponse(value='hello')
 ```
 
+This project also produces server-facing stubs that can be used to implement a Python
+gRPC server.
+To use them, simply subclass the base class in the generated files and override the
+service methods:
+
+```python
+import asyncio
+from echo import EchoBase, EchoRequest, EchoResponse, EchoStreamResponse
+from grpclib.server import Server
+from typing import AsyncIterator
+
+
+class EchoService(EchoBase):
+    async def echo(self, echo_request: "EchoRequest") -> "EchoResponse":
+        return EchoResponse([echo_request.value for _ in range(echo_request.extra_times)])
+
+    async def echo_stream(self, echo_request: "EchoRequest") -> AsyncIterator["EchoStreamResponse"]:
+        for _ in range(echo_request.extra_times):
+            yield EchoStreamResponse(echo_request.value)
+
+
+async def main():
+    server = Server([EchoService()])
+    await server.start("127.0.0.1", 50051)
+    await server.wait_closed()
+
+if __name__ == '__main__':
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(main())
+```
+
 ### JSON
 
 Both serializing and parsing are supported to/from JSON and Python dictionaries using the following methods:
@@ -323,6 +365,25 @@ datetime.datetime(2019, 1, 1, 11, 59, 58, 800000, tzinfo=datetime.timezone.utc)
 {'ts': '2019-01-01T12:00:00Z', 'duration': '1.200s'}
 ```
 
+## Generating Pydantic Models
+
+You can use python-betterproto to generate pydantic based models, using
+pydantic dataclasses. This means the results of the protobuf unmarshalling will
+be typed checked. The usage is the same, but you need to add a custom option
+when calling the protobuf compiler:
+
+
+```
+protoc -I . --python_betterproto_opt=pydantic_dataclasses --python_betterproto_out=lib example.proto
+```
+
+With the important change being `--python_betterproto_opt=pydantic_dataclasses`. This will
+swap the dataclass implementation from the builtin python dataclass to the
+pydantic dataclass. You must have pydantic as a dependency in your project for
+this to work.
+
+
+
 ## Development
 
 - _Join us on [Slack](https://join.slack.com/t/betterproto/shared_invite/zt-f0n0uolx-iN8gBNrkPxtKHTLpG3o1OQ)!_
@@ -330,7 +391,7 @@ datetime.datetime(2019, 1, 1, 11, 59, 58, 800000, tzinfo=datetime.timezone.utc)
 
 ### Requirements
 
-- Python (3.6 or higher)
+- Python (3.7 or higher)
 
 - [poetry](https://python-poetry.org/docs/#installation)
   *Needed to install dependencies in a virtual environment*
@@ -343,8 +404,7 @@ datetime.datetime(2019, 1, 1, 11, 59, 58, 800000, tzinfo=datetime.timezone.utc)
 
 ```sh
 # Get set up with the virtual env & dependencies
-poetry run pip install --upgrade pip
-poetry install
+poetry install -E compiler
 
 # Activate the poetry environment
 poetry shell
@@ -379,7 +439,7 @@ Adding a standard test case is easy.
 
 It will be picked up automatically when you run the tests.
 
-- See also: [Standard Tests Development Guide](betterproto/tests/README.md)
+- See also: [Standard Tests Development Guide](tests/README.md)
 
 #### Custom tests
 
@@ -404,18 +464,18 @@ poe full-test
 
 ### (Re)compiling Google Well-known Types
 
-Betterproto includes compiled versions for Google's well-known types at [betterproto/lib/google](betterproto/lib/google).
+Betterproto includes compiled versions for Google's well-known types at [src/betterproto/lib/google](src/betterproto/lib/google).
 Be sure to regenerate these files when modifying the plugin output format, and validate by running the tests.
 
-Normally, the plugin does not compile any references to `google.protobuf`, since they are pre-compiled. To force compilation of `google.protobuf`, use the option `--custom_opt=INCLUDE_GOOGLE`. 
+Normally, the plugin does not compile any references to `google.protobuf`, since they are pre-compiled. To force compilation of `google.protobuf`, use the option `--custom_opt=INCLUDE_GOOGLE`.
 
 Assuming your `google.protobuf` source files (included with all releases of `protoc`) are located in `/usr/local/include`, you can regenerate them as follows:
 
 ```sh
 protoc \
-    --plugin=protoc-gen-custom=betterproto/plugin.py \
+    --plugin=protoc-gen-custom=src/betterproto/plugin/main.py \
     --custom_opt=INCLUDE_GOOGLE \
-    --custom_out=betterproto/lib \
+    --custom_out=src/betterproto/lib \
     -I /usr/local/include/ \
     /usr/local/include/google/protobuf/*.proto
 ```

benchmarks/__init__.py

@@ -1 +0,0 @@
-

benchmarks/benchmarks.py

@@ -1,5 +1,7 @@
-import betterproto
 from dataclasses import dataclass
+from typing import List
+
+import betterproto
 
 
 @dataclass
@@ -9,6 +11,29 @@ class TestMessage(betterproto.Message):
     baz: float = betterproto.float_field(2)
 
 
+@dataclass
+class TestNestedChildMessage(betterproto.Message):
+    str_key: str = betterproto.string_field(0)
+    bytes_key: bytes = betterproto.bytes_field(1)
+    bool_key: bool = betterproto.bool_field(2)
+    float_key: float = betterproto.float_field(3)
+    int_key: int = betterproto.uint64_field(4)
+
+
+@dataclass
+class TestNestedMessage(betterproto.Message):
+    foo: TestNestedChildMessage = betterproto.message_field(0)
+    bar: TestNestedChildMessage = betterproto.message_field(1)
+    baz: TestNestedChildMessage = betterproto.message_field(2)
+
+
+@dataclass
+class TestRepeatedMessage(betterproto.Message):
+    foo_repeat: List[str] = betterproto.string_field(0)
+    bar_repeat: List[int] = betterproto.int64_field(1)
+    baz_repeat: List[bool] = betterproto.bool_field(2)
+
+
 class BenchMessage:
     """Test creation and usage a proto message."""
 
@@ -16,6 +41,30 @@ class BenchMessage:
         self.cls = TestMessage
         self.instance = TestMessage()
         self.instance_filled = TestMessage(0, "test", 0.0)
+        self.instance_filled_bytes = bytes(self.instance_filled)
+        self.instance_filled_nested = TestNestedMessage(
+            TestNestedChildMessage("foo", bytearray(b"test1"), True, 0.1234, 500),
+            TestNestedChildMessage("bar", bytearray(b"test2"), True, 3.1415, -302),
+            TestNestedChildMessage("baz", bytearray(b"test3"), False, 1e5, 300),
+        )
+        self.instance_filled_nested_bytes = bytes(self.instance_filled_nested)
+        self.instance_filled_repeated = TestRepeatedMessage(
+            [
+                "test1",
+                "test2",
+                "test3",
+                "test4",
+                "test5",
+                "test6",
+                "test7",
+                "test8",
+                "test9",
+                "test10",
+            ],
+            [2, -100, 0, 500000, 600, -425678, 1000000000, -300, 1, -694214214466],
+            [True, False, False, False, True, True, False, True, False, False],
+        )
+        self.instance_filled_repeated_bytes = bytes(self.instance_filled_repeated)
 
     def time_overhead(self):
         """Overhead in class definition."""
@@ -50,6 +99,26 @@ class BenchMessage:
         """Time serializing a message to wire."""
         bytes(self.instance_filled)
 
+    def time_deserialize(self):
+        """Time deserialize a message."""
+        TestMessage().parse(self.instance_filled_bytes)
+
+    def time_serialize_nested(self):
+        """Time serializing a nested message to wire."""
+        bytes(self.instance_filled_nested)
+
+    def time_deserialize_nested(self):
+        """Time deserialize a nested message."""
+        TestNestedMessage().parse(self.instance_filled_nested_bytes)
+
+    def time_serialize_repeated(self):
+        """Time serializing a repeated message to wire."""
+        bytes(self.instance_filled_repeated)
+
+    def time_deserialize_repeated(self):
+        """Time deserialize a repeated message."""
+        TestRepeatedMessage().parse(self.instance_filled_repeated_bytes)
+
 
 class MemSuite:
     def setup(self):

betterproto-extras/.gitignore

@@ -0,0 +1,72 @@
+/target
+
+# Byte-compiled / optimized / DLL files
+__pycache__/
+.pytest_cache/
+*.py[cod]
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+.venv/
+env/
+bin/
+build/
+develop-eggs/
+dist/
+eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+include/
+man/
+venv/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+pip-selfcheck.json
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.cache
+nosetests.xml
+coverage.xml
+
+# Translations
+*.mo
+
+# Mr Developer
+.mr.developer.cfg
+.project
+.pydevproject
+
+# Rope
+.ropeproject
+
+# Django stuff:
+*.log
+*.pot
+
+.DS_Store
+
+# Sphinx documentation
+docs/_build/
+
+# PyCharm
+.idea/
+
+# VSCode
+.vscode/
+
+# Pyenv
+.python-version

betterproto-extras/Cargo.lock

@@ -0,0 +1,383 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "anyhow"
+version = "1.0.75"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4668cab20f66d8d020e1fbc0ebe47217433c1b6c8f2040faf858554e394ace6"
+
+[[package]]
+name = "autocfg"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d468802bab17cbc0cc575e9b053f41e72aa36bfa6b7f55e3529ffa43161b97fa"
+
+[[package]]
+name = "betterproto-extras"
+version = "0.1.0"
+dependencies = [
+ "indoc 2.0.3",
+ "prost-reflect",
+ "pyo3",
+ "thiserror",
+]
+
+[[package]]
+name = "bitflags"
+version = "1.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
+
+[[package]]
+name = "bytes"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "89b2fd2a0dcf38d7971e2194b6b6eebab45ae01067456a7fd93d5547a61b70be"
+
+[[package]]
+name = "cfg-if"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
+name = "either"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a26ae43d7bcc3b814de94796a5e736d4029efb0ee900c12e2d54c993ad1a1e07"
+
+[[package]]
+name = "indoc"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bfa799dd5ed20a7e349f3b4639aa80d74549c81716d9ec4f994c9b5815598306"
+
+[[package]]
+name = "indoc"
+version = "2.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c785eefb63ebd0e33416dfcb8d6da0bf27ce752843a45632a67bf10d4d4b5c4"
+
+[[package]]
+name = "itertools"
+version = "0.10.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b0fd2260e829bddf4cb6ea802289de2f86d6a7a690192fbe91b3f46e0f2c8473"
+dependencies = [
+ "either",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.147"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4668fb0ea861c1df094127ac5f1da3409a82116a4ba74fca2e58ef927159bb3"
+
+[[package]]
+name = "lock_api"
+version = "0.4.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c1cc9717a20b1bb222f333e6a92fd32f7d8a18ddc5a3191a11af45dcbf4dcd16"
+dependencies = [
+ "autocfg",
+ "scopeguard",
+]
+
+[[package]]
+name = "memoffset"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a634b1c61a95585bd15607c6ab0c4e5b226e695ff2800ba0cdccddf208c406c"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.18.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dd8b5dd2ae5ed71462c540258bedcb51965123ad7e7ccf4b9a8cafaa4a63576d"
+
+[[package]]
+name = "parking_lot"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3742b2c103b9f06bc9fff0a37ff4912935851bee6d36f3c02bcc755bcfec228f"
+dependencies = [
+ "lock_api",
+ "parking_lot_core",
+]
+
+[[package]]
+name = "parking_lot_core"
+version = "0.9.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93f00c865fe7cabf650081affecd3871070f26767e7b2070a3ffae14c654b447"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "redox_syscall",
+ "smallvec",
+ "windows-targets",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.66"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "18fb31db3f9bddb2ea821cde30a9f70117e3f119938b5ee630b7403aa6e2ead9"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "prost"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b82eaa1d779e9a4bc1c3217db8ffbeabaae1dca241bf70183242128d48681cd"
+dependencies = [
+ "bytes",
+ "prost-derive",
+]
+
+[[package]]
+name = "prost-derive"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e5d2d8d10f3c6ded6da8b05b5fb3b8a5082514344d56c9f871412d29b4e075b4"
+dependencies = [
+ "anyhow",
+ "itertools",
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
+[[package]]
+name = "prost-reflect"
+version = "0.11.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6b823de344848e011658ac981009100818b322421676740546f8b52ed5249428"
+dependencies = [
+ "once_cell",
+ "prost",
+ "prost-types",
+]
+
+[[package]]
+name = "prost-types"
+version = "0.11.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "213622a1460818959ac1181aaeb2dc9c7f63df720db7d788b3e24eacd1983e13"
+dependencies = [
+ "prost",
+]
+
+[[package]]
+name = "pyo3"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e681a6cfdc4adcc93b4d3cf993749a4552018ee0a9b65fc0ccfad74352c72a38"
+dependencies = [
+ "cfg-if",
+ "indoc 1.0.9",
+ "libc",
+ "memoffset",
+ "parking_lot",
+ "pyo3-build-config",
+ "pyo3-ffi",
+ "pyo3-macros",
+ "unindent",
+]
+
+[[package]]
+name = "pyo3-build-config"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "076c73d0bc438f7a4ef6fdd0c3bb4732149136abd952b110ac93e4edb13a6ba5"
+dependencies = [
+ "once_cell",
+ "target-lexicon",
+]
+
+[[package]]
+name = "pyo3-ffi"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e53cee42e77ebe256066ba8aa77eff722b3bb91f3419177cf4cd0f304d3284d9"
+dependencies = [
+ "libc",
+ "pyo3-build-config",
+]
+
+[[package]]
+name = "pyo3-macros"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dfeb4c99597e136528c6dd7d5e3de5434d1ceaf487436a3f03b2d56b6fc9efd1"
+dependencies = [
+ "proc-macro2",
+ "pyo3-macros-backend",
+ "quote",
+ "syn 1.0.109",
+]
+
+[[package]]
+name = "pyo3-macros-backend"
+version = "0.19.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "947dc12175c254889edc0c02e399476c2f652b4b9ebd123aa655c224de259536"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.33"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5267fca4496028628a95160fc423a33e8b2e6af8a5302579e322e4b520293cae"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "redox_syscall"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "567664f262709473930a4bf9e51bf2ebf3348f2e748ccc50dea20646858f8f29"
+dependencies = [
+ "bitflags",
+]
+
+[[package]]
+name = "scopeguard"
+version = "1.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "94143f37725109f92c262ed2cf5e59bce7498c01bcc1502d7b9afe439a4e9f49"
+
+[[package]]
+name = "smallvec"
+version = "1.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62bb4feee49fdd9f707ef802e22365a35de4b7b299de4763d44bfea899442ff9"
+
+[[package]]
+name = "syn"
+version = "1.0.109"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.29"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c324c494eba9d92503e6f1ef2e6df781e78f6a7705a0202d9801b198807d518a"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "target-lexicon"
+version = "0.12.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9d0e916b1148c8e263850e1ebcbd046f333e0683c724876bb0da63ea4373dc8a"
+
+[[package]]
+name = "thiserror"
+version = "1.0.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97a802ec30afc17eee47b2855fc72e0c4cd62be9b4efe6591edde0ec5bd68d8f"
+dependencies = [
+ "thiserror-impl",
+]
+
+[[package]]
+name = "thiserror-impl"
+version = "1.0.47"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6bb623b56e39ab7dcd4b1b98bb6c8f8d907ed255b18de254088016b27a8ee19b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.29",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "301abaae475aa91687eb82514b328ab47a211a533026cb25fc3e519b86adfc3c"
+
+[[package]]
+name = "unindent"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e1766d682d402817b5ac4490b3c3002d91dfa0d22812f341609f97b08757359c"
+
+[[package]]
+name = "windows-targets"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a2fa6e2155d7247be68c096456083145c183cbbbc2764150dda45a87197940c"
+dependencies = [
+ "windows_aarch64_gnullvm",
+ "windows_aarch64_msvc",
+ "windows_i686_gnu",
+ "windows_i686_msvc",
+ "windows_x86_64_gnu",
+ "windows_x86_64_gnullvm",
+ "windows_x86_64_msvc",
+]
+
+[[package]]
+name = "windows_aarch64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b38e32f0abccf9987a4e3079dfb67dcd799fb61361e53e2882c3cbaf0d905d8"
+
+[[package]]
+name = "windows_aarch64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc35310971f3b2dbbf3f0690a219f40e2d9afcf64f9ab7cc1be722937c26b4bc"
+
+[[package]]
+name = "windows_i686_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a75915e7def60c94dcef72200b9a8e58e5091744960da64ec734a6c6e9b3743e"
+
+[[package]]
+name = "windows_i686_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f55c233f70c4b27f66c523580f78f1004e8b5a8b659e05a4eb49d4166cca406"
+
+[[package]]
+name = "windows_x86_64_gnu"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "53d40abd2583d23e4718fddf1ebec84dbff8381c07cae67ff7768bbf19c6718e"
+
+[[package]]
+name = "windows_x86_64_gnullvm"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0b7b52767868a23d5bab768e390dc5f5c55825b6d30b86c844ff2dc7414044cc"
+
+[[package]]
+name = "windows_x86_64_msvc"
+version = "0.48.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ed94fce61571a4006852b7389a063ab983c02eb1bb37b47f8272ce92d06d9538"

betterproto-extras/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "betterproto-extras"
+version = "0.1.0"
+edition = "2021"
+
+[lib]
+name = "betterproto_extras"
+crate-type = ["cdylib"]
+
+[dependencies]
+indoc = "2.0.3"
+prost-reflect = "0.11.5"
+pyo3 = { version = "0.19.2", features = ["abi3-py37", "extension-module"] }
+thiserror = "1.0.47"

betterproto-extras/betterproto_extras.pyi

@@ -0,0 +1,5 @@
+def deserialize(msg, data: bytes):
+    """
+    Parses the binary encoded Protobuf `data` with respect to the metadata
+    given by the betterproto message `msg`, and merges the result into `msg`.
+    """

betterproto-extras/pyproject.toml

@@ -0,0 +1,16 @@
+[build-system]
+requires = ["maturin>=1.2,<2.0"]
+build-backend = "maturin"
+
+[project]
+name = "betterproto-extras"
+requires-python = ">=3.7"
+classifiers = [
+    "Programming Language :: Rust",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Programming Language :: Python :: Implementation :: PyPy",
+]
+
+
+[tool.maturin]
+features = ["pyo3/extension-module"]

betterproto-extras/src/descriptor_pool.rs

@@ -0,0 +1,289 @@
+use crate::{
+    error::{Error, Result},
+    py_any_extras::PyAnyExtras,
+};
+use prost_reflect::{
+    prost_types::{
+        field_descriptor_proto::{Label, Type},
+        DescriptorProto, EnumDescriptorProto, EnumValueDescriptorProto, FieldDescriptorProto,
+        FileDescriptorProto, MessageOptions, OneofDescriptorProto,
+    },
+    DescriptorPool, MessageDescriptor,
+};
+use pyo3::PyAny;
+use std::sync::{Mutex, OnceLock};
+
+pub fn create_cached_descriptor(obj: &PyAny) -> Result<MessageDescriptor> {
+    static DESCRIPTOR_POOL: OnceLock<Mutex<DescriptorPool>> = OnceLock::new();
+    let mut pool = DESCRIPTOR_POOL
+        .get_or_init(|| Mutex::new(DescriptorPool::global()))
+        .lock()
+        .unwrap();
+
+    let cls = obj.getattr("__class__")?;
+    let name = format!("{}_{}", cls.qualified_name()?, cls.py_identifier());
+    if let Some(desc) = pool.get_message_by_name(&name) {
+        return Ok(desc);
+    }
+
+    let mut file = FileDescriptorProto {
+        name: Some(name.clone()),
+        ..Default::default()
+    };
+
+    add_message_to_file(name.clone(), obj, &pool, &mut file)?;
+    pool.add_file_descriptor_proto(file)?;
+    Ok(pool.get_message_by_name(&name).expect("Just registered..."))
+}
+
+fn add_message_to_file(
+    message_name: String,
+    obj: &PyAny,
+    pool: &DescriptorPool,
+    file: &mut FileDescriptorProto,
+) -> Result<()> {
+    let mut messages_to_add = vec![(message_name, obj)];
+
+    while let Some((message_name, obj)) = messages_to_add.pop() {
+        let meta = obj.get_proto_meta()?;
+        let mut message = DescriptorProto {
+            name: Some(message_name.to_string()),
+            ..Default::default()
+        };
+
+        for item in meta
+            .getattr("meta_by_field_name")?
+            .call_method0("items")?
+            .iter()?
+        {
+            let (field_name, field_meta) = item?.extract::<(&str, &PyAny)>()?;
+            message.field.push({
+                let mut field = FieldDescriptorProto {
+                    name: Some(field_name.to_string()),
+                    number: Some(field_meta.getattr("number")?.extract::<i32>()?),
+                    ..Default::default()
+                };
+                let proto_type = field_meta.getattr("proto_type")?.extract::<&str>()?;
+
+                if proto_type == "map" {
+                    field.set_type(Type::Message);
+                    let (key, val) = field_meta.getattr("map_types")?.extract::<(&str, &str)>()?;
+                    let key = map_type(key)?;
+                    let val = map_type(val)?;
+
+                    if matches!(
+                        key,
+                        Type::Float | Type::Double | Type::Bytes | Type::Message | Type::Enum
+                    ) {
+                        return Err(Error::UnsupportedMapKeyType(key));
+                    }
+
+                    let map_entry_name = format!("{field_name}Entry");
+                    field.type_name = Some(format!("{message_name}.{map_entry_name}"));
+                    field.set_label(Label::Repeated);
+                    message.nested_type.push(DescriptorProto {
+                        name: Some(map_entry_name),
+                        field: vec![
+                            {
+                                let mut proto = FieldDescriptorProto {
+                                    name: Some("key".to_string()),
+                                    number: Some(1),
+                                    ..Default::default()
+                                };
+                                proto.set_type(key);
+                                proto
+                            },
+                            {
+                                let mut proto = FieldDescriptorProto {
+                                    name: Some("value".to_string()),
+                                    number: Some(2),
+                                    ..Default::default()
+                                };
+                                proto.set_type(val);
+                                if val == Type::Message {
+                                    set_type_name(
+                                        &message_name,
+                                        meta.get_class(&format!("{field_name}.value"))?,
+                                        &mut proto,
+                                        file,
+                                        &mut messages_to_add,
+                                        pool,
+                                    )?;
+                                }
+                                proto
+                            },
+                        ],
+                        options: Some(MessageOptions {
+                            map_entry: Some(true),
+                            ..Default::default()
+                        }),
+                        ..Default::default()
+                    })
+                } else {
+                    field.set_type(map_type(proto_type)?);
+                    match field.r#type() {
+                        Type::Message => match field_meta
+                            .getattr("wraps")?
+                            .extract::<Option<&str>>()?
+                            .map(map_type)
+                            .transpose()?
+                        {
+                            Some(Type::Bool) => {
+                                field.type_name = Some("google.protobuf.BoolValue".to_string());
+                            }
+                            Some(Type::Double) => {
+                                field.type_name = Some("google.protobuf.DoubleValue".to_string());
+                            }
+                            Some(Type::Float) => {
+                                field.type_name = Some("google.protobuf.FloatValue".to_string());
+                            }
+                            Some(Type::Int64) => {
+                                field.type_name = Some("google.protobuf.Int64Value".to_string());
+                            }
+                            Some(Type::Uint64) => {
+                                field.type_name = Some("google.protobuf.UInt64Value".to_string());
+                            }
+                            Some(Type::Int32) => {
+                                field.type_name = Some("google.protobuf.Int32Value".to_string());
+                            }
+                            Some(Type::Uint32) => {
+                                field.type_name = Some("google.protobuf.UInt32Value".to_string());
+                            }
+                            Some(Type::String) => {
+                                field.type_name = Some("google.protobuf.StringValue".to_string());
+                            }
+                            Some(Type::Bytes) => {
+                                field.type_name = Some("google.protobuf.BytesValue".to_string());
+                            }
+                            Some(t) => return Err(Error::UnsupportedWrapperType(t)),
+                            None => {
+                                set_type_name(
+                                    &message_name,
+                                    meta.get_class(field_name)?,
+                                    &mut field,
+                                    file,
+                                    &mut messages_to_add,
+                                    pool,
+                                )?;
+                            }
+                        },
+                        Type::Enum => {
+                            let cls = meta.get_class(field_name)?;
+                            let cls_name =
+                                format!("{}_{}", cls.qualified_name()?, cls.py_identifier());
+                            field.type_name = Some(cls_name.to_string());
+
+                            if pool.get_enum_by_name(&cls_name).is_none()
+                                && !file.enum_type.iter().any(|item| item.name() == cls_name)
+                            {
+                                let mut proto = EnumDescriptorProto {
+                                    name: Some(cls_name.clone()),
+                                    ..Default::default()
+                                };
+
+                                for item in cls.iter()? {
+                                    let item = item?;
+                                    proto.value.push(EnumValueDescriptorProto {
+                                        number: Some(item.getattr("value")?.extract()?),
+                                        name: Some(format!(
+                                            "{}_{}",
+                                            cls_name,
+                                            item.getattr("name")?.extract::<&str>()?
+                                        )),
+                                        ..Default::default()
+                                    });
+                                }
+
+                                file.enum_type.push(proto);
+                            }
+                        }
+                        _ => {}
+                    }
+
+                    if meta.is_list_field(field_name)? {
+                        field.set_label(Label::Repeated);
+                    } else if field_meta.getattr("optional")?.extract::<bool>()? {
+                        field.proto3_optional = Some(true);
+                    }
+                }
+
+                if let Some(grp) = meta.oneof_group(field_name)? {
+                    let oneof_index = message.oneof_decl.iter().position(|x| x.name() == grp);
+
+                    match oneof_index {
+                        Some(i) => field.oneof_index = Some(i as i32),
+                        None => {
+                            message.oneof_decl.push(OneofDescriptorProto {
+                                name: Some(grp),
+                                ..Default::default()
+                            });
+                            field.oneof_index = Some((message.oneof_decl.len() - 1) as i32)
+                        }
+                    }
+                }
+
+                field
+            });
+        }
+
+        file.message_type.push(message);
+    }
+    Ok(())
+}
+
+fn map_type(str: &str) -> Result<Type> {
+    match str {
+        "enum" => Ok(Type::Enum),
+        "bool" => Ok(Type::Bool),
+        "int32" => Ok(Type::Int32),
+        "int64" => Ok(Type::Int64),
+        "uint32" => Ok(Type::Uint32),
+        "uint64" => Ok(Type::Uint64),
+        "sint32" => Ok(Type::Sint32),
+        "sint64" => Ok(Type::Sint64),
+        "float" => Ok(Type::Float),
+        "double" => Ok(Type::Double),
+        "fixed32" => Ok(Type::Fixed32),
+        "sfixed32" => Ok(Type::Sfixed32),
+        "fixed64" => Ok(Type::Fixed64),
+        "sfixed64" => Ok(Type::Sfixed64),
+        "string" => Ok(Type::String),
+        "bytes" => Ok(Type::Bytes),
+        "message" => Ok(Type::Message),
+        _ => Err(Error::UnsupportedType(str.to_string())),
+    }
+}
+
+fn set_type_name<'py>(
+    message_name: &str,
+    field_cls: &'py PyAny,
+    field: &mut FieldDescriptorProto,
+    file: &FileDescriptorProto,
+    messages_to_add: &mut Vec<(String, &'py PyAny)>,
+    pool: &DescriptorPool,
+) -> Result<()> {
+    let cls_name = field_cls.qualified_name()?;
+
+    match cls_name.as_str() {
+        "datetime.datetime" => {
+            field.type_name = Some("google.protobuf.Timestamp".to_string());
+        }
+        "datetime.timedelta" => {
+            field.type_name = Some("google.protobuf.Duration".to_string());
+        }
+        _ => {
+            let cls_name = format!("{}_{}", cls_name, field_cls.py_identifier());
+            field.type_name = Some(cls_name.clone());
+
+            if message_name != cls_name
+                && pool.get_message_by_name(&cls_name).is_none()
+                && !file.message_type.iter().any(|item| item.name() == cls_name)
+                && !messages_to_add.iter().any(|item| item.0 == cls_name)
+            {
+                messages_to_add.push((cls_name, field_cls.call0()?));
+            }
+        }
+    }
+
+    Ok(())
+}

betterproto-extras/src/error.rs

@@ -0,0 +1,29 @@
+use prost_reflect::{
+    prost::DecodeError, prost_types::field_descriptor_proto::Type, DescriptorError,
+};
+use pyo3::{exceptions::PyRuntimeError, PyErr};
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum Error {
+    #[error("Given object is not a valid betterproto message.")]
+    NoBetterprotoMessage(#[from] PyErr),
+    #[error("Unsupported type `{0}`.")]
+    UnsupportedType(String),
+    #[error("Unsupported map key type `{0:?}`.")]
+    UnsupportedMapKeyType(Type),
+    #[error("Unsupported wrapper type `{0:?}`.")]
+    UnsupportedWrapperType(Type),
+    #[error("Error on proto registration")]
+    FailedToRegisterDescriptor(#[from] DescriptorError),
+    #[error("The given binary data does not match the protobuf schema.")]
+    FailedToDecode(#[from] DecodeError),
+}
+
+pub type Result<T> = core::result::Result<T, Error>;
+
+impl From<Error> for PyErr {
+    fn from(value: Error) -> Self {
+        PyRuntimeError::new_err(value.to_string())
+    }
+}

betterproto-extras/src/lib.rs

@@ -0,0 +1,24 @@
+mod descriptor_pool;
+mod error;
+mod merging;
+mod py_any_extras;
+
+use descriptor_pool::create_cached_descriptor;
+use error::Result;
+use merging::merge_msg_into_pyobj;
+use prost_reflect::DynamicMessage;
+use pyo3::prelude::*;
+
+#[pyfunction]
+fn deserialize(obj: &PyAny, buf: &[u8]) -> Result<()> {
+    let desc = create_cached_descriptor(obj)?;
+    let msg = DynamicMessage::decode(desc, buf)?;
+    merge_msg_into_pyobj(obj, msg)?;
+    Ok(())
+}
+
+#[pymodule]
+fn betterproto_extras(_py: Python, m: &PyModule) -> PyResult<()> {
+    m.add_function(wrap_pyfunction!(deserialize, m)?)?;
+    Ok(())
+}

betterproto-extras/src/merging.rs

@@ -0,0 +1,182 @@
+use crate::{error::Result, py_any_extras::PyAnyExtras};
+use indoc::indoc;
+use prost_reflect::{
+    prost_types::{Duration, Timestamp},
+    DynamicMessage, MapKey, ReflectMessage, Value,
+};
+use pyo3::{
+    sync::GILOnceCell,
+    types::{IntoPyDict, PyBytes, PyModule},
+    Py, PyAny, PyObject, Python, ToPyObject,
+};
+
+pub fn merge_msg_into_pyobj(obj: &PyAny, mut msg: DynamicMessage) -> Result<()> {
+    for field in msg.take_fields() {
+        let field_name = field.0.name();
+        let proto_meta = obj.get_proto_meta()?;
+        obj.setattr(
+            field_name,
+            map_field_value(field_name, field.1, proto_meta)?,
+        )?;
+    }
+
+    let mut buf = vec![];
+    for field in msg.unknown_fields() {
+        field.encode(&mut buf);
+    }
+    if !buf.is_empty() {
+        let mut unknown_fields = obj.getattr("_unknown_fields")?.extract::<Vec<u8>>()?;
+        unknown_fields.append(&mut buf);
+        obj.setattr("_unknown_fields", PyBytes::new(obj.py(), &unknown_fields))?;
+    }
+
+    obj.setattr("_serialized_on_wire", true)?;
+
+    Ok(())
+}
+
+fn map_field_value(field_name: &str, field_value: Value, proto_meta: &PyAny) -> Result<PyObject> {
+    let py = proto_meta.py();
+    match field_value {
+        Value::Bool(x) => Ok(x.to_object(py)),
+        Value::Bytes(x) => Ok(PyBytes::new(py, &x).to_object(py)),
+        Value::F32(x) => Ok(x.to_object(py)),
+        Value::F64(x) => Ok(x.to_object(py)),
+        Value::I32(x) => Ok(x.to_object(py)),
+        Value::I64(x) => Ok(x.to_object(py)),
+        Value::String(x) => Ok(x.to_object(py)),
+        Value::U32(x) => Ok(x.to_object(py)),
+        Value::U64(x) => Ok(x.to_object(py)),
+        Value::Message(msg) => match msg.descriptor().full_name() {
+            "google.protobuf.BoolValue" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_bool())
+                .to_object(py)),
+            "google.protobuf.DoubleValue" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_f64())
+                .to_object(py)),
+            "google.protobuf.FloatValue" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_f32())
+                .to_object(py)),
+            "google.protobuf.Int64Value" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_i64())
+                .to_object(py)),
+            "google.protobuf.UInt64Value" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_u64())
+                .to_object(py)),
+            "google.protobuf.Int32Value" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_i32())
+                .to_object(py)),
+            "google.protobuf.UInt32Value" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_u32())
+                .to_object(py)),
+            "google.protobuf.StringValue" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_str().map(|s| s.to_string()))
+                .to_object(py)),
+            "google.protobuf.BytesValue" => Ok(msg
+                .get_field_by_number(1)
+                .and_then(|val| val.as_bytes().map(|b| PyBytes::new(py, b)))
+                .to_object(py)),
+            "google.protobuf.Timestamp" => {
+                let msg = msg.transcode_to::<Timestamp>()?;
+                Ok(create_py_datetime(&msg, py))
+            }
+            "google.protobuf.Duration" => {
+                let msg = msg.transcode_to::<Duration>()?;
+                Ok(create_py_timedelta(&msg, py))
+            }
+            _ => {
+                let obj = proto_meta.create_instance(field_name)?;
+                merge_msg_into_pyobj(obj, msg)?;
+                Ok(obj.to_object(py))
+            }
+        },
+        Value::List(ls) => Ok(ls
+            .into_iter()
+            .map(|x| map_field_value(field_name, x, proto_meta))
+            .collect::<Result<Vec<PyObject>>>()?
+            .to_object(py)),
+        Value::EnumNumber(x) => {
+            let cls = proto_meta.get_class(field_name)?;
+            Ok(cls.call1((x,))?.to_object(py))
+        }
+        Value::Map(map) => {
+            let res: Result<Vec<_>> = map
+                .into_iter()
+                .map(|(k, v)| {
+                    let key = map_key(k, py);
+                    let val = map_field_value(&format!("{field_name}.value"), v, proto_meta)?;
+                    Ok((key, val))
+                })
+                .collect();
+            Ok(res?.into_py_dict(py).to_object(py))
+        }
+    }
+}
+
+fn map_key(key: MapKey, py: Python) -> PyObject {
+    match key {
+        MapKey::Bool(x) => x.to_object(py),
+        MapKey::I32(x) => x.to_object(py),
+        MapKey::I64(x) => x.to_object(py),
+        MapKey::U32(x) => x.to_object(py),
+        MapKey::U64(x) => x.to_object(py),
+        MapKey::String(x) => x.to_object(py),
+    }
+}
+
+fn create_py_datetime(ts: &Timestamp, py: Python) -> PyObject {
+    static CONSTRUCTOR_CACHE: GILOnceCell<Py<PyAny>> = GILOnceCell::new();
+    let constructor = CONSTRUCTOR_CACHE.get_or_init(py, || {
+        let constructor = PyModule::from_code(
+            py,
+            indoc! {"
+                from datetime import datetime, timezone
+                
+                def constructor(ts):
+                    return datetime.fromtimestamp(ts, tz=timezone.utc)
+            "},
+            "",
+            "",
+        )
+        .expect("This is a valid Python module")
+        .getattr("constructor")
+        .expect("Attribute exists");
+        Py::from(constructor)
+    });
+    let ts = (ts.seconds as f64) + (ts.nanos as f64) / 1e9;
+    constructor
+        .call1(py, (ts,))
+        .expect("static function will not fail")
+}
+
+fn create_py_timedelta(duration: &Duration, py: Python) -> PyObject {
+    static CONSTRUCTOR_CACHE: GILOnceCell<Py<PyAny>> = GILOnceCell::new();
+    let constructor = CONSTRUCTOR_CACHE.get_or_init(py, || {
+        let constructor = PyModule::from_code(
+            py,
+            indoc! {"
+                from datetime import timedelta
+                
+                def constructor(s, ms):
+                    return timedelta(seconds=s, microseconds=ms)
+            "},
+            "",
+            "",
+        )
+        .expect("This is a valid Python module")
+        .getattr("constructor")
+        .expect("Attribute exists");
+        Py::from(constructor)
+    });
+    constructor
+        .call1(py, (duration.seconds as f64, (duration.nanos as f64) / 1e3))
+        .expect("static function will not fail")
+}

betterproto-extras/src/py_any_extras.rs

@@ -0,0 +1,68 @@
+use crate::error::Result;
+use pyo3::{PyAny, Py, sync::GILOnceCell};
+
+pub trait PyAnyExtras {
+    fn qualified_name(&self) -> Result<String>;
+    fn qualified_class_name(&self) -> Result<String>;
+    fn get_proto_meta(&self) -> Result<&PyAny>;
+    fn get_class(&self, field_name: &str) -> Result<&PyAny>;
+    fn create_instance(&self, field_name: &str) -> Result<&PyAny>;
+    fn is_list_field(&self, field_name: &str) -> Result<bool>;
+    fn oneof_group(&self, field_name: &str) -> Result<Option<String>>;
+    fn py_identifier(&self) -> u64;
+}
+
+impl PyAnyExtras for PyAny {
+    fn qualified_name(&self) -> Result<String> {
+        let module = self.getattr("__module__")?;
+        let name = self.getattr("__name__")?;
+        Ok(format!("{module}.{name}"))
+    }
+
+    fn qualified_class_name(&self) -> Result<String> {
+        self.getattr("__class__")?.qualified_name()
+    }
+
+    fn get_proto_meta(&self) -> Result<&PyAny> {
+        Ok(self.getattr("_betterproto")?)
+    }
+
+    fn get_class(&self, field_name: &str) -> Result<&PyAny> {
+        let cls = self.getattr("cls_by_field")?.get_item(field_name)?;
+        Ok(cls)
+    }
+
+    fn create_instance(&self, field_name: &str) -> Result<&PyAny> {
+        Ok(self.get_class(field_name)?.call0()?)
+    }
+
+    fn is_list_field(&self, field_name: &str) -> Result<bool> {
+        let cls = self.getattr("default_gen")?.get_item(field_name)?;
+        let module = cls.getattr("__module__")?;
+        let name = cls.getattr("__name__")?;
+        Ok(module.to_string() == "builtins" && name.to_string() == "list")
+    }
+
+    fn oneof_group(&self, field_name: &str) -> Result<Option<String>> {
+        let opt = self
+            .getattr("oneof_group_by_field")?
+            .call_method1("get", (field_name,))?
+            .extract()?;
+        Ok(opt)
+    }
+
+    fn py_identifier(&self) -> u64 {
+        static FUN_CACHE: GILOnceCell<Py<PyAny>> = GILOnceCell::new();
+        let py = self.py();
+        let fun = FUN_CACHE.get_or_init(py, || {
+            let fun = py
+                .eval("id", None, None)
+                .expect("This is a valid Python expression");
+            Py::from(fun)
+        });
+        fun.call1(py, (self,))
+            .expect("Identity function is callable")
+            .extract::<u64>(py)
+            .expect("Identity function always returns an integer")
+    }
+}

docs/index.rst

@@ -12,7 +12,7 @@ Features:
 - Generated messages are both binary & JSON serializable
 - Messages use relevant python types, e.g. ``Enum``, ``datetime`` and ``timedelta``
   objects
-- ``async``/``await`` support for gRPC Clients
+- ``async``/``await`` support for gRPC Clients and Servers
 - Generates modern, readable, idiomatic python code
 
 Contents:

docs/quick-start.rst

@@ -100,7 +100,7 @@ Async gRPC Support
 ++++++++++++++++++
 
 The generated code includes `grpclib <https://grpclib.readthedocs.io/en/latest>`_ based
-stub (client) classes for rpc services declared in the input proto files.
+stub (client and server) classes for rpc services declared in the input proto files.
 It is enabled by default.
 
 
@@ -160,6 +160,36 @@ The generated client can be used like so:
     EchoStreamResponse(value='hello')
 
 
+The server-facing stubs can be used to implement a Python
+gRPC server.
+To use them, simply subclass the base class in the generated files and override the
+service methods:
+
+.. code-block:: python
+
+    from echo import EchoBase
+    from grpclib.server import Server
+    from typing import AsyncIterator
+
+
+    class EchoService(EchoBase):
+        async def echo(self, value: str, extra_times: int) -> "EchoResponse":
+            return value
+
+        async def echo_stream(
+            self, value: str, extra_times: int
+        ) -> AsyncIterator["EchoStreamResponse"]:
+            for _ in range(extra_times):
+                yield value
+
+
+    async def start_server():
+        HOST = "127.0.0.1"
+        PORT = 1337
+        server = Server([EchoService()])
+        await server.start(HOST, PORT)
+        await server.serve_forever()
+
 JSON
 ++++
 Message objects include :meth:`betterproto.Message.to_json` and

example.py

@@ -0,0 +1,55 @@
+# dev tests
+# to be deleted later
+
+import betterproto
+from dataclasses import dataclass
+from typing import Dict, List, Optional
+
+@dataclass(repr=False)
+class Baz(betterproto.Message):
+    a: float = betterproto.float_field(1, group = "x")
+    b: int = betterproto.int64_field(2, group = "x")
+    c: float = betterproto.float_field(3, group = "y")
+    d: int = betterproto.int64_field(4, group = "y")
+    e: Optional[int] = betterproto.int32_field(5, group = "_e", optional = True)
+
+@dataclass(repr=False)
+class Foo(betterproto.Message):
+    x: int = betterproto.int32_field(1)
+    y: float = betterproto.double_field(2)
+    z: List[Baz] = betterproto.message_field(3)
+
+class Enm(betterproto.Enum):
+    A = 0
+    B = 1
+    C = 2
+
+@dataclass(repr=False)
+class Bar(betterproto.Message):
+    foo1: Foo = betterproto.message_field(1)
+    foo2: Foo = betterproto.message_field(2)
+    packed: List[int] = betterproto.int64_field(3)
+    enm: Enm = betterproto.enum_field(4)
+    map: Dict[int, bool] = betterproto.map_field(5, betterproto.TYPE_INT64, betterproto.TYPE_BOOL)
+    maybe: Optional[bool] = betterproto.message_field(6, wraps=betterproto.TYPE_BOOL)
+    bts: bytes = betterproto.bytes_field(7)
+
+# Serialization has not been changed yet. So nothing unusual here
+buffer = bytes(
+    Bar(
+        foo1=Foo(1, 2.34),
+        foo2=Foo(3, 4.56, [Baz(a = 1.234), Baz(b = 5, e=1), Baz(b = 2, d = 3)]),
+        packed=[5, 3, 1],
+        enm=Enm.B,
+        map={
+            1: True,
+            42: False
+        },
+        maybe=True,
+        bts=b'Hi There!'
+    )
+)
+
+# Native deserialization happening here
+bar = Bar().parse(buffer)
+print(bar)

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "betterproto"
-version = "2.0.0b2"
+version = "2.0.0b6"
 description = "A better Protobuf / gRPC generator & library"
 authors = ["Daniel G. Taylor <danielgtaylor@gmail.com>"]
 readme = "README.md"
@@ -12,53 +12,118 @@ packages = [
 ]
 
 [tool.poetry.dependencies]
-python = "^3.6"
-backports-datetime-fromisoformat = { version = "^1.0.0", python = "<3.7" }
-black = { version = ">=19.3b0", optional = true }
-dataclasses = { version = "^0.7", python = ">=3.6, <3.7" }
+python = "^3.7"
+black = { version = ">=23.1.0", optional = true }
 grpclib = "^0.4.1"
-jinja2 = { version = "^2.11.2", optional = true }
-protobuf = { version = "^3.12.2", optional = true }
+importlib-metadata = { version = ">=1.6.0", python = "<3.8" }
+jinja2 = { version = ">=3.0.3", optional = true }
+python-dateutil = "^2.8"
+isort = {version = "^5.11.5", optional = true}
+betterproto-extras = { path = "betterproto-extras" }
 
 [tool.poetry.dev-dependencies]
-black = "^20.8b1"
+asv = "^0.4.2"
 bpython = "^0.19"
-grpcio-tools = "^1.30.0"
-jinja2 = "^2.11.2"
-mypy = "^0.770"
-poethepoet = "^0.5.0"
-protobuf = "^3.12.2"
-pytest = "^5.4.2"
+grpcio-tools = "^1.54.2"
+jinja2 = ">=3.0.3"
+mypy = "^0.930"
+poethepoet = ">=0.9.0"
+protobuf = "^4.21.6"
+pytest = "^6.2.5"
 pytest-asyncio = "^0.12.0"
 pytest-cov = "^2.9.0"
 pytest-mock = "^3.1.1"
-tox = "^3.15.1"
 sphinx = "3.1.2"
 sphinx-rtd-theme = "0.5.0"
-asv = "^0.4.2"
+tomlkit = "^0.7.0"
+tox = "^3.15.1"
+pre-commit = "^2.17.0"
+pydantic = ">=1.8.0"
+
 
 [tool.poetry.scripts]
 protoc-gen-python_betterproto = "betterproto.plugin:main"
 
 [tool.poetry.extras]
-compiler = ["black", "jinja2", "protobuf"]
+compiler = ["black", "isort", "jinja2"]
+
 
-[tool.poe.tasks]
 # Dev workflow tasks
-generate    = { script = "tests.generate:main", help = "Generate test cases (do this once before running test)" }
-test        = { cmd = "pytest --cov src", help = "Run tests" }
-types       = { cmd = "mypy src --ignore-missing-imports", help = "Check types with mypy" }
-format      = { cmd = "black . --exclude tests/output_",   help = "Apply black formatting to source code" }
-clean       = { cmd = "rm -rf .coverage .mypy_cache .pytest_cache dist betterproto.egg-info **/__pycache__ tests/output_*", help = "Clean out generated files from the workspace" }
-docs        = { cmd = "sphinx-build docs docs/build", help = "Build the sphinx docs"}
-bench       = { shell = "asv run master^! && asv run HEAD^! && asv compare master HEAD", help = "Benchmark current commit vs. master branch"}
+
+[tool.poe.tasks.generate]
+script = "tests.generate:main"
+help = "Generate test cases (do this once before running test)"
+
+[tool.poe.tasks.test]
+cmd = "pytest"
+help = "Run tests"
+
+[tool.poe.tasks.types]
+cmd  = "mypy src --ignore-missing-imports"
+help = "Check types with mypy"
+
+[tool.poe.tasks.format]
+cmd  = "black . --exclude tests/output_ --target-version py310"
+help = "Apply black formatting to source code"
+
+[tool.poe.tasks.docs]
+cmd  = "sphinx-build docs docs/build"
+help = "Build the sphinx docs"
+
+[tool.poe.tasks.bench]
+shell = "asv run master^! && asv run HEAD^! && asv compare master HEAD"
+help  = "Benchmark current commit vs. master branch"
+
+[tool.poe.tasks.clean]
+cmd  = """
+rm -rf .asv .coverage .mypy_cache .pytest_cache
+       dist betterproto.egg-info **/__pycache__
+       testsoutput_*
+"""
+help = "Clean out generated files from the workspace"
+
+[tool.poe.tasks.generate_lib]
+cmd = """
+protoc
+    --plugin=protoc-gen-custom=src/betterproto/plugin/main.py
+    --custom_opt=INCLUDE_GOOGLE
+    --custom_out=src/betterproto/lib
+    -I C:\\work\\include
+    C:\\work\\include\\google\\protobuf\\**\\*.proto
+"""
+help = "Regenerate the types in betterproto.lib.google"
 
 # CI tasks
-full-test   = { shell = "poe generate && tox", help = "Run tests with multiple pythons" }
-check-style = { cmd = "black . --check --diff --exclude tests/output_", help = "Check if code style is correct"}
+
+[tool.poe.tasks.full-test]
+shell = "poe generate && tox"
+help = "Run tests with multiple pythons"
+
+[tool.poe.tasks.check-style]
+cmd = "black . --check --diff"
+help = "Check if code style is correct"
+
+[tool.isort]
+py_version = 37
+profile = "black"
+force_single_line = false
+combine_as_imports = true
+lines_after_imports = 2
+include_trailing_comma = true
+force_grid_wrap = 2
+src_paths = ["src", "tests"]
 
 [tool.black]
-target-version = ['py36']
+target-version = ['py37']
+
+[tool.doc8]
+paths = ["docs"]
+max_line_length = 88
+
+[tool.doc8.ignore_path_errors]
+"docs/migrating.rst" = [
+    "D001",  # contains table which is longer than 88 characters long
+]
 
 [tool.coverage.run]
 omit = ["betterproto/tests/*"]
@@ -67,7 +132,7 @@ omit = ["betterproto/tests/*"]
 legacy_tox_ini = """
 [tox]
 isolated_build = true
-envlist = py36, py37, py38
+envlist = py37, py38, py310
 
 [testenv]
 whitelist_externals = poetry

src/betterproto/_types.py

@@ -1,7 +1,12 @@
-from typing import TYPE_CHECKING, TypeVar
+from typing import (
+    TYPE_CHECKING,
+    TypeVar,
+)
+
 
 if TYPE_CHECKING:
     from grpclib._typing import IProtoMessage
+
     from . import Message
 
 # Bound type variable to allow methods to return `self` of subclasses

src/betterproto/_version.py

@@ -0,0 +1,7 @@
+try:
+    from importlib import metadata
+except ImportError:  # for Python<3.8
+    import importlib_metadata as metadata  # type: ignore
+
+
+__version__ = metadata.version("betterproto")

src/betterproto/casing.py

@@ -1,6 +1,7 @@
 import keyword
 import re
 
+
 # Word delimiters and symbols that will not be preserved when re-casing.
 # language=PythonRegExp
 SYMBOLS = "[^a-zA-Z0-9]*"

src/betterproto/compile/importing.py

@@ -1,11 +1,18 @@
 import os
 import re
-from typing import Dict, List, Set, Tuple, Type
+from typing import (
+    Dict,
+    List,
+    Set,
+    Tuple,
+    Type,
+)
 
 from ..casing import safe_snake_case
 from ..lib.google import protobuf as google_protobuf
 from .naming import pythonize_class_name
 
+
 WRAPPER_TYPES: Dict[str, Type] = {
     ".google.protobuf.DoubleValue": google_protobuf.DoubleValue,
     ".google.protobuf.FloatValue": google_protobuf.FloatValue,
@@ -36,7 +43,7 @@ def parse_source_type_name(field_type_name: str) -> Tuple[str, str]:
 
 
 def get_type_reference(
-    package: str, imports: set, source_type: str, unwrap: bool = True
+    *, package: str, imports: set, source_type: str, unwrap: bool = True
 ) -> str:
     """
     Return a Python type name for a proto type reference. Adds the import if
@@ -100,8 +107,9 @@ def reference_descendent(
     current_package: List[str], imports: Set[str], py_package: List[str], py_type: str
 ) -> str:
     """
-    Returns a reference to a python type in a package that is a descendent of the current package,
-    and adds the required import that is aliased to avoid name conflicts.
+    Returns a reference to a python type in a package that is a descendent of the
+    current package, and adds the required import that is aliased to avoid name
+    conflicts.
     """
     importing_descendent = py_package[len(current_package) :]
     string_from = ".".join(importing_descendent[:-1])
@@ -119,8 +127,9 @@ def reference_ancestor(
     current_package: List[str], imports: Set[str], py_package: List[str], py_type: str
 ) -> str:
     """
-    Returns a reference to a python type in a package which is an ancestor to the current package,
-    and adds the required import that is aliased (if possible) to avoid name conflicts.
+    Returns a reference to a python type in a package which is an ancestor to the
+    current package, and adds the required import that is aliased (if possible) to avoid
+    name conflicts.
 
     Adds trailing __ to avoid name mangling (python.org/dev/peps/pep-0008/#id34).
     """
@@ -141,10 +150,10 @@ def reference_cousin(
     current_package: List[str], imports: Set[str], py_package: List[str], py_type: str
 ) -> str:
     """
-    Returns a reference to a python type in a package that is not descendent, ancestor or sibling,
-    and adds the required import that is aliased to avoid name conflicts.
+    Returns a reference to a python type in a package that is not descendent, ancestor
+    or sibling, and adds the required import that is aliased to avoid name conflicts.
     """
-    shared_ancestry = os.path.commonprefix([current_package, py_package])
+    shared_ancestry = os.path.commonprefix([current_package, py_package])  # type: ignore
     distance_up = len(current_package) - len(shared_ancestry)
     string_from = f".{'.' * distance_up}" + ".".join(
         py_package[len(shared_ancestry) : -1]

src/betterproto/grpc/grpclib_client.py

@@ -15,17 +15,22 @@ from typing import (
 
 import grpclib.const
 
-from .._types import ST, T
 
 if TYPE_CHECKING:
     from grpclib.client import Channel
     from grpclib.metadata import Deadline
 
+    from .._types import (
+        ST,
+        IProtoMessage,
+        Message,
+        T,
+    )
 
-_Value = Union[str, bytes]
-_MetadataLike = Union[Mapping[str, _Value], Collection[Tuple[str, _Value]]]
-_MessageLike = Union[T, ST]
-_MessageSource = Union[Iterable[ST], AsyncIterable[ST]]
+
+Value = Union[str, bytes]
+MetadataLike = Union[Mapping[str, Value], Collection[Tuple[str, Value]]]
+MessageSource = Union[Iterable["IProtoMessage"], AsyncIterable["IProtoMessage"]]
 
 
 class ServiceStub(ABC):
@@ -39,7 +44,7 @@ class ServiceStub(ABC):
         *,
         timeout: Optional[float] = None,
         deadline: Optional["Deadline"] = None,
-        metadata: Optional[_MetadataLike] = None,
+        metadata: Optional[MetadataLike] = None,
     ) -> None:
         self.channel = channel
         self.timeout = timeout
@@ -50,7 +55,7 @@ class ServiceStub(ABC):
         self,
         timeout: Optional[float],
         deadline: Optional["Deadline"],
-        metadata: Optional[_MetadataLike],
+        metadata: Optional[MetadataLike],
     ):
         return {
             "timeout": self.timeout if timeout is None else timeout,
@@ -61,13 +66,13 @@ class ServiceStub(ABC):
     async def _unary_unary(
         self,
         route: str,
-        request: _MessageLike,
-        response_type: Type[T],
+        request: "IProtoMessage",
+        response_type: Type["T"],
         *,
         timeout: Optional[float] = None,
         deadline: Optional["Deadline"] = None,
-        metadata: Optional[_MetadataLike] = None,
-    ) -> T:
+        metadata: Optional[MetadataLike] = None,
+    ) -> "T":
         """Make a unary request and return the response."""
         async with self.channel.request(
             route,
@@ -84,13 +89,13 @@ class ServiceStub(ABC):
     async def _unary_stream(
         self,
         route: str,
-        request: _MessageLike,
-        response_type: Type[T],
+        request: "IProtoMessage",
+        response_type: Type["T"],
         *,
         timeout: Optional[float] = None,
         deadline: Optional["Deadline"] = None,
-        metadata: Optional[_MetadataLike] = None,
-    ) -> AsyncIterator[T]:
+        metadata: Optional[MetadataLike] = None,
+    ) -> AsyncIterator["T"]:
         """Make a unary request and return the stream response iterator."""
         async with self.channel.request(
             route,
@@ -106,14 +111,14 @@ class ServiceStub(ABC):
     async def _stream_unary(
         self,
         route: str,
-        request_iterator: _MessageSource,
-        request_type: Type[ST],
-        response_type: Type[T],
+        request_iterator: MessageSource,
+        request_type: Type["IProtoMessage"],
+        response_type: Type["T"],
         *,
         timeout: Optional[float] = None,
         deadline: Optional["Deadline"] = None,
-        metadata: Optional[_MetadataLike] = None,
-    ) -> T:
+        metadata: Optional[MetadataLike] = None,
+    ) -> "T":
         """Make a stream request and return the response."""
         async with self.channel.request(
             route,
@@ -130,14 +135,14 @@ class ServiceStub(ABC):
     async def _stream_stream(
         self,
         route: str,
-        request_iterator: _MessageSource,
-        request_type: Type[ST],
-        response_type: Type[T],
+        request_iterator: MessageSource,
+        request_type: Type["IProtoMessage"],
+        response_type: Type["T"],
         *,
         timeout: Optional[float] = None,
         deadline: Optional["Deadline"] = None,
-        metadata: Optional[_MetadataLike] = None,
-    ) -> AsyncIterator[T]:
+        metadata: Optional[MetadataLike] = None,
+    ) -> AsyncIterator["T"]:
         """
         Make a stream request and return an AsyncIterator to iterate over response
         messages.
@@ -161,7 +166,7 @@ class ServiceStub(ABC):
                 raise
 
     @staticmethod
-    async def _send_messages(stream, messages: _MessageSource):
+    async def _send_messages(stream, messages: MessageSource):
         if isinstance(messages, AsyncIterable):
             async for message in messages:
                 await stream.send_message(message)

src/betterproto/grpc/grpclib_server.py

@@ -0,0 +1,33 @@
+from abc import ABC
+from collections.abc import AsyncIterable
+from typing import (
+    Any,
+    Callable,
+    Dict,
+)
+
+import grpclib
+import grpclib.server
+
+
+class ServiceBase(ABC):
+    """
+    Base class for async gRPC servers.
+    """
+
+    async def _call_rpc_handler_server_stream(
+        self,
+        handler: Callable,
+        stream: grpclib.server.Stream,
+        request: Any,
+    ) -> None:
+        response_iter = handler(request)
+        # check if response is actually an AsyncIterator
+        # this might be false if the method just returns without
+        # yielding at least once
+        # in that case, we just interpret it as an empty iterator
+        if isinstance(response_iter, AsyncIterable):
+            async for response_message in response_iter:
+                await stream.send_message(response_message)
+        else:
+            response_iter.close()

src/betterproto/grpc/util/async_channel.py

@@ -1,5 +1,13 @@
 import asyncio
-from typing import AsyncIterable, AsyncIterator, Iterable, Optional, TypeVar, Union
+from typing import (
+    AsyncIterable,
+    AsyncIterator,
+    Iterable,
+    Optional,
+    TypeVar,
+    Union,
+)
+
 
 T = TypeVar("T")
 
@@ -70,7 +78,7 @@ class AsyncChannel(AsyncIterable[T]):
     """
 
     def __init__(self, *, buffer_limit: int = 0, close: bool = False):
-        self._queue: asyncio.Queue[Union[T, object]] = asyncio.Queue(buffer_limit)
+        self._queue: asyncio.Queue[T] = asyncio.Queue(buffer_limit)
         self._closed = False
         self._waiting_receivers: int = 0
         # Track whether flush has been invoked so it can only happen once

src/betterproto/lib/google/protobuf/compiler/__init__.py

@@ -0,0 +1,152 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# sources: google/protobuf/compiler/plugin.proto
+# plugin: python-betterproto
+# This file has been @generated
+from dataclasses import dataclass
+from typing import List
+
+import betterproto
+import betterproto.lib.google.protobuf as betterproto_lib_google_protobuf
+
+
+class CodeGeneratorResponseFeature(betterproto.Enum):
+    """Sync with code_generator.h."""
+
+    FEATURE_NONE = 0
+    FEATURE_PROTO3_OPTIONAL = 1
+
+
+@dataclass(eq=False, repr=False)
+class Version(betterproto.Message):
+    """The version number of protocol compiler."""
+
+    major: int = betterproto.int32_field(1)
+    minor: int = betterproto.int32_field(2)
+    patch: int = betterproto.int32_field(3)
+    suffix: str = betterproto.string_field(4)
+    """
+    A suffix for alpha, beta or rc release, e.g., "alpha-1", "rc2". It should
+    be empty for mainline stable releases.
+    """
+
+
+@dataclass(eq=False, repr=False)
+class CodeGeneratorRequest(betterproto.Message):
+    """An encoded CodeGeneratorRequest is written to the plugin's stdin."""
+
+    file_to_generate: List[str] = betterproto.string_field(1)
+    """
+    The .proto files that were explicitly listed on the command-line.  The code
+    generator should generate code only for these files.  Each file's
+    descriptor will be included in proto_file, below.
+    """
+
+    parameter: str = betterproto.string_field(2)
+    """The generator parameter passed on the command-line."""
+
+    proto_file: List[
+        "betterproto_lib_google_protobuf.FileDescriptorProto"
+    ] = betterproto.message_field(15)
+    """
+    FileDescriptorProtos for all files in files_to_generate and everything they
+    import.  The files will appear in topological order, so each file appears
+    before any file that imports it. protoc guarantees that all proto_files
+    will be written after the fields above, even though this is not technically
+    guaranteed by the protobuf wire format.  This theoretically could allow a
+    plugin to stream in the FileDescriptorProtos and handle them one by one
+    rather than read the entire set into memory at once.  However, as of this
+    writing, this is not similarly optimized on protoc's end -- it will store
+    all fields in memory at once before sending them to the plugin. Type names
+    of fields and extensions in the FileDescriptorProto are always fully
+    qualified.
+    """
+
+    compiler_version: "Version" = betterproto.message_field(3)
+    """The version number of protocol compiler."""
+
+
+@dataclass(eq=False, repr=False)
+class CodeGeneratorResponse(betterproto.Message):
+    """The plugin writes an encoded CodeGeneratorResponse to stdout."""
+
+    error: str = betterproto.string_field(1)
+    """
+    Error message.  If non-empty, code generation failed.  The plugin process
+    should exit with status code zero even if it reports an error in this way.
+    This should be used to indicate errors in .proto files which prevent the
+    code generator from generating correct code.  Errors which indicate a
+    problem in protoc itself -- such as the input CodeGeneratorRequest being
+    unparseable -- should be reported by writing a message to stderr and
+    exiting with a non-zero status code.
+    """
+
+    supported_features: int = betterproto.uint64_field(2)
+    """
+    A bitmask of supported features that the code generator supports. This is a
+    bitwise "or" of values from the Feature enum.
+    """
+
+    file: List["CodeGeneratorResponseFile"] = betterproto.message_field(15)
+
+
+@dataclass(eq=False, repr=False)
+class CodeGeneratorResponseFile(betterproto.Message):
+    """Represents a single generated file."""
+
+    name: str = betterproto.string_field(1)
+    """
+    The file name, relative to the output directory.  The name must not contain
+    "." or ".." components and must be relative, not be absolute (so, the file
+    cannot lie outside the output directory).  "/" must be used as the path
+    separator, not "\". If the name is omitted, the content will be appended to
+    the previous file.  This allows the generator to break large files into
+    small chunks, and allows the generated text to be streamed back to protoc
+    so that large files need not reside completely in memory at one time.  Note
+    that as of this writing protoc does not optimize for this -- it will read
+    the entire CodeGeneratorResponse before writing files to disk.
+    """
+
+    insertion_point: str = betterproto.string_field(2)
+    """
+    If non-empty, indicates that the named file should already exist, and the
+    content here is to be inserted into that file at a defined insertion point.
+    This feature allows a code generator to extend the output produced by
+    another code generator.  The original generator may provide insertion
+    points by placing special annotations in the file that look like:
+    @@protoc_insertion_point(NAME) The annotation can have arbitrary text
+    before and after it on the line, which allows it to be placed in a comment.
+    NAME should be replaced with an identifier naming the point -- this is what
+    other generators will use as the insertion_point.  Code inserted at this
+    point will be placed immediately above the line containing the insertion
+    point (thus multiple insertions to the same point will come out in the
+    order they were added). The double-@ is intended to make it unlikely that
+    the generated code could contain things that look like insertion points by
+    accident. For example, the C++ code generator places the following line in
+    the .pb.h files that it generates:   //
+    @@protoc_insertion_point(namespace_scope) This line appears within the
+    scope of the file's package namespace, but outside of any particular class.
+    Another plugin can then specify the insertion_point "namespace_scope" to
+    generate additional classes or other declarations that should be placed in
+    this scope. Note that if the line containing the insertion point begins
+    with whitespace, the same whitespace will be added to every line of the
+    inserted text.  This is useful for languages like Python, where indentation
+    matters.  In these languages, the insertion point comment should be
+    indented the same amount as any inserted code will need to be in order to
+    work correctly in that context. The code generator that generates the
+    initial file and the one which inserts into it must both run as part of a
+    single invocation of protoc. Code generators are executed in the order in
+    which they appear on the command line. If |insertion_point| is present,
+    |name| must also be present.
+    """
+
+    content: str = betterproto.string_field(15)
+    """The file contents."""
+
+    generated_code_info: "betterproto_lib_google_protobuf.GeneratedCodeInfo" = (
+        betterproto.message_field(16)
+    )
+    """
+    Information describing the file content being inserted. If an insertion
+    point is used, this information will be appropriately offset and inserted
+    into the code generation metadata for the generated files.
+    """

src/betterproto/plugin/compiler.py

@@ -1,8 +1,10 @@
 import os.path
 
+
 try:
     # betterproto[compiler] specific dependencies
     import black
+    import isort.api
     import jinja2
 except ImportError as err:
     print(
@@ -19,7 +21,6 @@ from .models import OutputTemplate
 
 
 def outputfile_compiler(output_file: OutputTemplate) -> str:
-
     templates_folder = os.path.abspath(
         os.path.join(os.path.dirname(__file__), "..", "templates")
     )
@@ -31,7 +32,19 @@ def outputfile_compiler(output_file: OutputTemplate) -> str:
     )
     template = env.get_template("template.py.j2")
 
-    return black.format_str(
-        template.render(output_file=output_file),
-        mode=black.FileMode(target_versions={black.TargetVersion.PY37}),
+    code = template.render(output_file=output_file)
+    code = isort.api.sort_code_string(
+        code=code,
+        show_diff=False,
+        py_version=37,
+        profile="black",
+        combine_as_imports=True,
+        lines_after_imports=2,
+        quiet=True,
+        force_grid_wrap=2,
+        known_third_party=["grpclib", "betterproto"],
+    )
+    return black.format_str(
+        src_contents=code,
+        mode=black.Mode(),
     )

src/betterproto/plugin/main.py

@@ -3,8 +3,11 @@
 import os
 import sys
 
-from google.protobuf.compiler import plugin_pb2 as plugin
-
+from betterproto.lib.google.protobuf.compiler import (
+    CodeGeneratorRequest,
+    CodeGeneratorResponse,
+)
+from betterproto.plugin.models import monkey_patch_oneof_index
 from betterproto.plugin.parser import generate_code
 
 
@@ -13,19 +16,19 @@ def main() -> None:
     # Read request message from stdin
     data = sys.stdin.buffer.read()
 
+    # Apply Work around for proto2/3 difference in protoc messages
+    monkey_patch_oneof_index()
+
     # Parse request
-    request = plugin.CodeGeneratorRequest()
-    request.ParseFromString(data)
+    request = CodeGeneratorRequest()
+    request.parse(data)
 
     dump_file = os.getenv("BETTERPROTO_DUMP")
     if dump_file:
         dump_request(dump_file, request)
 
-    # Create response
-    response = plugin.CodeGeneratorResponse()
-
     # Generate code
-    generate_code(request, response)
+    response = generate_code(request)
 
     # Serialise response message
     output = response.SerializeToString()
@@ -34,7 +37,7 @@ def main() -> None:
     sys.stdout.buffer.write(output)
 
 
-def dump_request(dump_file: str, request: plugin.CodeGeneratorRequest) -> None:
+def dump_request(dump_file: str, request: CodeGeneratorRequest) -> None:
     """
     For developers: Supports running plugin.py standalone so its possible to debug it.
     Run protoc (or generate.py) with BETTERPROTO_DUMP="yourfile.bin" to write the request to a file.

src/betterproto/plugin/models.py

@@ -29,41 +29,60 @@ instantiating field `A` with parent message `B` should add a
 reference to `A` to `B`'s `fields` attribute.
 """
 
+
+import builtins
 import re
 import textwrap
-from dataclasses import dataclass, field
-from typing import Dict, Iterator, List, Optional, Set, Text, Type, Union
+from dataclasses import (
+    dataclass,
+    field,
+)
+from typing import (
+    Dict,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Set,
+    Type,
+    Union,
+)
 
 import betterproto
+from betterproto import which_one_of
+from betterproto.casing import sanitize_name
+from betterproto.compile.importing import (
+    get_type_reference,
+    parse_source_type_name,
+)
+from betterproto.compile.naming import (
+    pythonize_class_name,
+    pythonize_field_name,
+    pythonize_method_name,
+)
+from betterproto.lib.google.protobuf import (
+    DescriptorProto,
+    EnumDescriptorProto,
+    Field,
+    FieldDescriptorProto,
+    FieldDescriptorProtoLabel,
+    FieldDescriptorProtoType,
+    FileDescriptorProto,
+    MethodDescriptorProto,
+)
+from betterproto.lib.google.protobuf.compiler import CodeGeneratorRequest
 
 from ..casing import sanitize_name
-from ..compile.importing import get_type_reference, parse_source_type_name
+from ..compile.importing import (
+    get_type_reference,
+    parse_source_type_name,
+)
 from ..compile.naming import (
     pythonize_class_name,
     pythonize_field_name,
     pythonize_method_name,
 )
 
-try:
-    # betterproto[compiler] specific dependencies
-    from google.protobuf.compiler import plugin_pb2 as plugin
-    from google.protobuf.descriptor_pb2 import (
-        DescriptorProto,
-        EnumDescriptorProto,
-        FieldDescriptorProto,
-        FileDescriptorProto,
-        MethodDescriptorProto,
-    )
-except ImportError as err:
-    print(
-        "\033[31m"
-        f"Unable to import `{err.name}` from betterproto plugin! "
-        "Please ensure that you've installed betterproto as "
-        '`pip install "betterproto[compiler]"` so that compiler dependencies '
-        "are included."
-        "\033[0m"
-    )
-    raise SystemExit(1)
 
 # Create a unique placeholder to deal with
 # https://stackoverflow.com/questions/51575931/class-inheritance-in-python-3-7-dataclasses
@@ -71,67 +90,84 @@ PLACEHOLDER = object()
 
 # Organize proto types into categories
 PROTO_FLOAT_TYPES = (
-    FieldDescriptorProto.TYPE_DOUBLE,  # 1
-    FieldDescriptorProto.TYPE_FLOAT,  # 2
+    FieldDescriptorProtoType.TYPE_DOUBLE,  # 1
+    FieldDescriptorProtoType.TYPE_FLOAT,  # 2
 )
 PROTO_INT_TYPES = (
-    FieldDescriptorProto.TYPE_INT64,  # 3
-    FieldDescriptorProto.TYPE_UINT64,  # 4
-    FieldDescriptorProto.TYPE_INT32,  # 5
-    FieldDescriptorProto.TYPE_FIXED64,  # 6
-    FieldDescriptorProto.TYPE_FIXED32,  # 7
-    FieldDescriptorProto.TYPE_UINT32,  # 13
-    FieldDescriptorProto.TYPE_SFIXED32,  # 15
-    FieldDescriptorProto.TYPE_SFIXED64,  # 16
-    FieldDescriptorProto.TYPE_SINT32,  # 17
-    FieldDescriptorProto.TYPE_SINT64,  # 18
+    FieldDescriptorProtoType.TYPE_INT64,  # 3
+    FieldDescriptorProtoType.TYPE_UINT64,  # 4
+    FieldDescriptorProtoType.TYPE_INT32,  # 5
+    FieldDescriptorProtoType.TYPE_FIXED64,  # 6
+    FieldDescriptorProtoType.TYPE_FIXED32,  # 7
+    FieldDescriptorProtoType.TYPE_UINT32,  # 13
+    FieldDescriptorProtoType.TYPE_SFIXED32,  # 15
+    FieldDescriptorProtoType.TYPE_SFIXED64,  # 16
+    FieldDescriptorProtoType.TYPE_SINT32,  # 17
+    FieldDescriptorProtoType.TYPE_SINT64,  # 18
 )
-PROTO_BOOL_TYPES = (FieldDescriptorProto.TYPE_BOOL,)  # 8
-PROTO_STR_TYPES = (FieldDescriptorProto.TYPE_STRING,)  # 9
-PROTO_BYTES_TYPES = (FieldDescriptorProto.TYPE_BYTES,)  # 12
+PROTO_BOOL_TYPES = (FieldDescriptorProtoType.TYPE_BOOL,)  # 8
+PROTO_STR_TYPES = (FieldDescriptorProtoType.TYPE_STRING,)  # 9
+PROTO_BYTES_TYPES = (FieldDescriptorProtoType.TYPE_BYTES,)  # 12
 PROTO_MESSAGE_TYPES = (
-    FieldDescriptorProto.TYPE_MESSAGE,  # 11
-    FieldDescriptorProto.TYPE_ENUM,  # 14
+    FieldDescriptorProtoType.TYPE_MESSAGE,  # 11
+    FieldDescriptorProtoType.TYPE_ENUM,  # 14
 )
-PROTO_MAP_TYPES = (FieldDescriptorProto.TYPE_MESSAGE,)  # 11
+PROTO_MAP_TYPES = (FieldDescriptorProtoType.TYPE_MESSAGE,)  # 11
 PROTO_PACKED_TYPES = (
-    FieldDescriptorProto.TYPE_DOUBLE,  # 1
-    FieldDescriptorProto.TYPE_FLOAT,  # 2
-    FieldDescriptorProto.TYPE_INT64,  # 3
-    FieldDescriptorProto.TYPE_UINT64,  # 4
-    FieldDescriptorProto.TYPE_INT32,  # 5
-    FieldDescriptorProto.TYPE_FIXED64,  # 6
-    FieldDescriptorProto.TYPE_FIXED32,  # 7
-    FieldDescriptorProto.TYPE_BOOL,  # 8
-    FieldDescriptorProto.TYPE_UINT32,  # 13
-    FieldDescriptorProto.TYPE_SFIXED32,  # 15
-    FieldDescriptorProto.TYPE_SFIXED64,  # 16
-    FieldDescriptorProto.TYPE_SINT32,  # 17
-    FieldDescriptorProto.TYPE_SINT64,  # 18
+    FieldDescriptorProtoType.TYPE_DOUBLE,  # 1
+    FieldDescriptorProtoType.TYPE_FLOAT,  # 2
+    FieldDescriptorProtoType.TYPE_INT64,  # 3
+    FieldDescriptorProtoType.TYPE_UINT64,  # 4
+    FieldDescriptorProtoType.TYPE_INT32,  # 5
+    FieldDescriptorProtoType.TYPE_FIXED64,  # 6
+    FieldDescriptorProtoType.TYPE_FIXED32,  # 7
+    FieldDescriptorProtoType.TYPE_BOOL,  # 8
+    FieldDescriptorProtoType.TYPE_UINT32,  # 13
+    FieldDescriptorProtoType.TYPE_SFIXED32,  # 15
+    FieldDescriptorProtoType.TYPE_SFIXED64,  # 16
+    FieldDescriptorProtoType.TYPE_SINT32,  # 17
+    FieldDescriptorProtoType.TYPE_SINT64,  # 18
 )
 
 
+def monkey_patch_oneof_index():
+    """
+    The compiler message types are written for proto2, but we read them as proto3.
+    For this to work in the case of the oneof_index fields, which depend on being able
+    to tell whether they were set, we have to treat them as oneof fields. This method
+    monkey patches the generated classes after the fact to force this behaviour.
+    """
+    object.__setattr__(
+        FieldDescriptorProto.__dataclass_fields__["oneof_index"].metadata[
+            "betterproto"
+        ],
+        "group",
+        "_oneof_index",
+    )
+    object.__setattr__(
+        Field.__dataclass_fields__["oneof_index"].metadata["betterproto"],
+        "group",
+        "_oneof_index",
+    )
+
+
 def get_comment(
     proto_file: "FileDescriptorProto", path: List[int], indent: int = 4
 ) -> str:
     pad = " " * indent
-    for sci in proto_file.source_code_info.location:
-        if list(sci.path) == path and sci.leading_comments:
+    for sci_loc in proto_file.source_code_info.location:
+        if list(sci_loc.path) == path and sci_loc.leading_comments:
             lines = textwrap.wrap(
-                sci.leading_comments.strip().replace("\n", ""), width=79 - indent
+                sci_loc.leading_comments.strip().replace("\n", ""), width=79 - indent
             )
 
-            if path[-2] == 2 and path[-4] != 6:
-                # This is a field
-                return f"{pad}# " + f"\n{pad}# ".join(lines)
+            # This is a field, message, enum, service, or method
+            if len(lines) == 1 and len(lines[0]) < 79 - indent - 6:
+                lines[0] = lines[0].strip('"')
+                return f'{pad}"""{lines[0]}"""'
             else:
-                # This is a message, enum, service, or method
-                if len(lines) == 1 and len(lines[0]) < 79 - indent - 6:
-                    lines[0] = lines[0].strip('"')
-                    return f'{pad}"""{lines[0]}"""'
-                else:
-                    joined = f"\n{pad}".join(lines)
-                    return f'{pad}"""\n{pad}{joined}\n{pad}"""'
+                joined = f"\n{pad}".join(lines)
+                return f'{pad}"""\n{pad}{joined}\n{pad}"""'
 
     return ""
 
@@ -139,10 +175,13 @@ def get_comment(
 class ProtoContentBase:
     """Methods common to MessageCompiler, ServiceCompiler and ServiceMethodCompiler."""
 
+    source_file: FileDescriptorProto
     path: List[int]
     comment_indent: int = 4
     parent: Union["betterproto.Message", "OutputTemplate"]
 
+    __dataclass_fields__: Dict[str, object]
+
     def __post_init__(self) -> None:
         """Checks that no fake default fields were left as placeholders."""
         for field_name, field_val in self.__dataclass_fields__.items():
@@ -156,13 +195,6 @@ class ProtoContentBase:
             current = current.parent
         return current
 
-    @property
-    def proto_file(self) -> FieldDescriptorProto:
-        current = self
-        while not isinstance(current, OutputTemplate):
-            current = current.parent
-        return current.package_proto_obj
-
     @property
     def request(self) -> "PluginRequestCompiler":
         current = self
@@ -176,14 +208,13 @@ class ProtoContentBase:
         for this object.
         """
         return get_comment(
-            proto_file=self.proto_file, path=self.path, indent=self.comment_indent
+            proto_file=self.source_file, path=self.path, indent=self.comment_indent
         )
 
 
 @dataclass
 class PluginRequestCompiler:
-
-    plugin_request_obj: plugin.CodeGeneratorRequest
+    plugin_request_obj: CodeGeneratorRequest
     output_packages: Dict[str, "OutputTemplate"] = field(default_factory=dict)
 
     @property
@@ -215,9 +246,14 @@ class OutputTemplate:
     imports: Set[str] = field(default_factory=set)
     datetime_imports: Set[str] = field(default_factory=set)
     typing_imports: Set[str] = field(default_factory=set)
+    pydantic_imports: Set[str] = field(default_factory=set)
+    builtins_import: bool = False
     messages: List["MessageCompiler"] = field(default_factory=list)
     enums: List["EnumDefinitionCompiler"] = field(default_factory=list)
     services: List["ServiceCompiler"] = field(default_factory=list)
+    imports_type_checking_only: Set[str] = field(default_factory=set)
+    pydantic_dataclasses: bool = False
+    output: bool = True
 
     @property
     def package(self) -> str:
@@ -231,21 +267,23 @@ class OutputTemplate:
         return self.package_proto_obj.package
 
     @property
-    def input_filenames(self) -> List[str]:
+    def input_filenames(self) -> Iterable[str]:
         """Names of the input files used to build this output.
 
         Returns
         -------
-        List[str]
+        Iterable[str]
             Names of the input files used to build this output.
         """
-        return [f.name for f in self.input_files]
+        return sorted(f.name for f in self.input_files)
 
     @property
     def python_module_imports(self) -> Set[str]:
         imports = set()
         if any(x for x in self.messages if any(x.deprecated_fields)):
             imports.add("warnings")
+        if self.builtins_import:
+            imports.add("builtins")
         return imports
 
 
@@ -253,6 +291,7 @@ class OutputTemplate:
 class MessageCompiler(ProtoContentBase):
     """Representation of a protobuf message."""
 
+    source_file: FileDescriptorProto
     parent: Union["MessageCompiler", OutputTemplate] = PLACEHOLDER
     proto_obj: DescriptorProto = PLACEHOLDER
     path: List[int] = PLACEHOLDER
@@ -260,6 +299,7 @@ class MessageCompiler(ProtoContentBase):
         default_factory=list
     )
     deprecated: bool = field(default=False, init=False)
+    builtins_types: Set[str] = field(default_factory=set)
 
     def __post_init__(self) -> None:
         # Add message to output file
@@ -291,12 +331,33 @@ class MessageCompiler(ProtoContentBase):
             if f.deprecated:
                 yield f.py_name
 
+    @property
+    def has_deprecated_fields(self) -> bool:
+        return any(self.deprecated_fields)
+
+    @property
+    def has_oneof_fields(self) -> bool:
+        return any(isinstance(field, OneOfFieldCompiler) for field in self.fields)
+
+    @property
+    def has_message_field(self) -> bool:
+        return any(
+            (
+                field.proto_obj.type in PROTO_MESSAGE_TYPES
+                for field in self.fields
+                if isinstance(field.proto_obj, FieldDescriptorProto)
+            )
+        )
+
 
 def is_map(
     proto_field_obj: FieldDescriptorProto, parent_message: DescriptorProto
 ) -> bool:
     """True if proto_field_obj is a map, otherwise False."""
-    if proto_field_obj.type == FieldDescriptorProto.TYPE_MESSAGE:
+    if proto_field_obj.type == FieldDescriptorProtoType.TYPE_MESSAGE:
+        if not hasattr(parent_message, "nested_type"):
+            return False
+
         # This might be a map...
         message_type = proto_field_obj.type_name.split(".").pop().lower()
         map_entry = f"{proto_field_obj.name.replace('_', '').lower()}entry"
@@ -311,8 +372,20 @@ def is_map(
 
 
 def is_oneof(proto_field_obj: FieldDescriptorProto) -> bool:
-    """True if proto_field_obj is a OneOf, otherwise False."""
-    return proto_field_obj.HasField("oneof_index")
+    """
+    True if proto_field_obj is a OneOf, otherwise False.
+
+    .. warning::
+        Becuase the message from protoc is defined in proto2, and betterproto works with
+        proto3, and interpreting the FieldDescriptorProto.oneof_index field requires
+        distinguishing between default and unset values (which proto3 doesn't support),
+        we have to hack the generated FieldDescriptorProto class for this to work.
+        The hack consists of setting group="oneof_index" in the field metadata,
+        essentially making oneof_index the sole member of a one_of group, which allows
+        us to tell whether it was set, via the which_one_of interface.
+    """
+
+    return which_one_of(proto_field_obj, "_oneof_index")[0] == "oneof_index"
 
 
 @dataclass
@@ -324,17 +397,7 @@ class FieldCompiler(MessageCompiler):
         # Add field to message
         self.parent.fields.append(self)
         # Check for new imports
-        annotation = self.annotation
-        if "Optional[" in annotation:
-            self.output_file.typing_imports.add("Optional")
-        if "List[" in annotation:
-            self.output_file.typing_imports.add("List")
-        if "Dict[" in annotation:
-            self.output_file.typing_imports.add("Dict")
-        if "timedelta" in annotation:
-            self.output_file.datetime_imports.add("timedelta")
-        if "datetime" in annotation:
-            self.output_file.datetime_imports.add("datetime")
+        self.add_imports_to(self.output_file)
         super().__post_init__()  # call FieldCompiler-> MessageCompiler __post_init__
 
     def get_field_string(self, indent: int = 4) -> str:
@@ -347,6 +410,8 @@ class FieldCompiler(MessageCompiler):
         betterproto_field_type = (
             f"betterproto.{self.field_type}_field({self.proto_obj.number}{field_args})"
         )
+        if self.py_name in dir(builtins):
+            self.parent.builtins_types.add(self.py_name)
         return f"{name}{annotations} = {betterproto_field_type}"
 
     @property
@@ -354,13 +419,54 @@ class FieldCompiler(MessageCompiler):
         args = []
         if self.field_wraps:
             args.append(f"wraps={self.field_wraps}")
+        if self.optional:
+            args.append(f"optional=True")
         return args
 
+    @property
+    def datetime_imports(self) -> Set[str]:
+        imports = set()
+        annotation = self.annotation
+        # FIXME: false positives - e.g. `MyDatetimedelta`
+        if "timedelta" in annotation:
+            imports.add("timedelta")
+        if "datetime" in annotation:
+            imports.add("datetime")
+        return imports
+
+    @property
+    def typing_imports(self) -> Set[str]:
+        imports = set()
+        annotation = self.annotation
+        if "Optional[" in annotation:
+            imports.add("Optional")
+        if "List[" in annotation:
+            imports.add("List")
+        if "Dict[" in annotation:
+            imports.add("Dict")
+        return imports
+
+    @property
+    def pydantic_imports(self) -> Set[str]:
+        return set()
+
+    @property
+    def use_builtins(self) -> bool:
+        return self.py_type in self.parent.builtins_types or (
+            self.py_type == self.py_name and self.py_name in dir(builtins)
+        )
+
+    def add_imports_to(self, output_file: OutputTemplate) -> None:
+        output_file.datetime_imports.update(self.datetime_imports)
+        output_file.typing_imports.update(self.typing_imports)
+        output_file.pydantic_imports.update(self.pydantic_imports)
+        output_file.builtins_import = output_file.builtins_import or self.use_builtins
+
     @property
     def field_wraps(self) -> Optional[str]:
         """Returns betterproto wrapped field type or None."""
         match_wrapper = re.match(
-            r"\.google\.protobuf\.(.+)Value", self.proto_obj.type_name
+            r"\.google\.protobuf\.(.+)Value$", self.proto_obj.type_name
         )
         if match_wrapper:
             wrapped_type = "TYPE_" + match_wrapper.group(1).upper()
@@ -371,10 +477,14 @@ class FieldCompiler(MessageCompiler):
     @property
     def repeated(self) -> bool:
         return (
-            self.proto_obj.label == FieldDescriptorProto.LABEL_REPEATED
+            self.proto_obj.label == FieldDescriptorProtoLabel.LABEL_REPEATED
             and not is_map(self.proto_obj, self.parent)
         )
 
+    @property
+    def optional(self) -> bool:
+        return self.proto_obj.proto3_optional
+
     @property
     def mutable(self) -> bool:
         """True if the field is a mutable type, otherwise False."""
@@ -384,14 +494,18 @@ class FieldCompiler(MessageCompiler):
     def field_type(self) -> str:
         """String representation of proto field type."""
         return (
-            self.proto_obj.Type.Name(self.proto_obj.type).lower().replace("type_", "")
+            FieldDescriptorProtoType(self.proto_obj.type)
+            .name.lower()
+            .replace("type_", "")
         )
 
     @property
-    def default_value_string(self) -> Union[Text, None, float, int]:
+    def default_value_string(self) -> str:
         """Python representation of the default proto value."""
         if self.repeated:
             return "[]"
+        if self.optional:
+            return "None"
         if self.py_type == "int":
             return "0"
         if self.py_type == "float":
@@ -402,6 +516,14 @@ class FieldCompiler(MessageCompiler):
             return '""'
         elif self.py_type == "bytes":
             return 'b""'
+        elif self.field_type == "enum":
+            enum_proto_obj_name = self.proto_obj.type_name.split(".").pop()
+            enum = next(
+                e
+                for e in self.output_file.enums
+                if e.proto_obj.name == enum_proto_obj_name
+            )
+            return enum.default_value_string
         else:
             # Message type
             return "None"
@@ -442,13 +564,18 @@ class FieldCompiler(MessageCompiler):
                 source_type=self.proto_obj.type_name,
             )
         else:
-            raise NotImplementedError(f"Unknown type {field.type}")
+            raise NotImplementedError(f"Unknown type {self.proto_obj.type}")
 
     @property
     def annotation(self) -> str:
+        py_type = self.py_type
+        if self.use_builtins:
+            py_type = f"builtins.{py_type}"
         if self.repeated:
-            return f"List[{self.py_type}]"
-        return self.py_type
+            return f"List[{py_type}]"
+        if self.optional:
+            return f"Optional[{py_type}]"
+        return py_type
 
 
 @dataclass
@@ -461,6 +588,20 @@ class OneOfFieldCompiler(FieldCompiler):
         return args
 
 
+@dataclass
+class PydanticOneOfFieldCompiler(OneOfFieldCompiler):
+    @property
+    def optional(self) -> bool:
+        # Force the optional to be True. This will allow the pydantic dataclass
+        # to validate the object correctly by allowing the field to be let empty.
+        # We add a pydantic validator later to ensure exactly one field is defined.
+        return True
+
+    @property
+    def pydantic_imports(self) -> Set[str]:
+        return {"root_validator"}
+
+
 @dataclass
 class MapEntryCompiler(FieldCompiler):
     py_k_type: Type = PLACEHOLDER
@@ -478,14 +619,19 @@ class MapEntryCompiler(FieldCompiler):
             ):
                 # Get Python types
                 self.py_k_type = FieldCompiler(
-                    parent=self, proto_obj=nested.field[0]  # key
+                    source_file=self.source_file,
+                    parent=self,
+                    proto_obj=nested.field[0],  # key
                 ).py_type
                 self.py_v_type = FieldCompiler(
-                    parent=self, proto_obj=nested.field[1]  # value
+                    source_file=self.source_file,
+                    parent=self,
+                    proto_obj=nested.field[1],  # value
                 ).py_type
+
                 # Get proto types
-                self.proto_k_type = self.proto_obj.Type.Name(nested.field[0].type)
-                self.proto_v_type = self.proto_obj.Type.Name(nested.field[1].type)
+                self.proto_k_type = FieldDescriptorProtoType(nested.field[0].type).name
+                self.proto_v_type = FieldDescriptorProtoType(nested.field[1].type).name
         super().__post_init__()  # call FieldCompiler-> MessageCompiler __post_init__
 
     @property
@@ -527,7 +673,7 @@ class EnumDefinitionCompiler(MessageCompiler):
                 name=sanitize_name(entry_proto_value.name),
                 value=entry_proto_value.number,
                 comment=get_comment(
-                    proto_file=self.proto_file, path=self.path + [2, entry_number]
+                    proto_file=self.source_file, path=self.path + [2, entry_number]
                 ),
             )
             for entry_number, entry_proto_value in enumerate(self.proto_obj.value)
@@ -553,6 +699,7 @@ class ServiceCompiler(ProtoContentBase):
     def __post_init__(self) -> None:
         # Add service to output file
         self.output_file.services.append(self)
+        self.output_file.typing_imports.add("Dict")
         super().__post_init__()  # check for unset fields
 
     @property
@@ -566,7 +713,6 @@ class ServiceCompiler(ProtoContentBase):
 
 @dataclass
 class ServiceMethodCompiler(ProtoContentBase):
-
     parent: ServiceCompiler
     proto_obj: MethodDescriptorProto
     path: List[int] = PLACEHOLDER
@@ -576,56 +722,32 @@ class ServiceMethodCompiler(ProtoContentBase):
         # Add method to service
         self.parent.methods.append(self)
 
-        # Check for Optional import
-        if self.py_input_message:
-            for f in self.py_input_message.fields:
-                if f.default_value_string == "None":
-                    self.output_file.typing_imports.add("Optional")
+        # Check for imports
         if "Optional" in self.py_output_message_type:
             self.output_file.typing_imports.add("Optional")
-        self.mutable_default_args  # ensure this is called before rendering
 
         # Check for Async imports
         if self.client_streaming:
             self.output_file.typing_imports.add("AsyncIterable")
             self.output_file.typing_imports.add("Iterable")
             self.output_file.typing_imports.add("Union")
-        if self.server_streaming:
+
+        # Required by both client and server
+        if self.client_streaming or self.server_streaming:
             self.output_file.typing_imports.add("AsyncIterator")
 
+        # add imports required for request arguments timeout, deadline and metadata
+        self.output_file.typing_imports.add("Optional")
+        self.output_file.imports_type_checking_only.add("import grpclib.server")
+        self.output_file.imports_type_checking_only.add(
+            "from betterproto.grpc.grpclib_client import MetadataLike"
+        )
+        self.output_file.imports_type_checking_only.add(
+            "from grpclib.metadata import Deadline"
+        )
+
         super().__post_init__()  # check for unset fields
 
-    @property
-    def mutable_default_args(self) -> Dict[str, str]:
-        """Handle mutable default arguments.
-
-        Returns a list of tuples containing the name and default value
-        for arguments to this message who's default value is mutable.
-        The defaults are swapped out for None and replaced back inside
-        the method's body.
-        Reference:
-        https://docs.python-guide.org/writing/gotchas/#mutable-default-arguments
-
-        Returns
-        -------
-        Dict[str, str]
-            Name and actual default value (as a string)
-            for each argument with mutable default values.
-        """
-        mutable_default_args = {}
-
-        if self.py_input_message:
-            for f in self.py_input_message.fields:
-                if (
-                    not self.client_streaming
-                    and f.default_value_string != "None"
-                    and f.mutable
-                ):
-                    mutable_default_args[f.py_name] = f.default_value_string
-                    self.output_file.typing_imports.add("Optional")
-
-        return mutable_default_args
-
     @property
     def py_name(self) -> str:
         """Pythonized method name."""
@@ -638,7 +760,10 @@ class ServiceMethodCompiler(ProtoContentBase):
 
     @property
     def route(self) -> str:
-        return f"/{self.output_file.package}.{self.parent.proto_name}/{self.proto_name}"
+        package_part = (
+            f"{self.output_file.package}." if self.output_file.package else ""
+        )
+        return f"/{package_part}{self.parent.proto_name}/{self.proto_name}"
 
     @property
     def py_input_message(self) -> Optional[MessageCompiler]:
@@ -658,7 +783,7 @@ class ServiceMethodCompiler(ProtoContentBase):
         # comparable with method.input_type
         for msg in self.request.all_messages:
             if (
-                msg.py_name == name.replace(".", "")
+                msg.py_name == pythonize_class_name(name.replace(".", ""))
                 and msg.output_file.package == package
             ):
                 return msg
@@ -678,8 +803,20 @@ class ServiceMethodCompiler(ProtoContentBase):
             package=self.output_file.package,
             imports=self.output_file.imports,
             source_type=self.proto_obj.input_type,
+            unwrap=False,
         ).strip('"')
 
+    @property
+    def py_input_message_param(self) -> str:
+        """Param name corresponding to py_input_message_type.
+
+        Returns
+        -------
+        str
+            Param name corresponding to py_input_message_type.
+        """
+        return pythonize_field_name(self.py_input_message_type)
+
     @property
     def py_output_message_type(self) -> str:
         """String representation of the Python type corresponding to the

src/betterproto/plugin/parser.py

@@ -1,27 +1,26 @@
-import itertools
 import pathlib
 import sys
-from typing import TYPE_CHECKING, Iterator, List, Tuple, Union, Set
+from typing import (
+    Generator,
+    List,
+    Set,
+    Tuple,
+    Union,
+)
 
-try:
-    # betterproto[compiler] specific dependencies
-    from google.protobuf.compiler import plugin_pb2 as plugin
-    from google.protobuf.descriptor_pb2 import (
-        DescriptorProto,
-        EnumDescriptorProto,
-        FieldDescriptorProto,
-        ServiceDescriptorProto,
-    )
-except ImportError as err:
-    print(
-        "\033[31m"
-        f"Unable to import `{err.name}` from betterproto plugin! "
-        "Please ensure that you've installed betterproto as "
-        '`pip install "betterproto[compiler]"` so that compiler dependencies '
-        "are included."
-        "\033[0m"
-    )
-    raise SystemExit(1)
+from betterproto.lib.google.protobuf import (
+    DescriptorProto,
+    EnumDescriptorProto,
+    FieldDescriptorProto,
+    FileDescriptorProto,
+    ServiceDescriptorProto,
+)
+from betterproto.lib.google.protobuf.compiler import (
+    CodeGeneratorRequest,
+    CodeGeneratorResponse,
+    CodeGeneratorResponseFeature,
+    CodeGeneratorResponseFile,
+)
 
 from .compiler import outputfile_compiler
 from .models import (
@@ -32,59 +31,51 @@ from .models import (
     OneOfFieldCompiler,
     OutputTemplate,
     PluginRequestCompiler,
+    PydanticOneOfFieldCompiler,
     ServiceCompiler,
     ServiceMethodCompiler,
     is_map,
     is_oneof,
 )
 
-if TYPE_CHECKING:
-    from google.protobuf.descriptor import Descriptor
-
 
 def traverse(
-    proto_file: FieldDescriptorProto,
-) -> "itertools.chain[Tuple[Union[str, EnumDescriptorProto], List[int]]]":
+    proto_file: FileDescriptorProto,
+) -> Generator[
+    Tuple[Union[EnumDescriptorProto, DescriptorProto], List[int]], None, None
+]:
     # Todo: Keep information about nested hierarchy
     def _traverse(
-        path: List[int], items: List["Descriptor"], prefix=""
-    ) -> Iterator[Tuple[Union[str, EnumDescriptorProto], List[int]]]:
+        path: List[int],
+        items: Union[List[EnumDescriptorProto], List[DescriptorProto]],
+        prefix: str = "",
+    ) -> Generator[
+        Tuple[Union[EnumDescriptorProto, DescriptorProto], List[int]], None, None
+    ]:
         for i, item in enumerate(items):
             # Adjust the name since we flatten the hierarchy.
             # Todo: don't change the name, but include full name in returned tuple
-            item.name = next_prefix = prefix + item.name
-            yield item, path + [i]
+            item.name = next_prefix = f"{prefix}_{item.name}"
+            yield item, [*path, i]
 
             if isinstance(item, DescriptorProto):
-                for enum in item.enum_type:
-                    enum.name = next_prefix + enum.name
-                    yield enum, path + [i, 4]
+                # Get nested types.
+                yield from _traverse([*path, i, 4], item.enum_type, next_prefix)
+                yield from _traverse([*path, i, 3], item.nested_type, next_prefix)
 
-                if item.nested_type:
-                    for n, p in _traverse(path + [i, 3], item.nested_type, next_prefix):
-                        yield n, p
-
-    return itertools.chain(
-        _traverse([5], proto_file.enum_type), _traverse([4], proto_file.message_type)
-    )
+    yield from _traverse([5], proto_file.enum_type)
+    yield from _traverse([4], proto_file.message_type)
 
 
-def generate_code(
-    request: plugin.CodeGeneratorRequest, response: plugin.CodeGeneratorResponse
-) -> None:
+def generate_code(request: CodeGeneratorRequest) -> CodeGeneratorResponse:
+    response = CodeGeneratorResponse()
+
     plugin_options = request.parameter.split(",") if request.parameter else []
+    response.supported_features = CodeGeneratorResponseFeature.FEATURE_PROTO3_OPTIONAL
 
     request_data = PluginRequestCompiler(plugin_request_obj=request)
     # Gather output packages
     for proto_file in request.proto_file:
-        if (
-            proto_file.package == "google.protobuf"
-            and "INCLUDE_GOOGLE" not in plugin_options
-        ):
-            # If not INCLUDE_GOOGLE,
-            # skip re-compiling Google's well-known types
-            continue
-
         output_package_name = proto_file.package
         if output_package_name not in request_data.output_packages:
             # Create a new output if there is no output for this package
@@ -94,13 +85,31 @@ def generate_code(
         # Add this input file to the output corresponding to this package
         request_data.output_packages[output_package_name].input_files.append(proto_file)
 
+        if (
+            proto_file.package == "google.protobuf"
+            and "INCLUDE_GOOGLE" not in plugin_options
+        ):
+            # If not INCLUDE_GOOGLE,
+            # skip outputting Google's well-known types
+            request_data.output_packages[output_package_name].output = False
+
+        if "pydantic_dataclasses" in plugin_options:
+            request_data.output_packages[
+                output_package_name
+            ].pydantic_dataclasses = True
+
     # Read Messages and Enums
     # We need to read Messages before Services in so that we can
     # get the references to input/output messages for each service
     for output_package_name, output_package in request_data.output_packages.items():
         for proto_input_file in output_package.input_files:
             for item, path in traverse(proto_input_file):
-                read_protobuf_type(item=item, path=path, output_package=output_package)
+                read_protobuf_type(
+                    source_file=proto_input_file,
+                    item=item,
+                    path=path,
+                    output_package=output_package,
+                )
 
     # Read Services
     for output_package_name, output_package in request_data.output_packages.items():
@@ -111,57 +120,93 @@ def generate_code(
     # Generate output files
     output_paths: Set[pathlib.Path] = set()
     for output_package_name, output_package in request_data.output_packages.items():
+        if not output_package.output:
+            continue
 
         # Add files to the response object
         output_path = pathlib.Path(*output_package_name.split("."), "__init__.py")
         output_paths.add(output_path)
 
-        f: response.File = response.file.add()
-        f.name = str(output_path)
-
-        # Render and then format the output file
-        f.content = outputfile_compiler(output_file=output_package)
+        response.file.append(
+            CodeGeneratorResponseFile(
+                name=str(output_path),
+                # Render and then format the output file
+                content=outputfile_compiler(output_file=output_package),
+            )
+        )
 
     # Make each output directory a package with __init__ file
     init_files = {
         directory.joinpath("__init__.py")
         for path in output_paths
         for directory in path.parents
+        if not directory.joinpath("__init__.py").exists()
     } - output_paths
 
     for init_file in init_files:
-        init = response.file.add()
-        init.name = str(init_file)
+        response.file.append(CodeGeneratorResponseFile(name=str(init_file)))
 
     for output_package_name in sorted(output_paths.union(init_files)):
         print(f"Writing {output_package_name}", file=sys.stderr)
 
+    return response
+
+
+def _make_one_of_field_compiler(
+    output_package: OutputTemplate,
+    source_file: "FileDescriptorProto",
+    parent: MessageCompiler,
+    proto_obj: "FieldDescriptorProto",
+    path: List[int],
+) -> FieldCompiler:
+    pydantic = output_package.pydantic_dataclasses
+    Cls = PydanticOneOfFieldCompiler if pydantic else OneOfFieldCompiler
+    return Cls(
+        source_file=source_file,
+        parent=parent,
+        proto_obj=proto_obj,
+        path=path,
+    )
+
 
 def read_protobuf_type(
-    item: DescriptorProto, path: List[int], output_package: OutputTemplate
+    item: DescriptorProto,
+    path: List[int],
+    source_file: "FileDescriptorProto",
+    output_package: OutputTemplate,
 ) -> None:
     if isinstance(item, DescriptorProto):
         if item.options.map_entry:
             # Skip generated map entry messages since we just use dicts
             return
         # Process Message
-        message_data = MessageCompiler(parent=output_package, proto_obj=item, path=path)
+        message_data = MessageCompiler(
+            source_file=source_file, parent=output_package, proto_obj=item, path=path
+        )
         for index, field in enumerate(item.field):
             if is_map(field, item):
                 MapEntryCompiler(
-                    parent=message_data, proto_obj=field, path=path + [2, index]
+                    source_file=source_file,
+                    parent=message_data,
+                    proto_obj=field,
+                    path=path + [2, index],
                 )
             elif is_oneof(field):
-                OneOfFieldCompiler(
-                    parent=message_data, proto_obj=field, path=path + [2, index]
+                _make_one_of_field_compiler(
+                    output_package, source_file, message_data, field, path + [2, index]
                 )
             else:
                 FieldCompiler(
-                    parent=message_data, proto_obj=field, path=path + [2, index]
+                    source_file=source_file,
+                    parent=message_data,
+                    proto_obj=field,
+                    path=path + [2, index],
                 )
     elif isinstance(item, EnumDescriptorProto):
         # Enum
-        EnumDefinitionCompiler(parent=output_package, proto_obj=item, path=path)
+        EnumDefinitionCompiler(
+            source_file=source_file, parent=output_package, proto_obj=item, path=path
+        )
 
 
 def read_protobuf_service(

src/betterproto/templates/template.py.j2

@@ -1,10 +1,21 @@
 # Generated by the protocol buffer compiler.  DO NOT EDIT!
 # sources: {{ ', '.join(output_file.input_filenames) }}
 # plugin: python-betterproto
+# This file has been @generated
 {% for i in output_file.python_module_imports|sort %}
 import {{ i }}
 {% endfor %}
+
+{% if output_file.pydantic_dataclasses %}
+from typing import TYPE_CHECKING
+if TYPE_CHECKING:
+    from dataclasses import dataclass
+else:
+    from pydantic.dataclasses import dataclass
+{%- else -%}
 from dataclasses import dataclass
+{% endif %}
+
 {% if output_file.datetime_imports %}
 from datetime import {% for i in output_file.datetime_imports|sort %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
 
@@ -14,11 +25,28 @@ from typing import {% for i in output_file.typing_imports|sort %}{{ i }}{% if no
 
 {% endif %}
 
+{% if output_file.pydantic_imports %}
+from pydantic import {% for i in output_file.pydantic_imports|sort %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
+
+{% endif %}
+
 import betterproto
 {% if output_file.services %}
+from betterproto.grpc.grpclib_server import ServiceBase
 import grpclib
 {% endif %}
 
+{% for i in output_file.imports|sort %}
+{{ i }}
+{% endfor %}
+
+{% if output_file.imports_type_checking_only %}
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+{% for i in output_file.imports_type_checking_only|sort %}    {{ i }}
+{% endfor %}
+{% endif %}
 
 {% if output_file.enums %}{% for enum in output_file.enums %}
 class {{ enum.py_name }}(betterproto.Enum):
@@ -27,10 +55,11 @@ class {{ enum.py_name }}(betterproto.Enum):
 
     {% endif %}
     {% for entry in enum.entries %}
+    {{ entry.name }} = {{ entry.value }}
         {% if entry.comment %}
 {{ entry.comment }}
+
         {% endif %}
-    {{ entry.name }} = {{ entry.value }}
     {% endfor %}
 
 
@@ -44,27 +73,33 @@ class {{ message.py_name }}(betterproto.Message):
 
     {% endif %}
     {% for field in message.fields %}
+    {{ field.get_field_string() }}
         {% if field.comment %}
 {{ field.comment }}
+
         {% endif %}
-    {{ field.get_field_string() }}
     {% endfor %}
     {% if not message.fields %}
     pass
     {% endif %}
 
-    {% if message.deprecated or message.deprecated_fields %}
+    {% if message.deprecated or message.has_deprecated_fields %}
     def __post_init__(self) -> None:
         {% if message.deprecated %}
         warnings.warn("{{ message.py_name }} is deprecated", DeprecationWarning)
         {% endif %}
         super().__post_init__()
         {% for field in message.deprecated_fields %}
-        if self.{{ field }}:
+        if self.is_set("{{ field }}"):
             warnings.warn("{{ message.py_name }}.{{ field }} is deprecated", DeprecationWarning)
         {% endfor %}
     {%  endif %}
 
+    {% if output_file.pydantic_dataclasses and message.has_oneof_fields %}
+    @root_validator()
+    def check_oneof(cls, values):
+        return cls._validate_field_groups(values)
+    {%  endif %}
 
 {% endfor %}
 {% for service in output_file.services %}
@@ -72,64 +107,47 @@ class {{ service.py_name }}Stub(betterproto.ServiceStub):
     {% if service.comment %}
 {{ service.comment }}
 
+    {% elif not service.methods %}
+    pass
     {% endif %}
     {% for method in service.methods %}
     async def {{ method.py_name }}(self
         {%- if not method.client_streaming -%}
-            {%- if method.py_input_message and method.py_input_message.fields -%}, *,
-                {%- for field in method.py_input_message.fields -%}
-                    {{ field.py_name }}: {% if field.py_name in method.mutable_default_args and not field.annotation.startswith("Optional[") -%}
-                                            Optional[{{ field.annotation }}]
-                                         {%- else -%}
-                                            {{ field.annotation }}
-                                         {%- endif -%} = 
-                                            {%- if field.py_name not in method.mutable_default_args -%}
-                                                {{ field.default_value_string }}
-                                            {%- else -%}
-                                                None
-                                            {% endif -%}
-                    {%- if not loop.last %}, {% endif -%}
-                {%- endfor -%}
-            {%- endif -%}
+            {%- if method.py_input_message -%}, {{ method.py_input_message_param }}: "{{ method.py_input_message_type }}"{%- endif -%}
         {%- else -%}
             {# Client streaming: need a request iterator instead #}
-            , request_iterator: Union[AsyncIterable["{{ method.py_input_message_type }}"], Iterable["{{ method.py_input_message_type }}"]]
+            , {{ method.py_input_message_param }}_iterator: Union[AsyncIterable["{{ method.py_input_message_type }}"], Iterable["{{ method.py_input_message_type }}"]]
         {%- endif -%}
+            ,
+            *
+            , timeout: Optional[float] = None
+            , deadline: Optional["Deadline"] = None
+            , metadata: Optional["MetadataLike"] = None
             ) -> {% if method.server_streaming %}AsyncIterator["{{ method.py_output_message_type }}"]{% else %}"{{ method.py_output_message_type }}"{% endif %}:
         {% if method.comment %}
 {{ method.comment }}
 
         {% endif %}
-        {%- for py_name, zero in method.mutable_default_args.items() %}
-        {{ py_name }} = {{ py_name }} or {{ zero }}
-        {% endfor %}
-
-        {% if not method.client_streaming %}
-        request = {{ method.py_input_message_type }}()
-        {% for field in method.py_input_message.fields %}
-            {% if field.field_type == 'message' %}
-        if {{ field.py_name }} is not None:
-            request.{{ field.py_name }} = {{ field.py_name }}
-            {% else %}
-        request.{{ field.py_name }} = {{ field.py_name }}
-            {% endif %}
-        {% endfor %}
-        {% endif %}
-
         {% if method.server_streaming %}
             {% if method.client_streaming %}
         async for response in self._stream_stream(
             "{{ method.route }}",
-            request_iterator,
+            {{ method.py_input_message_param }}_iterator,
             {{ method.py_input_message_type }},
             {{ method.py_output_message_type.strip('"') }},
+            timeout=timeout,
+            deadline=deadline,
+            metadata=metadata,
         ):
             yield response
             {% else %}{# i.e. not client streaming #}
         async for response in self._unary_stream(
             "{{ method.route }}",
-            request,
+            {{ method.py_input_message_param }},
             {{ method.py_output_message_type.strip('"') }},
+            timeout=timeout,
+            deadline=deadline,
+            metadata=metadata,
         ):
             yield response
 
@@ -138,15 +156,21 @@ class {{ service.py_name }}Stub(betterproto.ServiceStub):
             {% if method.client_streaming %}
         return await self._stream_unary(
             "{{ method.route }}",
-            request_iterator,
+            {{ method.py_input_message_param }}_iterator,
             {{ method.py_input_message_type }},
-            {{ method.py_output_message_type.strip('"') }}
+            {{ method.py_output_message_type.strip('"') }},
+            timeout=timeout,
+            deadline=deadline,
+            metadata=metadata,
         )
             {% else %}{# i.e. not client streaming #}
         return await self._unary_unary(
             "{{ method.route }}",
-            request,
-            {{ method.py_output_message_type.strip('"') }}
+            {{ method.py_input_message_param }},
+            {{ method.py_output_message_type.strip('"') }},
+            timeout=timeout,
+            deadline=deadline,
+            metadata=metadata,
         )
             {% endif %}{# client streaming #}
         {% endif %}
@@ -154,6 +178,79 @@ class {{ service.py_name }}Stub(betterproto.ServiceStub):
     {% endfor %}
 {% endfor %}
 
-{% for i in output_file.imports|sort %}
-{{ i }}
+{% for service in output_file.services %}
+class {{ service.py_name }}Base(ServiceBase):
+    {% if service.comment %}
+{{ service.comment }}
+
+    {% endif %}
+
+    {% for method in service.methods %}
+    async def {{ method.py_name }}(self
+        {%- if not method.client_streaming -%}
+            {%- if method.py_input_message -%}, {{ method.py_input_message_param }}: "{{ method.py_input_message_type }}"{%- endif -%}
+        {%- else -%}
+            {# Client streaming: need a request iterator instead #}
+            , {{ method.py_input_message_param }}_iterator: AsyncIterator["{{ method.py_input_message_type }}"]
+        {%- endif -%}
+            ) -> {% if method.server_streaming %}AsyncIterator["{{ method.py_output_message_type }}"]{% else %}"{{ method.py_output_message_type }}"{% endif %}:
+        {% if method.comment %}
+{{ method.comment }}
+
+        {% endif %}
+        raise grpclib.GRPCError(grpclib.const.Status.UNIMPLEMENTED)
+        {% if method.server_streaming %}
+        yield {{ method.py_output_message_type }}()
+        {% endif %}
+
+    {% endfor %}
+
+    {% for method in service.methods %}
+    async def __rpc_{{ method.py_name }}(self, stream: "grpclib.server.Stream[{{ method.py_input_message_type }}, {{ method.py_output_message_type }}]") -> None:
+        {% if not method.client_streaming %}
+        request = await stream.recv_message()
+        {% else %}
+        request = stream.__aiter__()
+        {% endif %}
+        {% if not method.server_streaming %}
+        response = await self.{{ method.py_name }}(request)
+        await stream.send_message(response)
+        {% else %}
+        await self._call_rpc_handler_server_stream(
+            self.{{ method.py_name }},
+            stream,
+            request,
+        )
+        {% endif %}
+
+    {% endfor %}
+
+    def __mapping__(self) -> Dict[str, grpclib.const.Handler]:
+        return {
+        {% for method in service.methods %}
+        "{{ method.route }}": grpclib.const.Handler(
+            self.__rpc_{{ method.py_name }},
+            {% if not method.client_streaming and not method.server_streaming %}
+            grpclib.const.Cardinality.UNARY_UNARY,
+            {% elif not method.client_streaming and method.server_streaming %}
+            grpclib.const.Cardinality.UNARY_STREAM,
+            {% elif method.client_streaming and not method.server_streaming %}
+            grpclib.const.Cardinality.STREAM_UNARY,
+            {% else %}
+            grpclib.const.Cardinality.STREAM_STREAM,
+            {% endif %}
+            {{ method.py_input_message_type }},
+            {{ method.py_output_message_type }},
+        ),
+        {% endfor %}
+        }
+
 {% endfor %}
+
+{% if output_file.pydantic_dataclasses %}
+{% for message in output_file.messages %}
+{% if message.has_message_field %}
+{{ message.py_name }}.__pydantic_model__.update_forward_refs()  # type: ignore
+{% endif %}
+{% endfor %}
+{% endif %}

tests/conftest.py

@@ -1,3 +1,6 @@
+import copy
+import sys
+
 import pytest
 
 
@@ -10,3 +13,10 @@ def pytest_addoption(parser):
 @pytest.fixture(scope="session")
 def repeat(request):
     return request.config.getoption("repeat")
+
+
+@pytest.fixture
+def reset_sys_path():
+    original = copy.deepcopy(sys.path)
+    yield
+    sys.path = original

tests/generate.py

@@ -1,20 +1,22 @@
 #!/usr/bin/env python
 import asyncio
 import os
-from pathlib import Path
 import platform
 import shutil
 import sys
+from pathlib import Path
 from typing import Set
 
 from tests.util import (
     get_directories,
     inputs_path,
     output_path_betterproto,
+    output_path_betterproto_pydantic,
     output_path_reference,
     protoc,
 )
 
+
 # Force pure-python implementation instead of C++, otherwise imports
 # break things because we can't properly reset the symbol database.
 os.environ["PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION"] = "python"
@@ -60,13 +62,15 @@ async def generate(whitelist: Set[str], verbose: bool):
         if result != 0:
             failed_test_cases.append(test_case_name)
 
-    if failed_test_cases:
+    if len(failed_test_cases) > 0:
         sys.stderr.write(
             "\n\033[31;1;4mFailed to generate the following test cases:\033[0m\n"
         )
         for failed_test_case in failed_test_cases:
             sys.stderr.write(f"- {failed_test_case}\n")
 
+        sys.exit(1)
+
 
 async def generate_test_case_output(
     test_case_input_path: Path, test_case_name: str, verbose: bool
@@ -76,10 +80,12 @@ async def generate_test_case_output(
     """
 
     test_case_output_path_reference = output_path_reference.joinpath(test_case_name)
-    test_case_output_path_betterproto = output_path_betterproto.joinpath(test_case_name)
+    test_case_output_path_betterproto = output_path_betterproto
+    test_case_output_path_betterproto_pyd = output_path_betterproto_pydantic
 
     os.makedirs(test_case_output_path_reference, exist_ok=True)
     os.makedirs(test_case_output_path_betterproto, exist_ok=True)
+    os.makedirs(test_case_output_path_betterproto_pyd, exist_ok=True)
 
     clear_directory(test_case_output_path_reference)
     clear_directory(test_case_output_path_betterproto)
@@ -87,28 +93,72 @@ async def generate_test_case_output(
     (
         (ref_out, ref_err, ref_code),
         (plg_out, plg_err, plg_code),
+        (plg_out_pyd, plg_err_pyd, plg_code_pyd),
     ) = await asyncio.gather(
         protoc(test_case_input_path, test_case_output_path_reference, True),
         protoc(test_case_input_path, test_case_output_path_betterproto, False),
+        protoc(
+            test_case_input_path, test_case_output_path_betterproto_pyd, False, True
+        ),
     )
 
-    message = f"Generated output for {test_case_name!r}"
-    if verbose:
-        print(f"\033[31;1;4m{message}\033[0m")
-        if ref_out:
-            sys.stdout.buffer.write(ref_out)
-        if ref_err:
-            sys.stderr.buffer.write(ref_err)
-        if plg_out:
-            sys.stdout.buffer.write(plg_out)
-        if plg_err:
-            sys.stderr.buffer.write(plg_err)
-        sys.stdout.buffer.flush()
-        sys.stderr.buffer.flush()
+    if ref_code == 0:
+        print(f"\033[31;1;4mGenerated reference output for {test_case_name!r}\033[0m")
     else:
-        print(message)
+        print(
+            f"\033[31;1;4mFailed to generate reference output for {test_case_name!r}\033[0m"
+        )
 
-    return max(ref_code, plg_code)
+    if verbose:
+        if ref_out:
+            print("Reference stdout:")
+            sys.stdout.buffer.write(ref_out)
+            sys.stdout.buffer.flush()
+
+        if ref_err:
+            print("Reference stderr:")
+            sys.stderr.buffer.write(ref_err)
+            sys.stderr.buffer.flush()
+
+    if plg_code == 0:
+        print(f"\033[31;1;4mGenerated plugin output for {test_case_name!r}\033[0m")
+    else:
+        print(
+            f"\033[31;1;4mFailed to generate plugin output for {test_case_name!r}\033[0m"
+        )
+
+    if verbose:
+        if plg_out:
+            print("Plugin stdout:")
+            sys.stdout.buffer.write(plg_out)
+            sys.stdout.buffer.flush()
+
+        if plg_err:
+            print("Plugin stderr:")
+            sys.stderr.buffer.write(plg_err)
+            sys.stderr.buffer.flush()
+
+    if plg_code_pyd == 0:
+        print(
+            f"\033[31;1;4mGenerated plugin (pydantic compatible) output for {test_case_name!r}\033[0m"
+        )
+    else:
+        print(
+            f"\033[31;1;4mFailed to generate plugin (pydantic compatible) output for {test_case_name!r}\033[0m"
+        )
+
+    if verbose:
+        if plg_out_pyd:
+            print("Plugin stdout:")
+            sys.stdout.buffer.write(plg_out_pyd)
+            sys.stdout.buffer.flush()
+
+        if plg_err_pyd:
+            print("Plugin stderr:")
+            sys.stderr.buffer.write(plg_err_pyd)
+            sys.stderr.buffer.flush()
+
+    return max(ref_code, plg_code, plg_code_pyd)
 
 
 HELP = "\n".join(
@@ -137,9 +187,19 @@ def main():
         whitelist = set(sys.argv[1:])
 
     if platform.system() == "Windows":
-        asyncio.set_event_loop(asyncio.ProactorEventLoop())
+        # for python version prior to 3.8, loop policy needs to be set explicitly
+        # https://docs.python.org/3/library/asyncio-policy.html#asyncio.DefaultEventLoopPolicy
+        try:
+            asyncio.set_event_loop_policy(asyncio.WindowsProactorEventLoopPolicy())
+        except AttributeError:
+            # python < 3.7 does not have asyncio.WindowsProactorEventLoopPolicy
+            asyncio.get_event_loop_policy().set_event_loop(asyncio.ProactorEventLoop())
 
-    asyncio.get_event_loop().run_until_complete(generate(whitelist, verbose))
+    try:
+        asyncio.run(generate(whitelist, verbose))
+    except AttributeError:
+        # compatibility code for python < 3.7
+        asyncio.get_event_loop().run_until_complete(generate(whitelist, verbose))
 
 
 if __name__ == "__main__":

tests/grpc/test_grpclib_client.py

@@ -1,23 +1,27 @@
 import asyncio
 import sys
+import uuid
 
-from tests.output_betterproto.service.service import (
+import grpclib
+import grpclib.client
+import grpclib.metadata
+import grpclib.server
+import pytest
+from grpclib.testing import ChannelFor
+
+from betterproto.grpc.util.async_channel import AsyncChannel
+from tests.output_betterproto.service import (
     DoThingRequest,
     DoThingResponse,
     GetThingRequest,
     TestStub as ThingServiceClient,
 )
-import grpclib
-import grpclib.metadata
-import grpclib.server
-from grpclib.testing import ChannelFor
-import pytest
-from betterproto.grpc.util.async_channel import AsyncChannel
+
 from .thing_service import ThingService
 
 
-async def _test_client(client, name="clean room", **kwargs):
-    response = await client.do_thing(name=name)
+async def _test_client(client: ThingServiceClient, name="clean room", **kwargs):
+    response = await client.do_thing(DoThingRequest(name=name), **kwargs)
     assert response.names == [name]
 
 
@@ -62,7 +66,7 @@ async def test_trailer_only_error_unary_unary(
     )
     async with ChannelFor([service]) as channel:
         with pytest.raises(grpclib.exceptions.GRPCError) as e:
-            await ThingServiceClient(channel).do_thing(name="something")
+            await ThingServiceClient(channel).do_thing(DoThingRequest(name="something"))
         assert e.value.status == grpclib.Status.UNAUTHENTICATED
 
 
@@ -80,7 +84,7 @@ async def test_trailer_only_error_stream_unary(
     async with ChannelFor([service]) as channel:
         with pytest.raises(grpclib.exceptions.GRPCError) as e:
             await ThingServiceClient(channel).do_many_things(
-                request_iterator=[DoThingRequest(name="something")]
+                do_thing_request_iterator=[DoThingRequest(name="something")]
             )
             await _test_client(ThingServiceClient(channel))
         assert e.value.status == grpclib.Status.UNAUTHENTICATED
@@ -171,6 +175,56 @@ async def test_service_call_lower_level_with_overrides():
         assert response.names == [THING_TO_DO]
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    ("overrides_gen",),
+    [
+        (lambda: dict(timeout=10),),
+        (lambda: dict(deadline=grpclib.metadata.Deadline.from_timeout(10)),),
+        (lambda: dict(metadata={"authorization": str(uuid.uuid4())}),),
+        (lambda: dict(timeout=20, metadata={"authorization": str(uuid.uuid4())}),),
+    ],
+)
+async def test_service_call_high_level_with_overrides(mocker, overrides_gen):
+    overrides = overrides_gen()
+    request_spy = mocker.spy(grpclib.client.Channel, "request")
+    name = str(uuid.uuid4())
+    defaults = dict(
+        timeout=99,
+        deadline=grpclib.metadata.Deadline.from_timeout(99),
+        metadata={"authorization": name},
+    )
+
+    async with ChannelFor(
+        [
+            ThingService(
+                test_hook=_assert_request_meta_received(
+                    deadline=grpclib.metadata.Deadline.from_timeout(
+                        overrides.get("timeout", 99)
+                    ),
+                    metadata=overrides.get("metadata", defaults.get("metadata")),
+                )
+            )
+        ]
+    ) as channel:
+        client = ThingServiceClient(channel, **defaults)
+        await _test_client(client, name=name, **overrides)
+        assert request_spy.call_count == 1
+
+        # for python <3.8 request_spy.call_args.kwargs do not work
+        _, request_spy_call_kwargs = request_spy.call_args_list[0]
+
+        # ensure all overrides were successful
+        for key, value in overrides.items():
+            assert key in request_spy_call_kwargs
+            assert request_spy_call_kwargs[key] == value
+
+        # ensure default values were retained
+        for key in set(defaults.keys()) - set(overrides.keys()):
+            assert key in request_spy_call_kwargs
+            assert request_spy_call_kwargs[key] == defaults[key]
+
+
 @pytest.mark.asyncio
 async def test_async_gen_for_unary_stream_request():
     thing_name = "my milkshakes"
@@ -178,7 +232,9 @@ async def test_async_gen_for_unary_stream_request():
     async with ChannelFor([ThingService()]) as channel:
         client = ThingServiceClient(channel)
         expected_versions = [5, 4, 3, 2, 1]
-        async for response in client.get_thing_versions(name=thing_name):
+        async for response in client.get_thing_versions(
+            GetThingRequest(name=thing_name)
+        ):
             assert response.name == thing_name
             assert response.version == expected_versions.pop()
 

tests/grpc/test_stream_stream.py

@@ -1,9 +1,11 @@
 import asyncio
+from dataclasses import dataclass
+from typing import AsyncIterator
+
+import pytest
+
 import betterproto
 from betterproto.grpc.util.async_channel import AsyncChannel
-from dataclasses import dataclass
-import pytest
-from typing import AsyncIterator
 
 
 @dataclass

tests/grpc/thing_service.py

@@ -1,12 +1,14 @@
-from tests.output_betterproto.service.service import (
-    DoThingResponse,
+from typing import Dict
+
+import grpclib
+import grpclib.server
+
+from tests.output_betterproto.service import (
     DoThingRequest,
+    DoThingResponse,
     GetThingRequest,
     GetThingResponse,
 )
-import grpclib
-import grpclib.server
-from typing import Dict
 
 
 class ThingService:

tests/inputs/bool/bool.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package bool;
+
 message Test {
     bool value = 1;
 }

tests/inputs/bool/test_bool.py

@@ -1,6 +1,19 @@
+import pytest
+
 from tests.output_betterproto.bool import Test
+from tests.output_betterproto_pydantic.bool import Test as TestPyd
 
 
 def test_value():
     message = Test()
     assert not message.value, "Boolean is False by default"
+
+
+def test_pydantic_no_value():
+    with pytest.raises(ValueError):
+        TestPyd()
+
+
+def test_pydantic_value():
+    message = Test(value=False)
+    assert not message.value

tests/inputs/bytes/bytes.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package bytes;
+
 message Test {
     bytes data = 1;
 }

tests/inputs/casing/casing.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package casing;
+
 enum my_enum {
   ZERO = 0;
   ONE = 1;

tests/inputs/casing_inner_class/casing_inner_class.proto

@@ -0,0 +1,11 @@
+// https://github.com/danielgtaylor/python-betterproto/issues/344
+syntax = "proto3";
+
+package casing_inner_class;
+
+message Test {
+  message inner_class {
+    sint32 old_exp = 1;
+  }
+  inner_class inner = 2;
+}

tests/inputs/casing_inner_class/test_casing_inner_class.py

@@ -0,0 +1,14 @@
+import tests.output_betterproto.casing_inner_class as casing_inner_class
+
+
+def test_message_casing_inner_class_name():
+    assert hasattr(
+        casing_inner_class, "TestInnerClass"
+    ), "Inline defined Message is correctly converted to CamelCase"
+
+
+def test_message_casing_inner_class_attributes():
+    message = casing_inner_class.Test()
+    assert hasattr(
+        message.inner, "old_exp"
+    ), "Inline defined Message attribute is snake_case"

tests/inputs/casing_message_field_uppercase/casing_message_field_uppercase.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package casing_message_field_uppercase;
+
 message Test {
   int32 UPPERCASE = 1;
   int32 UPPERCASE_V2 = 2;

tests/inputs/config.py

@@ -1,9 +1,7 @@
 # Test cases that are expected to fail, e.g. unimplemented features or bug-fixes.
 # Remove from list when fixed.
 xfail = {
-    "oneof_enum",  # 63
     "namespace_keywords",  # 70
-    "namespace_builtin_types",  # 53
     "googletypes_struct",  # 9
     "googletypes_value",  # 9
     "import_capitalized_package",
@@ -11,10 +9,22 @@ xfail = {
 }
 
 services = {
+    "googletypes_request",
     "googletypes_response",
     "googletypes_response_embedded",
     "service",
+    "service_separate_packages",
     "import_service_input_message",
     "googletypes_service_returns_empty",
     "googletypes_service_returns_googletype",
+    "example_service",
+    "empty_service",
+    "service_uppercase",
 }
+
+
+# Indicate json sample messages to skip when testing that json (de)serialization
+# is symmetrical becuase some cases legitimately are not symmetrical.
+# Each key references the name of the test scenario and the values in the tuple
+# Are the names of the json files.
+non_symmetrical_json = {"empty_repeated": ("empty_repeated",)}

tests/inputs/deprecated/deprecated.json

@@ -1,4 +1,6 @@
 {
-  "v": 10,
+  "message": {
+    "value": "hello"
+  },
   "value": 10
 }

tests/inputs/deprecated/deprecated.proto

@@ -1,9 +1,14 @@
 syntax = "proto3";
 
+package deprecated;
+
 // Some documentation about the Test message.
 message Test {
-    // Some documentation about the value.
-    option deprecated = true;
-    int32 v = 1 [deprecated=true];
+    Message message = 1 [deprecated=true];
     int32 value = 2;
 }
+
+message Message {
+    option deprecated = true;
+    string value = 1;
+}

tests/inputs/deprecated_field/deprecated_field.json

@@ -1,4 +0,0 @@
-{
-  "v": 10,
-  "value": 10
-}

tests/inputs/deprecated_field/deprecated_field.proto

@@ -1,8 +0,0 @@
-syntax = "proto3";
-
-// Some documentation about the Test message.
-message Test {
-    // Some documentation about the value.
-    int32 v = 1 [deprecated=true];
-    int32 value = 2;
-}

tests/inputs/double/double.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package double;
+
 message Test {
     double count = 1;
 }

tests/inputs/empty_repeated/empty_repeated.json

@@ -0,0 +1,3 @@
+{
+  "msg": [{"values":[]}]
+}

tests/inputs/empty_repeated/empty_repeated.proto

@@ -0,0 +1,11 @@
+syntax = "proto3";
+
+package empty_repeated;
+
+message MessageA {
+  repeated float values = 1;
+}
+
+message Test {
+  repeated MessageA msg = 1;
+}

tests/inputs/empty_service/empty_service.proto

@@ -0,0 +1,7 @@
+/* Empty service without comments */
+syntax = "proto3";
+
+package empty_service;
+
+service Test {
+}

tests/inputs/entry/entry.proto

@@ -0,0 +1,20 @@
+syntax = "proto3";
+
+package entry;
+
+// This is a minimal example of a repeated message field that caused issues when
+// checking whether a message is a map.
+//
+// During the check wheter a field is a "map", the string "entry" is added to
+// the field name, checked against the type name and then further checks are
+// made against the nested type of a parent message. In this edge-case, the
+// first check would pass even though it shouldn't and that would cause an
+// error because the parent type does not have a "nested_type" attribute.
+
+message Test {
+    repeated ExportEntry export = 1;
+}
+
+message ExportEntry {
+    string name = 1;
+}

tests/inputs/enum/enum.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package enum;
+
 // Tests that enums are correctly serialized and that it correctly handles skipped and out-of-order enum values
 message Test {
   Choice choice = 1;

tests/inputs/enum/test_enum.py

@@ -1,6 +1,6 @@
 from tests.output_betterproto.enum import (
-    Test,
     Choice,
+    Test,
 )
 
 

tests/inputs/example/example.proto

@@ -1,8 +1,911 @@
-syntax = "proto3";
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-package hello;
+// Author: kenton@google.com (Kenton Varda)
+//  Based on original Protocol Buffers design by
+//  Sanjay Ghemawat, Jeff Dean, and others.
+//
+// The messages in this file describe the definitions found in .proto files.
+// A valid .proto file can be translated directly to a FileDescriptorProto
+// without any other information (e.g. without reading its imports).
 
-// Greeting represents a message you can tell a user.
-message Greeting {
-  string message = 1;
+
+syntax = "proto2";
+
+package example;
+
+// package google.protobuf;
+
+option go_package = "google.golang.org/protobuf/types/descriptorpb";
+option java_package = "com.google.protobuf";
+option java_outer_classname = "DescriptorProtos";
+option csharp_namespace = "Google.Protobuf.Reflection";
+option objc_class_prefix = "GPB";
+option cc_enable_arenas = true;
+
+// descriptor.proto must be optimized for speed because reflection-based
+// algorithms don't work during bootstrapping.
+option optimize_for = SPEED;
+
+// The protocol compiler can output a FileDescriptorSet containing the .proto
+// files it parses.
+message FileDescriptorSet {
+  repeated FileDescriptorProto file = 1;
+}
+
+// Describes a complete .proto file.
+message FileDescriptorProto {
+  optional string name = 1;     // file name, relative to root of source tree
+  optional string package = 2;  // e.g. "foo", "foo.bar", etc.
+
+  // Names of files imported by this file.
+  repeated string dependency = 3;
+  // Indexes of the public imported files in the dependency list above.
+  repeated int32 public_dependency = 10;
+  // Indexes of the weak imported files in the dependency list.
+  // For Google-internal migration only. Do not use.
+  repeated int32 weak_dependency = 11;
+
+  // All top-level definitions in this file.
+  repeated DescriptorProto message_type = 4;
+  repeated EnumDescriptorProto enum_type = 5;
+  repeated ServiceDescriptorProto service = 6;
+  repeated FieldDescriptorProto extension = 7;
+
+  optional FileOptions options = 8;
+
+  // This field contains optional information about the original source code.
+  // You may safely remove this entire field without harming runtime
+  // functionality of the descriptors -- the information is needed only by
+  // development tools.
+  optional SourceCodeInfo source_code_info = 9;
+
+  // The syntax of the proto file.
+  // The supported values are "proto2" and "proto3".
+  optional string syntax = 12;
+}
+
+// Describes a message type.
+message DescriptorProto {
+  optional string name = 1;
+
+  repeated FieldDescriptorProto field = 2;
+  repeated FieldDescriptorProto extension = 6;
+
+  repeated DescriptorProto nested_type = 3;
+  repeated EnumDescriptorProto enum_type = 4;
+
+  message ExtensionRange {
+    optional int32 start = 1;  // Inclusive.
+    optional int32 end = 2;    // Exclusive.
+
+    optional ExtensionRangeOptions options = 3;
+  }
+  repeated ExtensionRange extension_range = 5;
+
+  repeated OneofDescriptorProto oneof_decl = 8;
+
+  optional MessageOptions options = 7;
+
+  // Range of reserved tag numbers. Reserved tag numbers may not be used by
+  // fields or extension ranges in the same message. Reserved ranges may
+  // not overlap.
+  message ReservedRange {
+    optional int32 start = 1;  // Inclusive.
+    optional int32 end = 2;    // Exclusive.
+  }
+  repeated ReservedRange reserved_range = 9;
+  // Reserved field names, which may not be used by fields in the same message.
+  // A given name may only be reserved once.
+  repeated string reserved_name = 10;
+}
+
+message ExtensionRangeOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+// Describes a field within a message.
+message FieldDescriptorProto {
+  enum Type {
+    // 0 is reserved for errors.
+    // Order is weird for historical reasons.
+    TYPE_DOUBLE = 1;
+    TYPE_FLOAT = 2;
+    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT64 if
+    // negative values are likely.
+    TYPE_INT64 = 3;
+    TYPE_UINT64 = 4;
+    // Not ZigZag encoded.  Negative numbers take 10 bytes.  Use TYPE_SINT32 if
+    // negative values are likely.
+    TYPE_INT32 = 5;
+    TYPE_FIXED64 = 6;
+    TYPE_FIXED32 = 7;
+    TYPE_BOOL = 8;
+    TYPE_STRING = 9;
+    // Tag-delimited aggregate.
+    // Group type is deprecated and not supported in proto3. However, Proto3
+    // implementations should still be able to parse the group wire format and
+    // treat group fields as unknown fields.
+    TYPE_GROUP = 10;
+    TYPE_MESSAGE = 11;  // Length-delimited aggregate.
+
+    // New in version 2.
+    TYPE_BYTES = 12;
+    TYPE_UINT32 = 13;
+    TYPE_ENUM = 14;
+    TYPE_SFIXED32 = 15;
+    TYPE_SFIXED64 = 16;
+    TYPE_SINT32 = 17;  // Uses ZigZag encoding.
+    TYPE_SINT64 = 18;  // Uses ZigZag encoding.
+  }
+
+  enum Label {
+    // 0 is reserved for errors
+    LABEL_OPTIONAL = 1;
+    LABEL_REQUIRED = 2;
+    LABEL_REPEATED = 3;
+  }
+
+  optional string name = 1;
+  optional int32 number = 3;
+  optional Label label = 4;
+
+  // If type_name is set, this need not be set.  If both this and type_name
+  // are set, this must be one of TYPE_ENUM, TYPE_MESSAGE or TYPE_GROUP.
+  optional Type type = 5;
+
+  // For message and enum types, this is the name of the type.  If the name
+  // starts with a '.', it is fully-qualified.  Otherwise, C++-like scoping
+  // rules are used to find the type (i.e. first the nested types within this
+  // message are searched, then within the parent, on up to the root
+  // namespace).
+  optional string type_name = 6;
+
+  // For extensions, this is the name of the type being extended.  It is
+  // resolved in the same manner as type_name.
+  optional string extendee = 2;
+
+  // For numeric types, contains the original text representation of the value.
+  // For booleans, "true" or "false".
+  // For strings, contains the default text contents (not escaped in any way).
+  // For bytes, contains the C escaped value.  All bytes >= 128 are escaped.
+  // TODO(kenton):  Base-64 encode?
+  optional string default_value = 7;
+
+  // If set, gives the index of a oneof in the containing type's oneof_decl
+  // list.  This field is a member of that oneof.
+  optional int32 oneof_index = 9;
+
+  // JSON name of this field. The value is set by protocol compiler. If the
+  // user has set a "json_name" option on this field, that option's value
+  // will be used. Otherwise, it's deduced from the field's name by converting
+  // it to camelCase.
+  optional string json_name = 10;
+
+  optional FieldOptions options = 8;
+
+  // If true, this is a proto3 "optional". When a proto3 field is optional, it
+  // tracks presence regardless of field type.
+  //
+  // When proto3_optional is true, this field must be belong to a oneof to
+  // signal to old proto3 clients that presence is tracked for this field. This
+  // oneof is known as a "synthetic" oneof, and this field must be its sole
+  // member (each proto3 optional field gets its own synthetic oneof). Synthetic
+  // oneofs exist in the descriptor only, and do not generate any API. Synthetic
+  // oneofs must be ordered after all "real" oneofs.
+  //
+  // For message fields, proto3_optional doesn't create any semantic change,
+  // since non-repeated message fields always track presence. However it still
+  // indicates the semantic detail of whether the user wrote "optional" or not.
+  // This can be useful for round-tripping the .proto file. For consistency we
+  // give message fields a synthetic oneof also, even though it is not required
+  // to track presence. This is especially important because the parser can't
+  // tell if a field is a message or an enum, so it must always create a
+  // synthetic oneof.
+  //
+  // Proto2 optional fields do not set this flag, because they already indicate
+  // optional with `LABEL_OPTIONAL`.
+  optional bool proto3_optional = 17;
+}
+
+// Describes a oneof.
+message OneofDescriptorProto {
+  optional string name = 1;
+  optional OneofOptions options = 2;
+}
+
+// Describes an enum type.
+message EnumDescriptorProto {
+  optional string name = 1;
+
+  repeated EnumValueDescriptorProto value = 2;
+
+  optional EnumOptions options = 3;
+
+  // Range of reserved numeric values. Reserved values may not be used by
+  // entries in the same enum. Reserved ranges may not overlap.
+  //
+  // Note that this is distinct from DescriptorProto.ReservedRange in that it
+  // is inclusive such that it can appropriately represent the entire int32
+  // domain.
+  message EnumReservedRange {
+    optional int32 start = 1;  // Inclusive.
+    optional int32 end = 2;    // Inclusive.
+  }
+
+  // Range of reserved numeric values. Reserved numeric values may not be used
+  // by enum values in the same enum declaration. Reserved ranges may not
+  // overlap.
+  repeated EnumReservedRange reserved_range = 4;
+
+  // Reserved enum value names, which may not be reused. A given name may only
+  // be reserved once.
+  repeated string reserved_name = 5;
+}
+
+// Describes a value within an enum.
+message EnumValueDescriptorProto {
+  optional string name = 1;
+  optional int32 number = 2;
+
+  optional EnumValueOptions options = 3;
+}
+
+// Describes a service.
+message ServiceDescriptorProto {
+  optional string name = 1;
+  repeated MethodDescriptorProto method = 2;
+
+  optional ServiceOptions options = 3;
+}
+
+// Describes a method of a service.
+message MethodDescriptorProto {
+  optional string name = 1;
+
+  // Input and output type names.  These are resolved in the same way as
+  // FieldDescriptorProto.type_name, but must refer to a message type.
+  optional string input_type = 2;
+  optional string output_type = 3;
+
+  optional MethodOptions options = 4;
+
+  // Identifies if client streams multiple client messages
+  optional bool client_streaming = 5 [default = false];
+  // Identifies if server streams multiple server messages
+  optional bool server_streaming = 6 [default = false];
+}
+
+
+// ===================================================================
+// Options
+
+// Each of the definitions above may have "options" attached.  These are
+// just annotations which may cause code to be generated slightly differently
+// or may contain hints for code that manipulates protocol messages.
+//
+// Clients may define custom options as extensions of the *Options messages.
+// These extensions may not yet be known at parsing time, so the parser cannot
+// store the values in them.  Instead it stores them in a field in the *Options
+// message called uninterpreted_option. This field must have the same name
+// across all *Options messages. We then use this field to populate the
+// extensions when we build a descriptor, at which point all protos have been
+// parsed and so all extensions are known.
+//
+// Extension numbers for custom options may be chosen as follows:
+// * For options which will only be used within a single application or
+//   organization, or for experimental options, use field numbers 50000
+//   through 99999.  It is up to you to ensure that you do not use the
+//   same number for multiple options.
+// * For options which will be published and used publicly by multiple
+//   independent entities, e-mail protobuf-global-extension-registry@google.com
+//   to reserve extension numbers. Simply provide your project name (e.g.
+//   Objective-C plugin) and your project website (if available) -- there's no
+//   need to explain how you intend to use them. Usually you only need one
+//   extension number. You can declare multiple options with only one extension
+//   number by putting them in a sub-message. See the Custom Options section of
+//   the docs for examples:
+//   https://developers.google.com/protocol-buffers/docs/proto#options
+//   If this turns out to be popular, a web service will be set up
+//   to automatically assign option numbers.
+
+message FileOptions {
+
+  // Sets the Java package where classes generated from this .proto will be
+  // placed.  By default, the proto package is used, but this is often
+  // inappropriate because proto packages do not normally start with backwards
+  // domain names.
+  optional string java_package = 1;
+
+
+  // If set, all the classes from the .proto file are wrapped in a single
+  // outer class with the given name.  This applies to both Proto1
+  // (equivalent to the old "--one_java_file" option) and Proto2 (where
+  // a .proto always translates to a single class, but you may want to
+  // explicitly choose the class name).
+  optional string java_outer_classname = 8;
+
+  // If set true, then the Java code generator will generate a separate .java
+  // file for each top-level message, enum, and service defined in the .proto
+  // file.  Thus, these types will *not* be nested inside the outer class
+  // named by java_outer_classname.  However, the outer class will still be
+  // generated to contain the file's getDescriptor() method as well as any
+  // top-level extensions defined in the file.
+  optional bool java_multiple_files = 10 [default = false];
+
+  // This option does nothing.
+  optional bool java_generate_equals_and_hash = 20 [deprecated=true];
+
+  // If set true, then the Java2 code generator will generate code that
+  // throws an exception whenever an attempt is made to assign a non-UTF-8
+  // byte sequence to a string field.
+  // Message reflection will do the same.
+  // However, an extension field still accepts non-UTF-8 byte sequences.
+  // This option has no effect on when used with the lite runtime.
+  optional bool java_string_check_utf8 = 27 [default = false];
+
+
+  // Generated classes can be optimized for speed or code size.
+  enum OptimizeMode {
+    SPEED = 1;         // Generate complete code for parsing, serialization,
+                       // etc.
+    CODE_SIZE = 2;     // Use ReflectionOps to implement these methods.
+    LITE_RUNTIME = 3;  // Generate code using MessageLite and the lite runtime.
+  }
+  optional OptimizeMode optimize_for = 9 [default = SPEED];
+
+  // Sets the Go package where structs generated from this .proto will be
+  // placed. If omitted, the Go package will be derived from the following:
+  //   - The basename of the package import path, if provided.
+  //   - Otherwise, the package statement in the .proto file, if present.
+  //   - Otherwise, the basename of the .proto file, without extension.
+  optional string go_package = 11;
+
+
+
+
+  // Should generic services be generated in each language?  "Generic" services
+  // are not specific to any particular RPC system.  They are generated by the
+  // main code generators in each language (without additional plugins).
+  // Generic services were the only kind of service generation supported by
+  // early versions of google.protobuf.
+  //
+  // Generic services are now considered deprecated in favor of using plugins
+  // that generate code specific to your particular RPC system.  Therefore,
+  // these default to false.  Old code which depends on generic services should
+  // explicitly set them to true.
+  optional bool cc_generic_services = 16 [default = false];
+  optional bool java_generic_services = 17 [default = false];
+  optional bool py_generic_services = 18 [default = false];
+  optional bool php_generic_services = 42 [default = false];
+
+  // Is this file deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for everything in the file, or it will be completely ignored; in the very
+  // least, this is a formalization for deprecating files.
+  optional bool deprecated = 23 [default = false];
+
+  // Enables the use of arenas for the proto messages in this file. This applies
+  // only to generated classes for C++.
+  optional bool cc_enable_arenas = 31 [default = true];
+
+
+  // Sets the objective c class prefix which is prepended to all objective c
+  // generated classes from this .proto. There is no default.
+  optional string objc_class_prefix = 36;
+
+  // Namespace for generated classes; defaults to the package.
+  optional string csharp_namespace = 37;
+
+  // By default Swift generators will take the proto package and CamelCase it
+  // replacing '.' with underscore and use that to prefix the types/symbols
+  // defined. When this options is provided, they will use this value instead
+  // to prefix the types/symbols defined.
+  optional string swift_prefix = 39;
+
+  // Sets the php class prefix which is prepended to all php generated classes
+  // from this .proto. Default is empty.
+  optional string php_class_prefix = 40;
+
+  // Use this option to change the namespace of php generated classes. Default
+  // is empty. When this option is empty, the package name will be used for
+  // determining the namespace.
+  optional string php_namespace = 41;
+
+  // Use this option to change the namespace of php generated metadata classes.
+  // Default is empty. When this option is empty, the proto file name will be
+  // used for determining the namespace.
+  optional string php_metadata_namespace = 44;
+
+  // Use this option to change the package of ruby generated classes. Default
+  // is empty. When this option is not set, the package name will be used for
+  // determining the ruby package.
+  optional string ruby_package = 45;
+
+
+  // The parser stores options it doesn't recognize here.
+  // See the documentation for the "Options" section above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message.
+  // See the documentation for the "Options" section above.
+  extensions 1000 to max;
+
+  reserved 38;
+}
+
+message MessageOptions {
+  // Set true to use the old proto1 MessageSet wire format for extensions.
+  // This is provided for backwards-compatibility with the MessageSet wire
+  // format.  You should not use this for any other reason:  It's less
+  // efficient, has fewer features, and is more complicated.
+  //
+  // The message must be defined exactly as follows:
+  //   message Foo {
+  //     option message_set_wire_format = true;
+  //     extensions 4 to max;
+  //   }
+  // Note that the message cannot have any defined fields; MessageSets only
+  // have extensions.
+  //
+  // All extensions of your type must be singular messages; e.g. they cannot
+  // be int32s, enums, or repeated messages.
+  //
+  // Because this is an option, the above two restrictions are not enforced by
+  // the protocol compiler.
+  optional bool message_set_wire_format = 1 [default = false];
+
+  // Disables the generation of the standard "descriptor()" accessor, which can
+  // conflict with a field of the same name.  This is meant to make migration
+  // from proto1 easier; new code should avoid fields named "descriptor".
+  optional bool no_standard_descriptor_accessor = 2 [default = false];
+
+  // Is this message deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the message, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating messages.
+  optional bool deprecated = 3 [default = false];
+
+  // Whether the message is an automatically generated map entry type for the
+  // maps field.
+  //
+  // For maps fields:
+  //     map<KeyType, ValueType> map_field = 1;
+  // The parsed descriptor looks like:
+  //     message MapFieldEntry {
+  //         option map_entry = true;
+  //         optional KeyType key = 1;
+  //         optional ValueType value = 2;
+  //     }
+  //     repeated MapFieldEntry map_field = 1;
+  //
+  // Implementations may choose not to generate the map_entry=true message, but
+  // use a native map in the target language to hold the keys and values.
+  // The reflection APIs in such implementations still need to work as
+  // if the field is a repeated message field.
+  //
+  // NOTE: Do not set the option in .proto files. Always use the maps syntax
+  // instead. The option should only be implicitly set by the proto compiler
+  // parser.
+  optional bool map_entry = 7;
+
+  reserved 8;  // javalite_serializable
+  reserved 9;  // javanano_as_lite
+
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message FieldOptions {
+  // The ctype option instructs the C++ code generator to use a different
+  // representation of the field than it normally would.  See the specific
+  // options below.  This option is not yet implemented in the open source
+  // release -- sorry, we'll try to include it in a future version!
+  optional CType ctype = 1 [default = STRING];
+  enum CType {
+    // Default mode.
+    STRING = 0;
+
+    CORD = 1;
+
+    STRING_PIECE = 2;
+  }
+  // The packed option can be enabled for repeated primitive fields to enable
+  // a more efficient representation on the wire. Rather than repeatedly
+  // writing the tag and type for each element, the entire array is encoded as
+  // a single length-delimited blob. In proto3, only explicit setting it to
+  // false will avoid using packed encoding.
+  optional bool packed = 2;
+
+  // The jstype option determines the JavaScript type used for values of the
+  // field.  The option is permitted only for 64 bit integral and fixed types
+  // (int64, uint64, sint64, fixed64, sfixed64).  A field with jstype JS_STRING
+  // is represented as JavaScript string, which avoids loss of precision that
+  // can happen when a large value is converted to a floating point JavaScript.
+  // Specifying JS_NUMBER for the jstype causes the generated JavaScript code to
+  // use the JavaScript "number" type.  The behavior of the default option
+  // JS_NORMAL is implementation dependent.
+  //
+  // This option is an enum to permit additional types to be added, e.g.
+  // goog.math.Integer.
+  optional JSType jstype = 6 [default = JS_NORMAL];
+  enum JSType {
+    // Use the default type.
+    JS_NORMAL = 0;
+
+    // Use JavaScript strings.
+    JS_STRING = 1;
+
+    // Use JavaScript numbers.
+    JS_NUMBER = 2;
+  }
+
+  // Should this field be parsed lazily?  Lazy applies only to message-type
+  // fields.  It means that when the outer message is initially parsed, the
+  // inner message's contents will not be parsed but instead stored in encoded
+  // form.  The inner message will actually be parsed when it is first accessed.
+  //
+  // This is only a hint.  Implementations are free to choose whether to use
+  // eager or lazy parsing regardless of the value of this option.  However,
+  // setting this option true suggests that the protocol author believes that
+  // using lazy parsing on this field is worth the additional bookkeeping
+  // overhead typically needed to implement it.
+  //
+  // This option does not affect the public interface of any generated code;
+  // all method signatures remain the same.  Furthermore, thread-safety of the
+  // interface is not affected by this option; const methods remain safe to
+  // call from multiple threads concurrently, while non-const methods continue
+  // to require exclusive access.
+  //
+  //
+  // Note that implementations may choose not to check required fields within
+  // a lazy sub-message.  That is, calling IsInitialized() on the outer message
+  // may return true even if the inner message has missing required fields.
+  // This is necessary because otherwise the inner message would have to be
+  // parsed in order to perform the check, defeating the purpose of lazy
+  // parsing.  An implementation which chooses not to check required fields
+  // must be consistent about it.  That is, for any particular sub-message, the
+  // implementation must either *always* check its required fields, or *never*
+  // check its required fields, regardless of whether or not the message has
+  // been parsed.
+  optional bool lazy = 5 [default = false];
+
+  // Is this field deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for accessors, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating fields.
+  optional bool deprecated = 3 [default = false];
+
+  // For Google-internal migration only. Do not use.
+  optional bool weak = 10 [default = false];
+
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+
+  reserved 4;  // removed jtype
+}
+
+message OneofOptions {
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumOptions {
+
+  // Set this option to true to allow mapping different tag names to the same
+  // value.
+  optional bool allow_alias = 2;
+
+  // Is this enum deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the enum, or it will be completely ignored; in the very least, this
+  // is a formalization for deprecating enums.
+  optional bool deprecated = 3 [default = false];
+
+  reserved 5;  // javanano_as_lite
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message EnumValueOptions {
+  // Is this enum value deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the enum value, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating enum values.
+  optional bool deprecated = 1 [default = false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message ServiceOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // Is this service deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the service, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating services.
+  optional bool deprecated = 33 [default = false];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+message MethodOptions {
+
+  // Note:  Field numbers 1 through 32 are reserved for Google's internal RPC
+  //   framework.  We apologize for hoarding these numbers to ourselves, but
+  //   we were already using them long before we decided to release Protocol
+  //   Buffers.
+
+  // Is this method deprecated?
+  // Depending on the target platform, this can emit Deprecated annotations
+  // for the method, or it will be completely ignored; in the very least,
+  // this is a formalization for deprecating methods.
+  optional bool deprecated = 33 [default = false];
+
+  // Is this method side-effect-free (or safe in HTTP parlance), or idempotent,
+  // or neither? HTTP based RPC implementation may choose GET verb for safe
+  // methods, and PUT verb for idempotent methods instead of the default POST.
+  enum IdempotencyLevel {
+    IDEMPOTENCY_UNKNOWN = 0;
+    NO_SIDE_EFFECTS = 1;  // implies idempotent
+    IDEMPOTENT = 2;       // idempotent, but may have side effects
+  }
+  optional IdempotencyLevel idempotency_level = 34
+      [default = IDEMPOTENCY_UNKNOWN];
+
+  // The parser stores options it doesn't recognize here. See above.
+  repeated UninterpretedOption uninterpreted_option = 999;
+
+  // Clients can define custom options in extensions of this message. See above.
+  extensions 1000 to max;
+}
+
+
+// A message representing a option the parser does not recognize. This only
+// appears in options protos created by the compiler::Parser class.
+// DescriptorPool resolves these when building Descriptor objects. Therefore,
+// options protos in descriptor objects (e.g. returned by Descriptor::options(),
+// or produced by Descriptor::CopyTo()) will never have UninterpretedOptions
+// in them.
+message UninterpretedOption {
+  // The name of the uninterpreted option.  Each string represents a segment in
+  // a dot-separated name.  is_extension is true iff a segment represents an
+  // extension (denoted with parentheses in options specs in .proto files).
+  // E.g.,{ ["foo", false], ["bar.baz", true], ["qux", false] } represents
+  // "foo.(bar.baz).qux".
+  message NamePart {
+    required string name_part = 1;
+    required bool is_extension = 2;
+  }
+  repeated NamePart name = 2;
+
+  // The value of the uninterpreted option, in whatever type the tokenizer
+  // identified it as during parsing. Exactly one of these should be set.
+  optional string identifier_value = 3;
+  optional uint64 positive_int_value = 4;
+  optional int64 negative_int_value = 5;
+  optional double double_value = 6;
+  optional bytes string_value = 7;
+  optional string aggregate_value = 8;
+}
+
+// ===================================================================
+// Optional source code info
+
+// Encapsulates information about the original source file from which a
+// FileDescriptorProto was generated.
+message SourceCodeInfo {
+  // A Location identifies a piece of source code in a .proto file which
+  // corresponds to a particular definition.  This information is intended
+  // to be useful to IDEs, code indexers, documentation generators, and similar
+  // tools.
+  //
+  // For example, say we have a file like:
+  //   message Foo {
+  //     optional string foo = 1;
+  //   }
+  // Let's look at just the field definition:
+  //   optional string foo = 1;
+  //   ^       ^^     ^^  ^  ^^^
+  //   a       bc     de  f  ghi
+  // We have the following locations:
+  //   span   path               represents
+  //   [a,i)  [ 4, 0, 2, 0 ]     The whole field definition.
+  //   [a,b)  [ 4, 0, 2, 0, 4 ]  The label (optional).
+  //   [c,d)  [ 4, 0, 2, 0, 5 ]  The type (string).
+  //   [e,f)  [ 4, 0, 2, 0, 1 ]  The name (foo).
+  //   [g,h)  [ 4, 0, 2, 0, 3 ]  The number (1).
+  //
+  // Notes:
+  // - A location may refer to a repeated field itself (i.e. not to any
+  //   particular index within it).  This is used whenever a set of elements are
+  //   logically enclosed in a single code segment.  For example, an entire
+  //   extend block (possibly containing multiple extension definitions) will
+  //   have an outer location whose path refers to the "extensions" repeated
+  //   field without an index.
+  // - Multiple locations may have the same path.  This happens when a single
+  //   logical declaration is spread out across multiple places.  The most
+  //   obvious example is the "extend" block again -- there may be multiple
+  //   extend blocks in the same scope, each of which will have the same path.
+  // - A location's span is not always a subset of its parent's span.  For
+  //   example, the "extendee" of an extension declaration appears at the
+  //   beginning of the "extend" block and is shared by all extensions within
+  //   the block.
+  // - Just because a location's span is a subset of some other location's span
+  //   does not mean that it is a descendant.  For example, a "group" defines
+  //   both a type and a field in a single declaration.  Thus, the locations
+  //   corresponding to the type and field and their components will overlap.
+  // - Code which tries to interpret locations should probably be designed to
+  //   ignore those that it doesn't understand, as more types of locations could
+  //   be recorded in the future.
+  repeated Location location = 1;
+  message Location {
+    // Identifies which part of the FileDescriptorProto was defined at this
+    // location.
+    //
+    // Each element is a field number or an index.  They form a path from
+    // the root FileDescriptorProto to the place where the definition.  For
+    // example, this path:
+    //   [ 4, 3, 2, 7, 1 ]
+    // refers to:
+    //   file.message_type(3)  // 4, 3
+    //       .field(7)         // 2, 7
+    //       .name()           // 1
+    // This is because FileDescriptorProto.message_type has field number 4:
+    //   repeated DescriptorProto message_type = 4;
+    // and DescriptorProto.field has field number 2:
+    //   repeated FieldDescriptorProto field = 2;
+    // and FieldDescriptorProto.name has field number 1:
+    //   optional string name = 1;
+    //
+    // Thus, the above path gives the location of a field name.  If we removed
+    // the last element:
+    //   [ 4, 3, 2, 7 ]
+    // this path refers to the whole field declaration (from the beginning
+    // of the label to the terminating semicolon).
+    repeated int32 path = 1 [packed = true];
+
+    // Always has exactly three or four elements: start line, start column,
+    // end line (optional, otherwise assumed same as start line), end column.
+    // These are packed into a single field for efficiency.  Note that line
+    // and column numbers are zero-based -- typically you will want to add
+    // 1 to each before displaying to a user.
+    repeated int32 span = 2 [packed = true];
+
+    // If this SourceCodeInfo represents a complete declaration, these are any
+    // comments appearing before and after the declaration which appear to be
+    // attached to the declaration.
+    //
+    // A series of line comments appearing on consecutive lines, with no other
+    // tokens appearing on those lines, will be treated as a single comment.
+    //
+    // leading_detached_comments will keep paragraphs of comments that appear
+    // before (but not connected to) the current element. Each paragraph,
+    // separated by empty lines, will be one comment element in the repeated
+    // field.
+    //
+    // Only the comment content is provided; comment markers (e.g. //) are
+    // stripped out.  For block comments, leading whitespace and an asterisk
+    // will be stripped from the beginning of each line other than the first.
+    // Newlines are included in the output.
+    //
+    // Examples:
+    //
+    //   optional int32 foo = 1;  // Comment attached to foo.
+    //   // Comment attached to bar.
+    //   optional int32 bar = 2;
+    //
+    //   optional string baz = 3;
+    //   // Comment attached to baz.
+    //   // Another line attached to baz.
+    //
+    //   // Comment attached to qux.
+    //   //
+    //   // Another line attached to qux.
+    //   optional double qux = 4;
+    //
+    //   // Detached comment for corge. This is not leading or trailing comments
+    //   // to qux or corge because there are blank lines separating it from
+    //   // both.
+    //
+    //   // Detached comment for corge paragraph 2.
+    //
+    //   optional string corge = 5;
+    //   /* Block comment attached
+    //    * to corge.  Leading asterisks
+    //    * will be removed. */
+    //   /* Block comment attached to
+    //    * grault. */
+    //   optional int32 grault = 6;
+    //
+    //   // ignored detached comments.
+    optional string leading_comments = 3;
+    optional string trailing_comments = 4;
+    repeated string leading_detached_comments = 6;
+  }
+}
+
+// Describes the relationship between generated code and its original source
+// file. A GeneratedCodeInfo message is associated with only one generated
+// source file, but may contain references to different source .proto files.
+message GeneratedCodeInfo {
+  // An Annotation connects some span of text in generated code to an element
+  // of its generating .proto file.
+  repeated Annotation annotation = 1;
+  message Annotation {
+    // Identifies the element in the original source .proto file. This field
+    // is formatted the same as SourceCodeInfo.Location.path.
+    repeated int32 path = 1 [packed = true];
+
+    // Identifies the filesystem path to the original source .proto.
+    optional string source_file = 2;
+
+    // Identifies the starting offset in bytes in the generated code
+    // that relates to the identified object.
+    optional int32 begin = 3;
+
+    // Identifies the ending offset in bytes in the generated code that
+    // relates to the identified offset. The end offset should be one past
+    // the last relevant byte (so the length of the text = end - begin).
+    optional int32 end = 4;
+  }
 }

tests/inputs/example_service/example_service.proto

@@ -0,0 +1,20 @@
+syntax = "proto3";
+
+package example_service;
+
+service Test {
+  rpc ExampleUnaryUnary(ExampleRequest) returns (ExampleResponse);
+  rpc ExampleUnaryStream(ExampleRequest) returns (stream ExampleResponse);
+  rpc ExampleStreamUnary(stream ExampleRequest) returns (ExampleResponse);
+  rpc ExampleStreamStream(stream ExampleRequest) returns (stream ExampleResponse);
+}
+
+message ExampleRequest {
+  string example_string = 1;
+  int64  example_integer = 2;
+}
+
+message ExampleResponse {
+  string example_string = 1;
+  int64  example_integer = 2;
+}

tests/inputs/example_service/test_example_service.py

@@ -0,0 +1,86 @@
+from typing import (
+    AsyncIterable,
+    AsyncIterator,
+)
+
+import pytest
+from grpclib.testing import ChannelFor
+
+from tests.output_betterproto.example_service import (
+    ExampleRequest,
+    ExampleResponse,
+    TestBase,
+    TestStub,
+)
+
+
+class ExampleService(TestBase):
+    async def example_unary_unary(
+        self, example_request: ExampleRequest
+    ) -> "ExampleResponse":
+        return ExampleResponse(
+            example_string=example_request.example_string,
+            example_integer=example_request.example_integer,
+        )
+
+    async def example_unary_stream(
+        self, example_request: ExampleRequest
+    ) -> AsyncIterator["ExampleResponse"]:
+        response = ExampleResponse(
+            example_string=example_request.example_string,
+            example_integer=example_request.example_integer,
+        )
+        yield response
+        yield response
+        yield response
+
+    async def example_stream_unary(
+        self, example_request_iterator: AsyncIterator["ExampleRequest"]
+    ) -> "ExampleResponse":
+        async for example_request in example_request_iterator:
+            return ExampleResponse(
+                example_string=example_request.example_string,
+                example_integer=example_request.example_integer,
+            )
+
+    async def example_stream_stream(
+        self, example_request_iterator: AsyncIterator["ExampleRequest"]
+    ) -> AsyncIterator["ExampleResponse"]:
+        async for example_request in example_request_iterator:
+            yield ExampleResponse(
+                example_string=example_request.example_string,
+                example_integer=example_request.example_integer,
+            )
+
+
+@pytest.mark.asyncio
+async def test_calls_with_different_cardinalities():
+    example_request = ExampleRequest("test string", 42)
+
+    async with ChannelFor([ExampleService()]) as channel:
+        stub = TestStub(channel)
+
+        # unary unary
+        response = await stub.example_unary_unary(example_request)
+        assert response.example_string == example_request.example_string
+        assert response.example_integer == example_request.example_integer
+
+        # unary stream
+        async for response in stub.example_unary_stream(example_request):
+            assert response.example_string == example_request.example_string
+            assert response.example_integer == example_request.example_integer
+
+        # stream unary
+        async def request_iterator():
+            yield example_request
+            yield example_request
+            yield example_request
+
+        response = await stub.example_stream_unary(request_iterator())
+        assert response.example_string == example_request.example_string
+        assert response.example_integer == example_request.example_integer
+
+        # stream stream
+        async for response in stub.example_stream_stream(request_iterator()):
+            assert response.example_string == example_request.example_string
+            assert response.example_integer == example_request.example_integer

tests/inputs/field_name_identical_to_type/field_name_identical_to_type.json

@@ -0,0 +1,7 @@
+{
+    "int": 26,
+    "float": 26.0,
+    "str": "value-for-str",
+    "bytes": "001a",
+    "bool": true
+}

tests/inputs/field_name_identical_to_type/field_name_identical_to_type.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+package field_name_identical_to_type;
+
+// Tests that messages may contain fields with names that are identical to their python types (PR #294)
+
+message Test {
+    int32 int = 1;
+    float float = 2;
+    string str = 3;
+    bytes bytes = 4;
+    bool bool = 5;
+}

tests/inputs/fixed/fixed.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package fixed;
+
 message Test {
   fixed32 foo = 1;
   sfixed32 bar = 2;

tests/inputs/float/float.json

@@ -0,0 +1,9 @@
+{
+    "positive": "Infinity",
+    "negative": "-Infinity",
+    "nan": "NaN",
+    "three": 3.0,
+    "threePointOneFour": 3.14,
+    "negThree": -3.0,
+    "negThreePointOneFour": -3.14
+  }

tests/inputs/float/float.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+
+package float;
+
+// Some documentation about the Test message.
+message Test {
+    double positive = 1;
+    double negative = 2;
+    double nan = 3;
+    double three = 4;
+    double three_point_one_four = 5;
+    double neg_three = 6;
+    double neg_three_point_one_four = 7;
+}

tests/inputs/google_impl_behavior_equivalence/google_impl_behavior_equivalence.proto

@@ -1,13 +1,17 @@
 syntax = "proto3";
 
-message Foo{
-  int64 bar = 1;
-}
+package google_impl_behavior_equivalence;
 
-message Test{
-  oneof group{
+message Foo { int64 bar = 1; }
+
+message Test {
+  oneof group {
     string string = 1;
     int64 integer = 2;
     Foo foo = 3;
   }
 }
+
+message Request { Empty foo = 1; }
+
+message Empty {}

tests/inputs/google_impl_behavior_equivalence/test_google_impl_behavior_equivalence.py

@@ -1,19 +1,22 @@
 import pytest
-
 from google.protobuf import json_format
+
 import betterproto
 from tests.output_betterproto.google_impl_behavior_equivalence import (
-    Test,
+    Empty,
     Foo,
+    Request,
+    Test,
 )
 from tests.output_reference.google_impl_behavior_equivalence.google_impl_behavior_equivalence_pb2 import (
-    Test as ReferenceTest,
+    Empty as ReferenceEmpty,
     Foo as ReferenceFoo,
+    Request as ReferenceRequest,
+    Test as ReferenceTest,
 )
 
 
 def test_oneof_serializes_similar_to_google_oneof():
-
     tests = [
         (Test(string="abc"), ReferenceTest(string="abc")),
         (Test(integer=2), ReferenceTest(integer=2)),
@@ -30,7 +33,6 @@ def test_oneof_serializes_similar_to_google_oneof():
 
 
 def test_bytes_are_the_same_for_oneof():
-
     message = Test(string="")
     message_reference = ReferenceTest(string="")
 
@@ -48,8 +50,23 @@ def test_bytes_are_the_same_for_oneof():
 
     # None of these fields were explicitly set BUT they should not actually be null
     # themselves
-    assert isinstance(message.foo, Foo)
-    assert isinstance(message2.foo, Foo)
+    assert not hasattr(message, "foo")
+    assert object.__getattribute__(message, "foo") == betterproto.PLACEHOLDER
+    assert not hasattr(message2, "foo")
+    assert object.__getattribute__(message2, "foo") == betterproto.PLACEHOLDER
 
     assert isinstance(message_reference.foo, ReferenceFoo)
     assert isinstance(message_reference2.foo, ReferenceFoo)
+
+
+def test_empty_message_field():
+    message = Request()
+    reference_message = ReferenceRequest()
+
+    message.foo = Empty()
+    reference_message.foo.CopyFrom(ReferenceEmpty())
+
+    assert betterproto.serialized_on_wire(message.foo)
+    assert reference_message.HasField("foo")
+
+    assert bytes(message) == reference_message.SerializeToString()

tests/inputs/googletypes/googletypes.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes;
+
 import "google/protobuf/duration.proto";
 import "google/protobuf/timestamp.proto";
 import "google/protobuf/wrappers.proto";

tests/inputs/googletypes_request/googletypes_request.proto

@@ -0,0 +1,29 @@
+syntax = "proto3";
+
+package googletypes_request;
+
+import "google/protobuf/duration.proto";
+import "google/protobuf/empty.proto";
+import "google/protobuf/timestamp.proto";
+import "google/protobuf/wrappers.proto";
+
+// Tests that google types can be used as params
+
+service Test {
+    rpc SendDouble (google.protobuf.DoubleValue) returns (Input);
+    rpc SendFloat (google.protobuf.FloatValue) returns (Input);
+    rpc SendInt64 (google.protobuf.Int64Value) returns (Input);
+    rpc SendUInt64 (google.protobuf.UInt64Value) returns (Input);
+    rpc SendInt32 (google.protobuf.Int32Value) returns (Input);
+    rpc SendUInt32 (google.protobuf.UInt32Value) returns (Input);
+    rpc SendBool (google.protobuf.BoolValue) returns (Input);
+    rpc SendString (google.protobuf.StringValue) returns (Input);
+    rpc SendBytes (google.protobuf.BytesValue) returns (Input);
+    rpc SendDatetime (google.protobuf.Timestamp) returns (Input);
+    rpc SendTimedelta (google.protobuf.Duration) returns (Input);
+    rpc SendEmpty (google.protobuf.Empty) returns (Input);
+}
+
+message Input {
+
+}

tests/inputs/googletypes_request/test_googletypes_request.py

@@ -0,0 +1,47 @@
+from datetime import (
+    datetime,
+    timedelta,
+)
+from typing import (
+    Any,
+    Callable,
+)
+
+import pytest
+
+import betterproto.lib.google.protobuf as protobuf
+from tests.mocks import MockChannel
+from tests.output_betterproto.googletypes_request import (
+    Input,
+    TestStub,
+)
+
+
+test_cases = [
+    (TestStub.send_double, protobuf.DoubleValue, 2.5),
+    (TestStub.send_float, protobuf.FloatValue, 2.5),
+    (TestStub.send_int64, protobuf.Int64Value, -64),
+    (TestStub.send_u_int64, protobuf.UInt64Value, 64),
+    (TestStub.send_int32, protobuf.Int32Value, -32),
+    (TestStub.send_u_int32, protobuf.UInt32Value, 32),
+    (TestStub.send_bool, protobuf.BoolValue, True),
+    (TestStub.send_string, protobuf.StringValue, "string"),
+    (TestStub.send_bytes, protobuf.BytesValue, bytes(0xFF)[0:4]),
+    (TestStub.send_datetime, protobuf.Timestamp, datetime(2038, 1, 19, 3, 14, 8)),
+    (TestStub.send_timedelta, protobuf.Duration, timedelta(seconds=123456)),
+]
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(["service_method", "wrapper_class", "value"], test_cases)
+async def test_channel_receives_wrapped_type(
+    service_method: Callable[[TestStub, Input], Any], wrapper_class: Callable, value
+):
+    wrapped_value = wrapper_class()
+    wrapped_value.value = value
+    channel = MockChannel(responses=[Input()])
+    service = TestStub(channel)
+
+    await service_method(service, wrapped_value)
+
+    assert channel.requests[0]["request"] == type(wrapped_value)

tests/inputs/googletypes_response/googletypes_response.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes_response;
+
 import "google/protobuf/wrappers.proto";
 
 // Tests that wrapped values can be used directly as return values

tests/inputs/googletypes_response/test_googletypes_response.py

@@ -1,10 +1,18 @@
-from typing import Any, Callable, Optional
+from typing import (
+    Any,
+    Callable,
+    Optional,
+)
 
-import betterproto.lib.google.protobuf as protobuf
 import pytest
 
+import betterproto.lib.google.protobuf as protobuf
 from tests.mocks import MockChannel
-from tests.output_betterproto.googletypes_response import TestStub
+from tests.output_betterproto.googletypes_response import (
+    Input,
+    TestStub,
+)
+
 
 test_cases = [
     (TestStub.get_double, protobuf.DoubleValue, 2.5),
@@ -22,14 +30,15 @@ test_cases = [
 @pytest.mark.asyncio
 @pytest.mark.parametrize(["service_method", "wrapper_class", "value"], test_cases)
 async def test_channel_receives_wrapped_type(
-    service_method: Callable[[TestStub], Any], wrapper_class: Callable, value
+    service_method: Callable[[TestStub, Input], Any], wrapper_class: Callable, value
 ):
     wrapped_value = wrapper_class()
     wrapped_value.value = value
     channel = MockChannel(responses=[wrapped_value])
     service = TestStub(channel)
+    method_param = Input()
 
-    await service_method(service)
+    await service_method(service, method_param)
 
     assert channel.requests[0]["response_type"] != Optional[type(value)]
     assert channel.requests[0]["response_type"] == type(wrapped_value)
@@ -39,7 +48,7 @@ async def test_channel_receives_wrapped_type(
 @pytest.mark.xfail
 @pytest.mark.parametrize(["service_method", "wrapper_class", "value"], test_cases)
 async def test_service_unwraps_response(
-    service_method: Callable[[TestStub], Any], wrapper_class: Callable, value
+    service_method: Callable[[TestStub, Input], Any], wrapper_class: Callable, value
 ):
     """
     grpclib does not unwrap wrapper values returned by services
@@ -47,8 +56,9 @@ async def test_service_unwraps_response(
     wrapped_value = wrapper_class()
     wrapped_value.value = value
     service = TestStub(MockChannel(responses=[wrapped_value]))
+    method_param = Input()
 
-    response_value = await service_method(service)
+    response_value = await service_method(service, method_param)
 
     assert response_value == value
     assert type(response_value) == type(value)

tests/inputs/googletypes_response_embedded/googletypes_response_embedded.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes_response_embedded;
+
 import "google/protobuf/wrappers.proto";
 
 // Tests that wrapped values are supported as part of output message

tests/inputs/googletypes_response_embedded/test_googletypes_response_embedded.py

@@ -2,6 +2,7 @@ import pytest
 
 from tests.mocks import MockChannel
 from tests.output_betterproto.googletypes_response_embedded import (
+    Input,
     Output,
     TestStub,
 )
@@ -26,7 +27,7 @@ async def test_service_passes_through_unwrapped_values_embedded_in_response():
     )
 
     service = TestStub(MockChannel(responses=[output]))
-    response = await service.get_output()
+    response = await service.get_output(Input())
 
     assert response.double_value == 10.0
     assert response.float_value == 12.0

tests/inputs/googletypes_service_returns_empty/googletypes_service_returns_empty.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes_service_returns_empty;
+
 import "google/protobuf/empty.proto";
 
 service Test {

tests/inputs/googletypes_service_returns_googletype/googletypes_service_returns_googletype.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes_service_returns_googletype;
+
 import "google/protobuf/empty.proto";
 import "google/protobuf/struct.proto";
 

tests/inputs/googletypes_struct/googletypes_struct.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes_struct;
+
 import "google/protobuf/struct.proto";
 
 message Test {

tests/inputs/googletypes_value/googletypes_value.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package googletypes_value;
+
 import "google/protobuf/struct.proto";
 
 // Tests that fields of type google.protobuf.Value can contain arbitrary JSON-values.

tests/inputs/import_capitalized_package/capitalized.proto

@@ -1,7 +1,7 @@
 syntax = "proto3";
 
 
-package Capitalized;
+package import_capitalized_package.Capitalized;
 
 message Message {
 

tests/inputs/import_capitalized_package/test.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package import_capitalized_package;
+
 import "capitalized.proto";
 
 // Tests that we can import from a package with a capital name, that looks like a nested type, but isn't.

tests/inputs/import_child_package_from_package/child.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 
-package package.childpackage;
+package import_child_package_from_package.package.childpackage;
 
 message ChildMessage {
 

tests/inputs/import_child_package_from_package/import_child_package_from_package.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package import_child_package_from_package;
+
 import "package_message.proto";
 
 // Tests generated imports when a message in a package refers to a message in a nested child package.

tests/inputs/import_child_package_from_package/package_message.proto

@@ -2,7 +2,7 @@ syntax = "proto3";
 
 import "child.proto";
 
-package package;
+package import_child_package_from_package.package;
 
 message PackageMessage {
     package.childpackage.ChildMessage c = 1;

tests/inputs/import_child_package_from_root/child.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 
-package childpackage;
+package import_child_package_from_root.childpackage;
 
 message Message {
 

tests/inputs/import_child_package_from_root/import_child_package_from_root.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package import_child_package_from_root;
+
 import "child.proto";
 
 // Tests generated imports when a message in root refers to a message in a child package.

tests/inputs/import_circular_dependency/import_circular_dependency.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package import_circular_dependency;
+
 import "root.proto";
 import "other.proto";
 

tests/inputs/import_circular_dependency/other.proto

@@ -1,7 +1,7 @@
 syntax = "proto3";
 
 import "root.proto";
-package other;
+package import_circular_dependency.other;
 
 message OtherPackageMessage {
     RootPackageMessage rootPackageMessage = 1;

tests/inputs/import_circular_dependency/root.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package import_circular_dependency;
+
 message RootPackageMessage {
 
 }

tests/inputs/import_cousin_package/cousin.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 
-package cousin.cousin_subpackage;
+package import_cousin_package.cousin.cousin_subpackage;
 
 message CousinMessage {
 }

tests/inputs/import_cousin_package/test.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 
-package test.subpackage;
+package import_cousin_package.test.subpackage;
 
 import "cousin.proto";
 

tests/inputs/import_cousin_package_same_name/cousin.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 
-package cousin.subpackage;
+package import_cousin_package_same_name.cousin.subpackage;
 
 message CousinMessage {
 }

tests/inputs/import_cousin_package_same_name/test.proto

@@ -1,6 +1,6 @@
 syntax = "proto3";
 
-package test.subpackage;
+package import_cousin_package_same_name.test.subpackage;
 
 import "cousin.proto";
 

tests/inputs/import_packages_same_name/import_packages_same_name.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
+package import_packages_same_name;
+
 import "users_v1.proto";
 import "posts_v1.proto";