Release v2.0.0b2 (#175)

* Implement Message.__bool__ with similar semantics to a collection, such that any value being set on the message (i.e. having a non-default value) make the Message value truthy .

Co-authored-by: nat <n@natn.me>

.github/CONTRIBUTING.md

@@ -0,0 +1,23 @@
+# Contributing
+
+There's lots to do, and we're working hard, so any help is welcome!
+
+- :speech_balloon: Join us on [Slack](https://join.slack.com/t/betterproto/shared_invite/zt-f0n0uolx-iN8gBNrkPxtKHTLpG3o1OQ)!
+
+What can you do?
+
+- :+1: Vote on [issues](https://github.com/danielgtaylor/python-betterproto/issues).
+- :speech_balloon: Give feedback on [Pull Requests](https://github.com/danielgtaylor/python-betterproto/pulls) and [Issues](https://github.com/danielgtaylor/python-betterproto/issues):
+    - Suggestions
+    - Express approval
+    - Raise concerns
+- :small_red_triangle: Create an issue:
+    - File a bug (please check its not a duplicate)
+    - Propose an enhancement
+- :white_check_mark: Create a PR:
+    - [Creating a failing test-case](https://github.com/danielgtaylor/python-betterproto/blob/master/betterproto/tests/README.md) to make bug-fixing easier
+    - Fix any of the open issues
+        - [Good first issues](https://github.com/danielgtaylor/python-betterproto/issues?q=is%3Aissue+is%3Aopen+label%3A%22good+first+issue%22)
+        - [Issues with tests](https://github.com/danielgtaylor/python-betterproto/issues?q=is%3Aissue+is%3Aopen+label%3A%22has+test%22)
+    - New bugfix or idea
+        - If you'd like to discuss your idea first, join us on Slack!

.github/workflows/ci.yml

@@ -1,74 +1,69 @@
 name: CI
 
-on: [push, pull_request]
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '**'
 
 jobs:
-
-  check-formatting:
-    runs-on: ubuntu-latest
-
-    name: Consult black on python formatting
-
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
-        with:
-          python-version: 3.7
-      - uses: Gr1N/setup-poetry@v2
-      - uses: actions/cache@v2
-        with:
-          path: ~/.cache/pypoetry/virtualenvs
-          key: ${{ runner.os }}-poetry-${{ hashFiles('poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-poetry-
-      - name: Install dependencies
-        run: poetry install
-      - name: Run black
-        run: make check-style
-
-  run-tests:
-    runs-on: ubuntu-latest
-
-    name: Run tests with tox
-
+  tests:
+    name: ${{ matrix.os }} / ${{ matrix.python-version }}
+    runs-on: ${{ matrix.os }}-latest
     strategy:
       matrix:
-        python-version: [ '3.6', '3.7', '3.8']
-
+        os: [Ubuntu, MacOS, Windows]
+        python-version: [3.6, 3.7, 3.8, 3.9]
+        exclude:
+          - os: Windows
+            python-version: 3.6
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
-      - uses: Gr1N/setup-poetry@v2
-      - uses: actions/cache@v2
+
+      - name: Get full Python version
+        id: full-python-version
+        shell: bash
+        run: echo ::set-output name=version::$(python -c "import sys; print('-'.join(str(v) for v in sys.version_info))")
+
+      - name: Install poetry
+        shell: bash
+        run: |
+          python -m pip install poetry
+          echo "$HOME/.poetry/bin" >> $GITHUB_PATH
+
+      - name: Configure poetry
+        shell: bash
+        run: poetry config virtualenvs.in-project true
+
+      - name: Set up cache
+        uses: actions/cache@v2
+        id: cache
         with:
-          path: ~/.cache/pypoetry/virtualenvs
-          key: ${{ runner.os }}-poetry-${{ hashFiles('poetry.lock') }}
-          restore-keys: |
-            ${{ runner.os }}-poetry-
+          path: .venv
+          key: venv-${{ runner.os }}-${{ steps.full-python-version.outputs.version }}-${{ hashFiles('**/poetry.lock') }}
+
+      - name: Ensure cache is healthy
+        if: steps.cache.outputs.cache-hit == 'true'
+        shell: bash
+        run: poetry run pip --version >/dev/null 2>&1 || rm -rf .venv
+
       - name: Install dependencies
+        shell: bash
         run: |
-          sudo apt install protobuf-compiler libprotobuf-dev
+          poetry run python -m pip install pip -U
           poetry install
-      - name: Run tests
-        run: |
-          make generate
-          make test
 
-  build-release:
-    runs-on: ubuntu-latest
+      - name: Generate code from proto files
+        shell: bash
+        run: poetry run python -m tests.generate -v
 
-    steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
-        with:
-          python-version: 3.7
-      - uses: Gr1N/setup-poetry@v2
-      - name: Build package
-        run: poetry build
-      - name: Publish package to PyPI
-        if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
-        run: poetry publish -n
-        env:
-          POETRY_PYPI_TOKEN_PYPI: ${{ secrets.pypi }}
+      - name: Execute test suite
+        shell: bash
+        run: poetry run pytest tests/

.github/workflows/code-quality.yml

@@ -0,0 +1,26 @@
+name: Code Quality
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  check-formatting:
+    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

.github/workflows/release.yml

@@ -0,0 +1,31 @@
+name: Release
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - '**'
+  pull_request:
+    branches:
+      - '**'
+
+jobs:
+  packaging:
+    name: Distribution
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up Python 3.8
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.8
+      - name: Install poetry
+        run: python -m pip install poetry
+      - name: Build package
+        run: poetry build
+      - name: Publish package to PyPI
+        if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
+        env:
+          POETRY_PYPI_TOKEN_PYPI: ${{ secrets.pypi }}
+        run: poetry publish -n

.gitignore

@@ -6,7 +6,7 @@
 .pytest_cache
 .python-version
 build/
-betterproto/tests/output_*
+tests/output_*
 **/__pycache__
 dist
 **/*.egg-info
@@ -14,3 +14,6 @@ output
 .idea
 .DS_Store
 .tox
+.venv
+.asv
+venv

.readthedocs.yml

@@ -0,0 +1,17 @@
+version: 2
+formats: []
+
+build:
+  image: latest
+
+sphinx:
+  configuration: docs/conf.py
+  fail_on_warning: false
+
+python:
+  version: 3.7
+  install:
+    - method: pip
+      path: .
+      extra_requirements:
+        - dev

CHANGELOG.md

@@ -5,6 +5,53 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+- Versions suffixed with `b*` are in `beta` and can be installed with `pip install --pre betterproto`.
+
+## [2.0.0b2] - 2020-11-24
+
+- Add support for deprecated message and fields [#126](https://github.com/danielgtaylor/python-betterproto/pull/126)
+- Add support for recursive messages [#130](https://github.com/danielgtaylor/python-betterproto/pull/130)
+- Add support for `bool(Message)` [#142](https://github.com/danielgtaylor/python-betterproto/pull/142)
+- Improve support for Python 3.9 [#140](https://github.com/danielgtaylor/python-betterproto/pull/140) [#173](https://github.com/danielgtaylor/python-betterproto/pull/173)
+- Improve keyword sanitisation for generated code [#137](https://github.com/danielgtaylor/python-betterproto/pull/137)
+
+- Fix missing serialized_on_wire when message contains only lists [#81](https://github.com/danielgtaylor/python-betterproto/pull/81)
+- Fix circular dependencies [#100](https://github.com/danielgtaylor/python-betterproto/pull/100)
+- Fix to_dict enum fields when numbering is not consecutive [#102](https://github.com/danielgtaylor/python-betterproto/pull/102)
+- Fix argument generation for stub methods when using `import` with proto definition [#103](https://github.com/danielgtaylor/python-betterproto/pull/103)
+- Fix missing async/await keywords when casing [#104](https://github.com/danielgtaylor/python-betterproto/pull/104)
+- Fix mutable default arguments in generated code [#105](https://github.com/danielgtaylor/python-betterproto/pull/105)
+- Fix serialisation of default values in oneofs when calling to_dict() or to_json() [#110](https://github.com/danielgtaylor/python-betterproto/pull/110)
+- Fix static type checking for grpclib client [#124](https://github.com/danielgtaylor/python-betterproto/pull/124)
+- Fix python3.6 compatibility issue with dataclasses [#124](https://github.com/danielgtaylor/python-betterproto/pull/124)
+- Fix handling of trailer-only responses [#127](https://github.com/danielgtaylor/python-betterproto/pull/127)
+
+- Refactor plugin.py to use modular dataclasses in tree-like structure to represent parsed data [#121](https://github.com/danielgtaylor/python-betterproto/pull/121)
+- Refactor template compilation logic [#136](https://github.com/danielgtaylor/python-betterproto/pull/136)
+
+- Replace use of platform provided protoc with development dependency on grpcio-tools [#107](https://github.com/danielgtaylor/python-betterproto/pull/107)
+- Switch to using `poe` from `make` to manage project development tasks [#118](https://github.com/danielgtaylor/python-betterproto/pull/118)
+- Improve CI platform coverage [#128](https://github.com/danielgtaylor/python-betterproto/pull/128)
+
+## [2.0.0b1] - 2020-07-04
+
+[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.
+
+- Add support for gRPC  and **stream-stream** [#83](https://github.com/danielgtaylor/python-betterproto/pull/83)
+- Switch from `pipenv` to `poetry` for development [#75](https://github.com/danielgtaylor/python-betterproto/pull/75)
+- Fix two packages with the same name suffix should not cause naming conflict [#25](https://github.com/danielgtaylor/python-betterproto/issues/25)
+
+- Fix Import child package from root [#57](https://github.com/danielgtaylor/python-betterproto/issues/57)
+- Fix Import child package from package [#58](https://github.com/danielgtaylor/python-betterproto/issues/58)
+- Fix Import parent package from child package [#59](https://github.com/danielgtaylor/python-betterproto/issues/59)
+- Fix Import root package from child package [#60](https://github.com/danielgtaylor/python-betterproto/issues/60)
+- Fix Import root package from root [#61](https://github.com/danielgtaylor/python-betterproto/issues/61)
+
+- Fix ALL_CAPS message fields are parsed incorrectly. [#11](https://github.com/danielgtaylor/python-betterproto/issues/11)
+
 ## [1.2.5] - 2020-04-27
 
 - Add .j2 suffix to python template names to avoid confusing certain build tools [#72](https://github.com/danielgtaylor/python-betterproto/pull/72)

Makefile

@@ -1,42 +0,0 @@
-.PHONY: help setup generate test types format clean plugin full-test check-style
-
-help:               ## - Show this help.
-	@fgrep -h "##" $(MAKEFILE_LIST) | fgrep -v fgrep | sed -e 's/\\$$//' | sed -e 's/##//'
-
-# Dev workflow tasks
-
-generate:           ## - Generate test cases (do this once before running test)
-	poetry run ./betterproto/tests/generate.py
-
-test:               ## - Run tests
-	poetry run pytest --cov betterproto
-
-types:              ## - Check types with mypy
-	poetry run mypy betterproto --ignore-missing-imports
-
-format:             ## - Apply black formatting to source code
-	poetry run black . --exclude tests/output_
-
-clean:              ## - Clean out generated files from the workspace
-	rm -rf .coverage \
-	       .mypy_cache \
-	       .pytest_cache \
-	       dist \
-	       **/__pycache__ \
-	       betterproto/tests/output_*
-
-# Manual testing
-
-# By default write plugin output to a directory called output
-o=output
-plugin:             ## - Execute the protoc plugin, with output write to `output` or the value passed to `-o`
-	mkdir -p $(o)
-	protoc --plugin=protoc-gen-custom=betterproto/plugin.py $(i) --custom_out=$(o)
-
-# CI tasks
-
-full-test: generate ## - Run full testing sequence with multiple pythons
-	poetry run tox
-
-check-style:        ## - Check if code style is correct
-	poetry run black . --check --diff --exclude tests/output_

README.md

@@ -37,10 +37,9 @@ 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 & Getting Started
+## Installation
 
 First, install the package. Note that the `[compiler]` feature flag tells it to install extra dependencies only needed by the `protoc` plugin:
 
@@ -52,6 +51,12 @@ pip install "betterproto[compiler]"
 pip install betterproto
 ```
 
+*Betterproto* is under active development. To install the latest beta version, use `pip install --pre betterproto`.
+
+## Getting Started
+
+### Compiling proto files
+
 Now, given you installed the compiler and have a proto file, e.g `example.proto`:
 
 ```protobuf
@@ -65,13 +70,20 @@ message Greeting {
 }
 ```
 
-You can run the following:
+You can run the following to invoke protoc directly:
 
 ```sh
 mkdir lib
 protoc -I . --python_betterproto_out=lib example.proto
 ```
 
+or run the following to invoke protoc via grpcio-tools:
+
+```sh
+pip install grpcio-tools
+python -m grpc_tools.protoc -I . --python_betterproto_out=lib example.proto
+```
+
 This will generate `lib/hello/__init__.py` which looks like:
 
 ```python
@@ -120,7 +132,7 @@ Greeting(message="Hey!")
 
 The generated Protobuf `Message` classes are compatible with [grpclib](https://github.com/vmagamedov/grpclib) so you are free to use it if you like. That said, this project also includes support for async gRPC stub generation with better static type checking and code completion support. It is enabled by default.
 
-Given an example like:
+Given an example service definition:
 
 ```protobuf
 syntax = "proto3";
@@ -147,22 +159,37 @@ service Echo {
 }
 ```
 
-You can use it like so (enable async in the interactive shell first):
+A client can be implemented as follows:
+```python
+import asyncio
+import echo
 
-```py
->>> import echo
->>> from grpclib.client import Channel
+from grpclib.client import Channel
 
->>> channel = Channel(host="127.0.0.1", port=1234)
->>> service = echo.EchoStub(channel)
->>> await service.echo(value="hello", extra_times=1)
-EchoResponse(values=["hello", "hello"])
 
->>> async for response in service.echo_stream(value="hello", extra_times=1)
+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)
+    print(response)
+
+    async for response in service.echo_stream(value="hello", extra_times=1):
         print(response)
 
-EchoStreamResponse(value="hello")
-EchoStreamResponse(value="hello")
+    # don't forget to close the channel when done!
+    channel.close()
+
+
+if __name__ == "__main__":
+    loop = asyncio.get_event_loop()
+    loop.run_until_complete(main())
+
+```
+which would output
+```python
+EchoResponse(values=['hello', 'hello'])
+EchoStreamResponse(value='hello')
+EchoStreamResponse(value='hello')
 ```
 
 ### JSON
@@ -174,8 +201,8 @@ Both serializing and parsing are supported to/from JSON and Python dictionaries
 
 For compatibility the default is to convert field names to `camelCase`. You can control this behavior by passing a casing value, e.g:
 
-```py
->>> MyMessage().to_dict(casing=betterproto.Casing.SNAKE)
+```python
+MyMessage().to_dict(casing=betterproto.Casing.SNAKE)
 ```
 
 ### Determining if a message was sent
@@ -298,20 +325,31 @@ datetime.datetime(2019, 1, 1, 11, 59, 58, 800000, tzinfo=datetime.timezone.utc)
 
 ## Development
 
-Join us on [Slack](https://join.slack.com/t/betterproto/shared_invite/zt-f0n0uolx-iN8gBNrkPxtKHTLpG3o1OQ)!
+- _Join us on [Slack](https://join.slack.com/t/betterproto/shared_invite/zt-f0n0uolx-iN8gBNrkPxtKHTLpG3o1OQ)!_
+- _See how you can help → [Contributing](.github/CONTRIBUTING.md)_
 
-First, make sure you have Python 3.6+ and `poetry` installed, along with the official [Protobuf Compiler](https://github.com/protocolbuffers/protobuf/releases) for your platform. Then:
+### Requirements
+
+- Python (3.6 or higher)
+
+- [poetry](https://python-poetry.org/docs/#installation)
+  *Needed to install dependencies in a virtual environment*
+
+- [poethepoet](https://github.com/nat-n/poethepoet) for running development tasks as defined in pyproject.toml
+  - Can be installed to your host environment via `pip install poethepoet` then executed as simple `poe`
+  - or run from the poetry venv as `poetry run poe`
+
+### Setup
 
 ```sh
 # Get set up with the virtual env & dependencies
+poetry run pip install --upgrade pip
 poetry install
 
 # Activate the poetry environment
 poetry shell
 ```
 
-To benefit from the collection of standard development tasks ensure you have make installed and run `make help` to see available tasks.
-
 ### Code style
 
 This project enforces [black](https://github.com/psf/black) python code formatting.
@@ -319,7 +357,7 @@ This project enforces [black](https://github.com/psf/black) python code formatti
 Before committing changes run:
 
 ```sh
-make format
+poe format
 ```
 
 To avoid merge conflicts later, non-black formatted python code will fail in CI.
@@ -353,15 +391,15 @@ Here's how to run the tests.
 
 ```sh
 # Generate assets from sample .proto files required by the tests
-make generate
+poe generate
 # Run the tests
-make test
+poe test
 ```
 
 To run tests as they are run in CI (with tox) run:
 
 ```sh
-make full-test
+poe full-test
 ```
 
 ### (Re)compiling Google Well-known Types
@@ -382,7 +420,6 @@ protoc \
     /usr/local/include/google/protobuf/*.proto
 ```
 
-
 ### TODO
 
 - [x] Fixed length fields
@@ -413,10 +450,10 @@ protoc \
   - [x] Enum strings
   - [x] Well known types support (timestamp, duration, wrappers)
   - [x] Support different casing (orig vs. camel vs. others?)
-- [ ] Async service stubs
+- [x] Async service stubs
   - [x] Unary-unary
   - [x] Server streaming response
-  - [ ] Client streaming request
+  - [x] Client streaming request
 - [x] Renaming messages and fields to conform to Python name standards
 - [x] Renaming clashes with language keywords
 - [x] Python package

asv.conf.json

@@ -0,0 +1,157 @@
+{
+    // The version of the config file format.  Do not change, unless
+    // you know what you are doing.
+    "version": 1,
+
+    // The name of the project being benchmarked
+    "project": "python-betterproto",
+
+    // The project's homepage
+    "project_url": "https://github.com/danielgtaylor/python-betterproto",
+
+    // The URL or local path of the source code repository for the
+    // project being benchmarked
+    "repo": ".",
+
+    // The Python project's subdirectory in your repo.  If missing or
+    // the empty string, the project is assumed to be located at the root
+    // of the repository.
+    // "repo_subdir": "",
+
+    // Customizable commands for building, installing, and
+    // uninstalling the project. See asv.conf.json documentation.
+    //
+    "install_command": ["python -m pip install ."],
+    "uninstall_command": ["return-code=any python -m pip uninstall -y {project}"],
+    "build_command": ["python -m pip wheel -w {build_cache_dir} {build_dir}"],
+
+    // List of branches to benchmark. If not provided, defaults to "master"
+    // (for git) or "default" (for mercurial).
+    // "branches": ["master"], // for git
+    // "branches": ["default"],    // for mercurial
+
+    // The DVCS being used.  If not set, it will be automatically
+    // determined from "repo" by looking at the protocol in the URL
+    // (if remote), or by looking for special directories, such as
+    // ".git" (if local).
+    // "dvcs": "git",
+
+    // The tool to use to create environments.  May be "conda",
+    // "virtualenv" or other value depending on the plugins in use.
+    // If missing or the empty string, the tool will be automatically
+    // determined by looking for tools on the PATH environment
+    // variable.
+    "environment_type": "virtualenv",
+
+    // timeout in seconds for installing any dependencies in environment
+    // defaults to 10 min
+    //"install_timeout": 600,
+
+    // the base URL to show a commit for the project.
+    // "show_commit_url": "http://github.com/owner/project/commit/",
+
+    // The Pythons you'd like to test against.  If not provided, defaults
+    // to the current version of Python used to run `asv`.
+    // "pythons": ["2.7", "3.6"],
+
+    // The list of conda channel names to be searched for benchmark
+    // dependency packages in the specified order
+    // "conda_channels": ["conda-forge", "defaults"],
+
+    // The matrix of dependencies to test.  Each key is the name of a
+    // package (in PyPI) and the values are version numbers.  An empty
+    // list or empty string indicates to just test against the default
+    // (latest) version. null indicates that the package is to not be
+    // installed. If the package to be tested is only available from
+    // PyPi, and the 'environment_type' is conda, then you can preface
+    // the package name by 'pip+', and the package will be installed via
+    // pip (with all the conda available packages installed first,
+    // followed by the pip installed packages).
+    //
+    // "matrix": {
+    //     "numpy": ["1.6", "1.7"],
+    //     "six": ["", null],        // test with and without six installed
+    //     "pip+emcee": [""],   // emcee is only available for install with pip.
+    // },
+
+    // Combinations of libraries/python versions can be excluded/included
+    // from the set to test. Each entry is a dictionary containing additional
+    // key-value pairs to include/exclude.
+    //
+    // An exclude entry excludes entries where all values match. The
+    // values are regexps that should match the whole string.
+    //
+    // An include entry adds an environment. Only the packages listed
+    // are installed. The 'python' key is required. The exclude rules
+    // do not apply to includes.
+    //
+    // In addition to package names, the following keys are available:
+    //
+    // - python
+    //     Python version, as in the *pythons* variable above.
+    // - environment_type
+    //     Environment type, as above.
+    // - sys_platform
+    //     Platform, as in sys.platform. Possible values for the common
+    //     cases: 'linux2', 'win32', 'cygwin', 'darwin'.
+    //
+    // "exclude": [
+    //     {"python": "3.2", "sys_platform": "win32"}, // skip py3.2 on windows
+    //     {"environment_type": "conda", "six": null}, // don't run without six on conda
+    // ],
+    //
+    // "include": [
+    //     // additional env for python2.7
+    //     {"python": "2.7", "numpy": "1.8"},
+    //     // additional env if run on windows+conda
+    //     {"platform": "win32", "environment_type": "conda", "python": "2.7", "libpython": ""},
+    // ],
+
+    // The directory (relative to the current directory) that benchmarks are
+    // stored in.  If not provided, defaults to "benchmarks"
+    // "benchmark_dir": "benchmarks",
+
+    // The directory (relative to the current directory) to cache the Python
+    // environments in.  If not provided, defaults to "env"
+    "env_dir": ".asv/env",
+
+    // The directory (relative to the current directory) that raw benchmark
+    // results are stored in.  If not provided, defaults to "results".
+    "results_dir": ".asv/results",
+
+    // The directory (relative to the current directory) that the html tree
+    // should be written to.  If not provided, defaults to "html".
+    "html_dir": ".asv/html",
+
+    // The number of characters to retain in the commit hashes.
+    // "hash_length": 8,
+
+    // `asv` will cache results of the recent builds in each
+    // environment, making them faster to install next time.  This is
+    // the number of builds to keep, per environment.
+    // "build_cache_size": 2,
+
+    // The commits after which the regression search in `asv publish`
+    // should start looking for regressions. Dictionary whose keys are
+    // regexps matching to benchmark names, and values corresponding to
+    // the commit (exclusive) after which to start looking for
+    // regressions.  The default is to start from the first commit
+    // with results. If the commit is `null`, regression detection is
+    // skipped for the matching benchmark.
+    //
+    // "regressions_first_commits": {
+    //    "some_benchmark": "352cdf",  // Consider regressions only after this commit
+    //    "another_benchmark": null,   // Skip regression detection altogether
+    // },
+
+    // The thresholds for relative change in results, after which `asv
+    // publish` starts reporting regressions. Dictionary of the same
+    // form as in ``regressions_first_commits``, with values
+    // indicating the thresholds.  If multiple entries match, the
+    // maximum is taken. If no entry matches, the default is 5%.
+    //
+    // "regressions_thresholds": {
+    //    "some_benchmark": 0.01,     // Threshold of 1%
+    //    "another_benchmark": 0.5,   // Threshold of 50%
+    // },
+}

benchmarks/__init__.py

@@ -0,0 +1 @@
+

benchmarks/benchmarks.py

@@ -0,0 +1,59 @@
+import betterproto
+from dataclasses import dataclass
+
+
+@dataclass
+class TestMessage(betterproto.Message):
+    foo: int = betterproto.uint32_field(0)
+    bar: str = betterproto.string_field(1)
+    baz: float = betterproto.float_field(2)
+
+
+class BenchMessage:
+    """Test creation and usage a proto message."""
+
+    def setup(self):
+        self.cls = TestMessage
+        self.instance = TestMessage()
+        self.instance_filled = TestMessage(0, "test", 0.0)
+
+    def time_overhead(self):
+        """Overhead in class definition."""
+
+        @dataclass
+        class Message(betterproto.Message):
+            foo: int = betterproto.uint32_field(0)
+            bar: str = betterproto.string_field(1)
+            baz: float = betterproto.float_field(2)
+
+    def time_instantiation(self):
+        """Time instantiation"""
+        self.cls()
+
+    def time_attribute_access(self):
+        """Time to access an attribute"""
+        self.instance.foo
+        self.instance.bar
+        self.instance.baz
+
+    def time_init_with_values(self):
+        """Time to set an attribute"""
+        self.cls(0, "test", 0.0)
+
+    def time_attribute_setting(self):
+        """Time to set attributes"""
+        self.instance.foo = 0
+        self.instance.bar = "test"
+        self.instance.baz = 0.0
+
+    def time_serialize(self):
+        """Time serializing a message to wire."""
+        bytes(self.instance_filled)
+
+
+class MemSuite:
+    def setup(self):
+        self.cls = TestMessage
+
+    def mem_instance(self):
+        return self.cls()

betterproto/plugin.bat

@@ -1,2 +0,0 @@
-@SET plugin_dir=%~dp0
-@python %plugin_dir%/plugin.py %*

betterproto/plugin.py

@@ -1,403 +0,0 @@
-#!/usr/bin/env python
-
-import itertools
-import os.path
-import pathlib
-import re
-import sys
-import textwrap
-from typing import List, Union
-
-import betterproto
-from betterproto.compile.importing import get_type_reference
-from betterproto.compile.naming import (
-    pythonize_class_name,
-    pythonize_field_name,
-    pythonize_method_name,
-)
-
-try:
-    # betterproto[compiler] specific dependencies
-    import black
-    from google.protobuf.compiler import plugin_pb2 as plugin
-    from google.protobuf.descriptor_pb2 import (
-        DescriptorProto,
-        EnumDescriptorProto,
-        FieldDescriptorProto,
-    )
-    import google.protobuf.wrappers_pb2 as google_wrappers
-    import jinja2
-except ImportError as err:
-    missing_import = err.args[0][17:-1]
-    print(
-        "\033[31m"
-        f"Unable to import `{missing_import}` 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)
-
-
-def py_type(package: str, imports: set, field: FieldDescriptorProto) -> str:
-    if field.type in [1, 2]:
-        return "float"
-    elif field.type in [3, 4, 5, 6, 7, 13, 15, 16, 17, 18]:
-        return "int"
-    elif field.type == 8:
-        return "bool"
-    elif field.type == 9:
-        return "str"
-    elif field.type in [11, 14]:
-        # Type referencing another defined Message or a named enum
-        return get_type_reference(package, imports, field.type_name)
-    elif field.type == 12:
-        return "bytes"
-    else:
-        raise NotImplementedError(f"Unknown type {field.type}")
-
-
-def get_py_zero(type_num: int) -> Union[str, float]:
-    zero: Union[str, float] = 0
-    if type_num in []:
-        zero = 0.0
-    elif type_num == 8:
-        zero = "False"
-    elif type_num == 9:
-        zero = '""'
-    elif type_num == 11:
-        zero = "None"
-    elif type_num == 12:
-        zero = 'b""'
-
-    return zero
-
-
-def traverse(proto_file):
-    def _traverse(path, items, prefix=""):
-        for i, item in enumerate(items):
-            # Adjust the name since we flatten the heirarchy.
-            item.name = next_prefix = 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]
-
-                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)
-    )
-
-
-def get_comment(proto_file, path: List[int], indent: int = 4) -> str:
-    pad = " " * indent
-    for sci in proto_file.source_code_info.location:
-        # print(list(sci.path), path, file=sys.stderr)
-        if list(sci.path) == path and sci.leading_comments:
-            lines = textwrap.wrap(
-                sci.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)
-            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}"""'
-
-    return ""
-
-
-def generate_code(request, response):
-    plugin_options = request.parameter.split(",") if request.parameter else []
-
-    env = jinja2.Environment(
-        trim_blocks=True,
-        lstrip_blocks=True,
-        loader=jinja2.FileSystemLoader("%s/templates/" % os.path.dirname(__file__)),
-    )
-    template = env.get_template("template.py.j2")
-
-    output_map = {}
-    for proto_file in request.proto_file:
-        if (
-            proto_file.package == "google.protobuf"
-            and "INCLUDE_GOOGLE" not in plugin_options
-        ):
-            continue
-
-        output_file = str(pathlib.Path(*proto_file.package.split("."), "__init__.py"))
-
-        if output_file not in output_map:
-            output_map[output_file] = {"package": proto_file.package, "files": []}
-        output_map[output_file]["files"].append(proto_file)
-
-    # TODO: Figure out how to handle gRPC request/response messages and add
-    # processing below for Service.
-
-    for filename, options in output_map.items():
-        package = options["package"]
-        # print(package, filename, file=sys.stderr)
-        output = {
-            "package": package,
-            "files": [f.name for f in options["files"]],
-            "imports": set(),
-            "datetime_imports": set(),
-            "typing_imports": set(),
-            "messages": [],
-            "enums": [],
-            "services": [],
-        }
-
-        for proto_file in options["files"]:
-            item: DescriptorProto
-            for item, path in traverse(proto_file):
-                data = {"name": item.name, "py_name": pythonize_class_name(item.name)}
-
-                if isinstance(item, DescriptorProto):
-                    # print(item, file=sys.stderr)
-                    if item.options.map_entry:
-                        # Skip generated map entry messages since we just use dicts
-                        continue
-
-                    data.update(
-                        {
-                            "type": "Message",
-                            "comment": get_comment(proto_file, path),
-                            "properties": [],
-                        }
-                    )
-
-                    for i, f in enumerate(item.field):
-                        t = py_type(package, output["imports"], f)
-                        zero = get_py_zero(f.type)
-
-                        repeated = False
-                        packed = False
-
-                        field_type = f.Type.Name(f.type).lower()[5:]
-
-                        field_wraps = ""
-                        match_wrapper = re.match(
-                            r"\.google\.protobuf\.(.+)Value", f.type_name
-                        )
-                        if match_wrapper:
-                            wrapped_type = "TYPE_" + match_wrapper.group(1).upper()
-                            if hasattr(betterproto, wrapped_type):
-                                field_wraps = f"betterproto.{wrapped_type}"
-
-                        map_types = None
-                        if f.type == 11:
-                            # This might be a map...
-                            message_type = f.type_name.split(".").pop().lower()
-                            # message_type = py_type(package)
-                            map_entry = f"{f.name.replace('_', '').lower()}entry"
-
-                            if message_type == map_entry:
-                                for nested in item.nested_type:
-                                    if (
-                                        nested.name.replace("_", "").lower()
-                                        == map_entry
-                                    ):
-                                        if nested.options.map_entry:
-                                            # print("Found a map!", file=sys.stderr)
-                                            k = py_type(
-                                                package,
-                                                output["imports"],
-                                                nested.field[0],
-                                            )
-                                            v = py_type(
-                                                package,
-                                                output["imports"],
-                                                nested.field[1],
-                                            )
-                                            t = f"Dict[{k}, {v}]"
-                                            field_type = "map"
-                                            map_types = (
-                                                f.Type.Name(nested.field[0].type),
-                                                f.Type.Name(nested.field[1].type),
-                                            )
-                                            output["typing_imports"].add("Dict")
-
-                        if f.label == 3 and field_type != "map":
-                            # Repeated field
-                            repeated = True
-                            t = f"List[{t}]"
-                            zero = "[]"
-                            output["typing_imports"].add("List")
-
-                            if f.type in [1, 2, 3, 4, 5, 6, 7, 8, 13, 15, 16, 17, 18]:
-                                packed = True
-
-                        one_of = ""
-                        if f.HasField("oneof_index"):
-                            one_of = item.oneof_decl[f.oneof_index].name
-
-                        if "Optional[" in t:
-                            output["typing_imports"].add("Optional")
-
-                        if "timedelta" in t:
-                            output["datetime_imports"].add("timedelta")
-                        elif "datetime" in t:
-                            output["datetime_imports"].add("datetime")
-
-                        data["properties"].append(
-                            {
-                                "name": f.name,
-                                "py_name": pythonize_field_name(f.name),
-                                "number": f.number,
-                                "comment": get_comment(proto_file, path + [2, i]),
-                                "proto_type": int(f.type),
-                                "field_type": field_type,
-                                "field_wraps": field_wraps,
-                                "map_types": map_types,
-                                "type": t,
-                                "zero": zero,
-                                "repeated": repeated,
-                                "packed": packed,
-                                "one_of": one_of,
-                            }
-                        )
-                        # print(f, file=sys.stderr)
-
-                    output["messages"].append(data)
-                elif isinstance(item, EnumDescriptorProto):
-                    # print(item.name, path, file=sys.stderr)
-                    data.update(
-                        {
-                            "type": "Enum",
-                            "comment": get_comment(proto_file, path),
-                            "entries": [
-                                {
-                                    "name": v.name,
-                                    "value": v.number,
-                                    "comment": get_comment(proto_file, path + [2, i]),
-                                }
-                                for i, v in enumerate(item.value)
-                            ],
-                        }
-                    )
-
-                    output["enums"].append(data)
-
-            for i, service in enumerate(proto_file.service):
-                # print(service, file=sys.stderr)
-
-                data = {
-                    "name": service.name,
-                    "py_name": pythonize_class_name(service.name),
-                    "comment": get_comment(proto_file, [6, i]),
-                    "methods": [],
-                }
-
-                for j, method in enumerate(service.method):
-                    input_message = None
-                    input_type = get_type_reference(
-                        package, output["imports"], method.input_type
-                    ).strip('"')
-                    for msg in output["messages"]:
-                        if msg["name"] == input_type:
-                            input_message = msg
-                            for field in msg["properties"]:
-                                if field["zero"] == "None":
-                                    output["typing_imports"].add("Optional")
-                            break
-
-                    data["methods"].append(
-                        {
-                            "name": method.name,
-                            "py_name": pythonize_method_name(method.name),
-                            "comment": get_comment(proto_file, [6, i, 2, j], indent=8),
-                            "route": f"/{package}.{service.name}/{method.name}",
-                            "input": get_type_reference(
-                                package, output["imports"], method.input_type
-                            ).strip('"'),
-                            "input_message": input_message,
-                            "output": get_type_reference(
-                                package,
-                                output["imports"],
-                                method.output_type,
-                                unwrap=False,
-                            ).strip('"'),
-                            "client_streaming": method.client_streaming,
-                            "server_streaming": method.server_streaming,
-                        }
-                    )
-
-                    if method.client_streaming:
-                        output["typing_imports"].add("AsyncIterable")
-                        output["typing_imports"].add("Iterable")
-                        output["typing_imports"].add("Union")
-                    if method.server_streaming:
-                        output["typing_imports"].add("AsyncIterator")
-
-                output["services"].append(data)
-
-        output["imports"] = sorted(output["imports"])
-        output["datetime_imports"] = sorted(output["datetime_imports"])
-        output["typing_imports"] = sorted(output["typing_imports"])
-
-        # Fill response
-        f = response.file.add()
-        f.name = filename
-
-        # Render and then format the output file.
-        f.content = black.format_str(
-            template.render(description=output),
-            mode=black.FileMode(target_versions=set([black.TargetVersion.PY37])),
-        )
-
-    # Make each output directory a package with __init__ file
-    output_paths = set(pathlib.Path(path) for path in output_map.keys())
-    init_files = (
-        set(
-            directory.joinpath("__init__.py")
-            for path in output_paths
-            for directory in path.parents
-        )
-        - output_paths
-    )
-
-    for init_file in init_files:
-        init = response.file.add()
-        init.name = str(init_file)
-
-    for filename in sorted(output_paths.union(init_files)):
-        print(f"Writing {filename}", file=sys.stderr)
-
-
-def main():
-    """The plugin's main entry point."""
-    # Read request message from stdin
-    data = sys.stdin.buffer.read()
-
-    # Parse request
-    request = plugin.CodeGeneratorRequest()
-    request.ParseFromString(data)
-
-    # Create response
-    response = plugin.CodeGeneratorResponse()
-
-    # Generate code
-    generate_code(request, response)
-
-    # Serialise response message
-    output = response.SerializeToString()
-
-    # Write to stdout
-    sys.stdout.buffer.write(output)
-
-
-if __name__ == "__main__":
-    main()

betterproto/templates/template.py.j2

@@ -1,135 +0,0 @@
-# Generated by the protocol buffer compiler.  DO NOT EDIT!
-# sources: {{ ', '.join(description.files) }}
-# plugin: python-betterproto
-from dataclasses import dataclass
-{% if description.datetime_imports %}
-from datetime import {% for i in description.datetime_imports %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
-
-{% endif%}
-{% if description.typing_imports %}
-from typing import {% for i in description.typing_imports %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
-
-{% endif %}
-
-import betterproto
-{% if description.services %}
-import grpclib
-{% endif %}
-
-{% for i in description.imports %}
-{{ i }}
-{% endfor %}
-
-
-{% if description.enums %}{% for enum in description.enums %}
-class {{ enum.py_name }}(betterproto.Enum):
-    {% if enum.comment %}
-{{ enum.comment }}
-
-    {% endif %}
-    {% for entry in enum.entries %}
-        {% if entry.comment %}
-{{ entry.comment }}
-        {% endif %}
-    {{ entry.name }} = {{ entry.value }}
-    {% endfor %}
-
-
-{% endfor %}
-{% endif %}
-{% for message in description.messages %}
-@dataclass
-class {{ message.py_name }}(betterproto.Message):
-    {% if message.comment %}
-{{ message.comment }}
-
-    {% endif %}
-    {% for field in message.properties %}
-        {% if field.comment %}
-{{ field.comment }}
-        {% endif %}
-    {{ field.py_name }}: {{ field.type }} = betterproto.{{ field.field_type }}_field({{ field.number }}{% if field.field_type == 'map'%}, betterproto.{{ field.map_types[0] }}, betterproto.{{ field.map_types[1] }}{% endif %}{% if field.one_of %}, group="{{ field.one_of }}"{% endif %}{% if field.field_wraps %}, wraps={{ field.field_wraps }}{% endif %})
-    {% endfor %}
-    {% if not message.properties %}
-    pass
-    {% endif %}
-
-
-{% endfor %}
-{% for service in description.services %}
-class {{ service.py_name }}Stub(betterproto.ServiceStub):
-    {% if service.comment %}
-{{ service.comment }}
-
-    {% endif %}
-    {% for method in service.methods %}
-    async def {{ method.py_name }}(self
-        {%- if not method.client_streaming -%}
-            {%- if method.input_message and method.input_message.properties -%}, *,
-                {%- for field in method.input_message.properties -%}
-                    {{ field.py_name }}: {% if field.zero == "None" and not field.type.startswith("Optional[") -%}
-                                            Optional[{{ field.type }}]
-                                         {%- else -%}
-                                            {{ field.type }}
-                                         {%- endif -%} = {{ field.zero }}
-                    {%- if not loop.last %}, {% endif -%}
-                {%- endfor -%}
-            {%- endif -%}
-        {%- else -%}
-            {# Client streaming: need a request iterator instead #}
-            , request_iterator: Union[AsyncIterable["{{ method.input }}"], Iterable["{{ method.input }}"]]
-        {%- endif -%}
-            ) -> {% if method.server_streaming %}AsyncIterator[{{ method.output }}]{% else %}{{ method.output }}{% endif %}:
-        {% if method.comment %}
-{{ method.comment }}
-
-        {% endif %}
-        {% if not method.client_streaming %}
-        request = {{ method.input }}()
-        {% for field in method.input_message.properties %}
-            {% 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.input }},
-            {{ method.output }},
-        ):
-            yield response
-            {% else %}{# i.e. not client streaming #}
-        async for response in self._unary_stream(
-            "{{ method.route }}",
-            request,
-            {{ method.output }},
-        ):
-            yield response
-
-            {% endif %}{# if client streaming #}
-        {% else %}{# i.e. not server streaming #}
-            {% if method.client_streaming %}
-        return await self._stream_unary(
-            "{{ method.route }}",
-            request_iterator,
-            {{ method.input }},
-            {{ method.output }}
-        )
-            {% else %}{# i.e. not client streaming #}
-        return await self._unary_unary(
-            "{{ method.route }}",
-            request,
-            {{ method.output }}
-        )
-            {% endif %}{# client streaming #}
-        {% endif %}
-
-    {% endfor %}
-{% endfor %}

betterproto/tests/inputs/enum_skipped_value/enum_skipped_value.proto

@@ -1,12 +0,0 @@
-syntax = "proto3";
-
-message Test {
-  enum MyEnum {
-    ZERO = 0;
-    ONE = 1;
-    // TWO = 2;
-    THREE = 3;
-    FOUR = 4;
-  }
-  MyEnum x = 1;
-}

betterproto/tests/inputs/enum_skipped_value/test_enum_skipped_value.py

@@ -1,18 +0,0 @@
-from betterproto.tests.output_betterproto.enum_skipped_value import (
-    Test,
-    TestMyEnum,
-)
-import pytest
-
-
-@pytest.mark.xfail(reason="#93")
-def test_message_attributes():
-    assert (
-        Test(x=TestMyEnum.ONE).to_dict()["x"] == "ONE"
-    ), "MyEnum.ONE is not serialized to 'ONE'"
-    assert (
-        Test(x=TestMyEnum.THREE).to_dict()["x"] == "THREE"
-    ), "MyEnum.THREE is not serialized to 'THREE'"
-    assert (
-        Test(x=TestMyEnum.FOUR).to_dict()["x"] == "FOUR"
-    ), "MyEnum.FOUR is not serialized to 'FOUR'"

betterproto/tests/inputs/enums/enums.json

@@ -1,3 +0,0 @@
-{
-  "greeting": "HEY"
-}

betterproto/tests/inputs/enums/enums.proto

@@ -1,14 +0,0 @@
-syntax = "proto3";
-
-// Enum for the different greeting types
-enum Greeting {
-  HI = 0;
-  HEY = 1;
-  // Formal greeting
-  HELLO = 2;
-}
-
-message Test {
-  // Greeting enum example
-  Greeting greeting = 1;
-}

betterproto/tests/inputs/import_service_input_message/import_service_input_message.proto

@@ -1,15 +0,0 @@
-syntax = "proto3";
-
-import "request_message.proto";
-
-// Tests generated service correctly imports the RequestMessage
-
-service Test {
-    rpc DoThing (RequestMessage) returns (RequestResponse);
-}
-
-
-message RequestResponse {
-    int32 value = 1;
-}
-

betterproto/tests/inputs/import_service_input_message/test_import_service.py

@@ -1,16 +0,0 @@
-import pytest
-
-from betterproto.tests.mocks import MockChannel
-from betterproto.tests.output_betterproto.import_service_input_message import (
-    RequestResponse,
-    TestStub,
-)
-
-
-@pytest.mark.xfail(reason="#68 Request Input Messages are not imported for service")
-@pytest.mark.asyncio
-async def test_service_correctly_imports_reference_message():
-    mock_response = RequestResponse(value=10)
-    service = TestStub(MockChannel([mock_response]))
-    response = await service.do_thing()
-    assert mock_response == response

docs/api.rst

@@ -0,0 +1,31 @@
+.. currentmodule:: betterproto
+
+API reference
+=============
+
+The following document outlines betterproto's api. **None** of these classes should be
+extended by the user manually.
+
+
+Message
+--------
+
+.. autoclass:: betterproto.Message
+    :members:
+    :special-members: __bytes__, __bool__
+
+
+.. autofunction:: betterproto.serialized_on_wire
+
+.. autofunction:: betterproto.which_one_of
+
+
+Enumerations
+-------------
+
+.. autoclass:: betterproto.Enum()
+    :members:
+
+
+.. autoclass:: betterproto.Casing()
+    :members:

docs/conf.py

@@ -0,0 +1,60 @@
+# Configuration file for the Sphinx documentation builder.
+#
+# This file only contains a selection of the most common options. For a full
+# list see the documentation:
+# https://www.sphinx-doc.org/en/master/usage/configuration.html
+
+# If extensions (or modules to document with autodoc) are in another directory,
+# add these directories to sys.path here. If the directory is relative to the
+# documentation root, use os.path.abspath to make it absolute, like shown here.
+
+import pathlib
+
+import toml
+
+
+# -- Project information -----------------------------------------------------
+
+project = "betterproto"
+copyright = "2019 Daniel G. Taylor"
+author = "danielgtaylor"
+pyproject = toml.load(open(pathlib.Path(__file__).parent.parent / "pyproject.toml"))
+
+
+# The full version, including alpha/beta/rc tags.
+release = pyproject["tool"]["poetry"]["version"]
+
+
+# -- General configuration ---------------------------------------------------
+
+# Add any Sphinx extension module names here, as strings. They can be
+# extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
+# ones.
+extensions = [
+    "sphinx.ext.autodoc",
+    "sphinx.ext.intersphinx",
+    "sphinx.ext.napoleon",
+]
+
+autodoc_member_order = "bysource"
+autodoc_typehints = "none"
+
+extlinks = {
+    "issue": ("https://github.com/danielgtaylor/python-betterproto/issues/%s", "GH-"),
+}
+
+# Links used for cross-referencing stuff in other documentation
+intersphinx_mapping = {
+    "py": ("https://docs.python.org/3", None),
+}
+
+
+# -- Options for HTML output -------------------------------------------------
+
+# The name of the Pygments (syntax highlighting) style to use.
+pygments_style = "friendly"
+
+# The theme to use for HTML and HTML Help pages.  See the documentation for
+# a list of builtin themes.
+
+html_theme = "sphinx_rtd_theme"

docs/index.rst

@@ -0,0 +1,33 @@
+Welcome to betterproto's documentation!
+=======================================
+
+betterproto is a protobuf compiler and interpreter. It improves the experience of using
+Protobuf and gRPC in Python, by generating readable, understandable, and idiomatic
+Python code, using modern language features.
+
+
+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
+- Generates modern, readable, idiomatic python code
+
+Contents:
+~~~~~~~~~
+
+.. toctree::
+    :maxdepth: 2
+
+    quick-start
+    api
+    migrating
+
+
+If you still can't find what you're looking for, try in one of the following pages:
+
+* :ref:`genindex`
+* :ref:`modindex`
+* :ref:`search`

docs/migrating.rst

@@ -0,0 +1,157 @@
+Migrating Guide
+===============
+
+Google's protocolbuffers
+------------------------
+
+betterproto has a mostly 1 to 1 drop in replacement for Google's protocolbuffers (after
+regenerating your protobufs of course) although there are some minor differences.
+
+.. note::
+
+    betterproto implements the same basic methods including:
+
+        - :meth:`betterproto.Message.FromString`
+        - :meth:`betterproto.Message.SerializeToString`
+
+    for compatibility purposes, however it is important to note that these are
+    effectively aliases for :meth:`betterproto.Message.parse` and
+    :meth:`betterproto.Message.__bytes__` respectively.
+
+
+Determining if a message was sent
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Sometimes it is useful to be able to determine whether a message has been sent on
+the wire. This is how the Google wrapper types work to let you know whether a value is
+unset (set as the default/zero value), or set as something else, for example.
+
+Use ``betterproto.serialized_on_wire(message)`` to determine if it was sent. This is
+a little bit different from the official Google generated Python code, and it lives
+outside the generated ``Message`` class to prevent name clashes. Note that it only
+supports Proto 3 and thus can only be used to check if ``Message`` fields are set.
+You cannot check if a scalar was sent on the wire.
+
+.. code-block:: python
+
+    # Old way (official Google Protobuf package)
+    >>> mymessage.HasField('myfield')
+    True
+
+    # New way (this project)
+    >>> betterproto.serialized_on_wire(mymessage.myfield)
+    True
+
+
+One-of Support
+~~~~~~~~~~~~~~
+
+Protobuf supports grouping fields in a oneof clause. Only one of the fields in the group
+may be set at a given time. For example, given the proto:
+
+.. code-block:: proto
+
+    syntax = "proto3";
+
+    message Test {
+      oneof foo {
+        bool on = 1;
+        int32 count = 2;
+        string name = 3;
+      }
+    }
+
+You can use ``betterproto.which_one_of(message, group_name)`` to determine which of the
+fields was set. It returns a tuple of the field name and value, or a blank string and
+``None`` if unset. Again this is a little different than the official Google code
+generator:
+
+.. code-block:: python
+
+    # Old way (official Google protobuf package)
+    >>> message.WhichOneof("group")
+    "foo"
+
+    # New way (this project)
+    >>> betterproto.which_one_of(message, "group")
+    ("foo", "foo's value")
+
+
+Well-Known Google Types
+~~~~~~~~~~~~~~~~~~~~~~~
+
+Google provides several well-known message types like a timestamp, duration, and several
+wrappers used to provide optional zero value support. Each of these has a special JSON
+representation and is handled a little differently from normal messages. The Python
+mapping for these is as follows:
+
++-------------------------------+-----------------------------------------------+--------------------------+
+| ``Google Message``            | ``Python Type``                               | ``Default``              |
++===============================+===============================================+==========================+
+| ``google.protobuf.duration``  | :class:`datetime.timedelta`                   | ``0``                    |
++-------------------------------+-----------------------------------------------+--------------------------+
+| ``google.protobuf.timestamp`` | ``Timezone-aware`` :class:`datetime.datetime` | ``1970-01-01T00:00:00Z`` |
++-------------------------------+-----------------------------------------------+--------------------------+
+| ``google.protobuf.*Value``    | ``Optional[...]``/``None``                    | ``None``                 |
++-------------------------------+-----------------------------------------------+--------------------------+
+| ``google.protobuf.*``         | ``betterproto.lib.google.protobuf.*``         | ``None``                 |
++-------------------------------+-----------------------------------------------+--------------------------+
+
+
+For the wrapper types, the Python type corresponds to the wrapped type, e.g.
+``google.protobuf.BoolValue`` becomes ``Optional[bool]`` while
+``google.protobuf.Int32Value`` becomes ``Optional[int]``. All of the optional values
+default to None, so don't forget to check for that possible state.
+
+Given:
+
+.. code-block:: proto
+
+    syntax = "proto3";
+
+    import "google/protobuf/duration.proto";
+    import "google/protobuf/timestamp.proto";
+    import "google/protobuf/wrappers.proto";
+
+    message Test {
+      google.protobuf.BoolValue maybe = 1;
+      google.protobuf.Timestamp ts = 2;
+      google.protobuf.Duration duration = 3;
+    }
+
+You can use it as such:
+
+.. code-block:: python
+
+    >>> t = Test().from_dict({"maybe": True, "ts": "2019-01-01T12:00:00Z", "duration": "1.200s"})
+    >>> t
+    Test(maybe=True, ts=datetime.datetime(2019, 1, 1, 12, 0, tzinfo=datetime.timezone.utc), duration=datetime.timedelta(seconds=1, microseconds=200000))
+
+    >>> t.ts - t.duration
+    datetime.datetime(2019, 1, 1, 11, 59, 58, 800000, tzinfo=datetime.timezone.utc)
+
+    >>> t.ts.isoformat()
+    '2019-01-01T12:00:00+00:00'
+
+    >>> t.maybe = None
+    >>> t.to_dict()
+    {'ts': '2019-01-01T12:00:00Z', 'duration': '1.200s'}
+
+
+[1.2.5] to [2.0.0b1]
+--------------------
+
+Updated package structures
+~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Generated code now strictly follows the *package structure* of the ``.proto`` files.
+Consequently ``.proto`` files without a package will be combined in a single
+``__init__.py`` file. To avoid overwriting existing ``__init__.py`` files, its best
+to compile into a dedicated subdirectory.
+
+Upgrading:
+
+- Remove your previously compiled ``.py`` files.
+- Create a new *empty* directory, e.g. ``generated`` or ``lib/generated/proto`` etc.
+- Regenerate your python files into this directory
+- Update import statements, e.g. ``import ExampleMessage from generated``

docs/quick-start.rst

@@ -0,0 +1,192 @@
+Getting Started
+===============
+
+Installation
+++++++++++++
+
+Installation from PyPI is as simple as running:
+
+.. code-block:: sh
+
+    python3 -m pip install -U betterproto
+
+If you are using Windows, then the following should be used instead:
+
+.. code-block:: sh
+
+    py -3 -m pip install -U betterproto
+
+To include the protoc plugin, install betterproto[compiler] instead of betterproto,
+e.g.
+
+.. code-block:: sh
+
+    python3 -m pip install -U "betterproto[compiler]"
+
+Compiling proto files
++++++++++++++++++++++
+
+
+Given you installed the compiler and have a proto file, e.g ``example.proto``:
+
+.. code-block:: proto
+
+    syntax = "proto3";
+
+    package hello;
+
+    // Greeting represents a message you can tell a user.
+    message Greeting {
+      string message = 1;
+    }
+
+To compile the proto you would run the following:
+
+You can run the following to invoke protoc directly:
+
+.. code-block:: sh
+
+    mkdir hello
+    protoc -I . --python_betterproto_out=lib example.proto
+
+or run the following to invoke protoc via grpcio-tools:
+
+.. code-block:: sh
+
+    pip install grpcio-tools
+    python -m grpc_tools.protoc -I . --python_betterproto_out=lib example.proto
+
+
+This will generate ``lib/__init__.py`` which looks like:
+
+.. code-block:: python
+
+    # Generated by the protocol buffer compiler.  DO NOT EDIT!
+    # sources: example.proto
+    # plugin: python-betterproto
+    from dataclasses import dataclass
+
+    import betterproto
+
+
+    @dataclass
+    class Greeting(betterproto.Message):
+        """Greeting represents a message you can tell a user."""
+
+        message: str = betterproto.string_field(1)
+
+
+Then to use it:
+
+.. code-block:: python
+
+    >>> from lib import Greeting
+
+    >>> test = Greeting()
+    >>> test
+    Greeting(message='')
+
+    >>> test.message = "Hey!"
+    >>> test
+    Greeting(message="Hey!")
+
+    >>> bytes(test)
+    b'\n\x04Hey!'
+    >>> Greeting().parse(serialized)
+    Greeting(message="Hey!")
+
+
+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.
+It is enabled by default.
+
+
+Given a service definition similar to the one below:
+
+.. code-block:: proto
+
+    syntax = "proto3";
+
+    package echo;
+
+    message EchoRequest {
+      string value = 1;
+      // Number of extra times to echo
+      uint32 extra_times = 2;
+    }
+
+    message EchoResponse {
+      repeated string values = 1;
+    }
+
+    message EchoStreamResponse  {
+      string value = 1;
+    }
+
+    service Echo {
+      rpc Echo(EchoRequest) returns (EchoResponse);
+      rpc EchoStream(EchoRequest) returns (stream EchoStreamResponse);
+    }
+
+The generated client can be used like so:
+
+.. code-block:: python
+
+    import asyncio
+    from grpclib.client import Channel
+    import echo
+
+
+    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)
+        print(response)
+
+        async for response in service.echo_stream(value="hello", extra_times=1):
+            print(response)
+
+        # don't forget to close the channel when you're done!
+        channel.close()
+
+    asyncio.run(main())  # python 3.7 only
+
+    # outputs
+    EchoResponse(values=['hello', 'hello'])
+    EchoStreamResponse(value='hello')
+    EchoStreamResponse(value='hello')
+
+
+JSON
+++++
+Message objects include :meth:`betterproto.Message.to_json` and
+:meth:`betterproto.Message.from_json` methods for JSON (de)serialisation, and
+:meth:`betterproto.Message.to_dict`, :meth:`betterproto.Message.from_dict` for
+converting back and forth from JSON serializable dicts.
+
+For compatibility the default is to convert field names to
+:attr:`betterproto.Casing.CAMEL`. You can control this behavior by passing a
+different casing value, e.g:
+
+.. code-block:: python
+
+    @dataclass
+    class MyMessage(betterproto.Message):
+        a_long_field_name: str = betterproto.string_field(1)
+
+
+    >>> test = MyMessage(a_long_field_name="Hello World!")
+    >>> test.to_dict(betterproto.Casing.SNAKE)
+    {"a_long_field_name": "Hello World!"}
+    >>> test.to_dict(betterproto.Casing.CAMEL)
+    {"aLongFieldName": "Hello World!"}
+
+    >>> test.to_json(indent=2)
+    '{\n  "aLongFieldName": "Hello World!"\n}'
+
+    >>> test.from_dict({"aLongFieldName": "Goodbye World!"})
+    >>> test.a_long_field_name
+    "Goodbye World!"

pyproject.toml

@@ -1,34 +1,41 @@
 [tool.poetry]
 name = "betterproto"
-version = "1.2.5"
+version = "2.0.0b2"
 description = "A better Protobuf / gRPC generator & library"
 authors = ["Daniel G. Taylor <danielgtaylor@gmail.com>"]
 readme = "README.md"
 repository = "https://github.com/danielgtaylor/python-betterproto"
 keywords = ["protobuf", "gRPC"]
 license = "MIT"
-
-exclude = ["betterproto/tests"]
+packages = [
+    { include = "betterproto", from = "src" }
+]
 
 [tool.poetry.dependencies]
 python = "^3.6"
 backports-datetime-fromisoformat = { version = "^1.0.0", python = "<3.7" }
-black = { version = "^19.10b0", optional = true }
+black = { version = ">=19.3b0", optional = true }
 dataclasses = { version = "^0.7", python = ">=3.6, <3.7" }
-grpclib = "^0.3.1"
+grpclib = "^0.4.1"
 jinja2 = { version = "^2.11.2", optional = true }
 protobuf = { version = "^3.12.2", optional = true }
 
 [tool.poetry.dev-dependencies]
-black = "^19.10b0"
+black = "^20.8b1"
 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"
 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"
 
 [tool.poetry.scripts]
 protoc-gen-python_betterproto = "betterproto.plugin:main"
@@ -36,6 +43,20 @@ protoc-gen-python_betterproto = "betterproto.plugin:main"
 [tool.poetry.extras]
 compiler = ["black", "jinja2", "protobuf"]
 
+[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"}
+
+# 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.black]
 target-version = ['py36']
 
@@ -56,5 +77,5 @@ commands =
 """
 
 [build-system]
-requires = ["poetry>=0.12"]
-build-backend = "poetry.masonry.api"
+requires = ["poetry-core>=1.0.0,<2"]
+build-backend = "poetry.core.masonry.api"

src/betterproto/__init__.py

@@ -4,6 +4,7 @@ import inspect
 import json
 import struct
 import sys
+import typing
 from abc import ABC
 from base64 import b64decode, b64encode
 from datetime import datetime, timedelta, timezone
@@ -22,10 +23,10 @@ from typing import (
 )
 
 from ._types import T
-from .casing import camel_case, safe_snake_case, safe_snake_case, snake_case
+from .casing import camel_case, safe_snake_case, snake_case
 from .grpc.grpclib_client import ServiceStub
 
-if not (sys.version_info.major == 3 and sys.version_info.minor >= 7):
+if sys.version_info[:2] < (3, 7):
     # Apply backport of datetime.fromisoformat from 3.7
     from backports.datetime_fromisoformat import MonkeyPatch
 
@@ -109,7 +110,7 @@ WIRE_LEN_DELIM_TYPES = [TYPE_STRING, TYPE_BYTES, TYPE_MESSAGE, TYPE_MAP]
 
 
 # Protobuf datetimes start at the Unix Epoch in 1970 in UTC.
-def datetime_default_gen():
+def datetime_default_gen() -> datetime:
     return datetime(1970, 1, 1, tzinfo=timezone.utc)
 
 
@@ -119,15 +120,11 @@ DATETIME_ZERO = datetime_default_gen()
 class Casing(enum.Enum):
     """Casing constants for serialization."""
 
-    CAMEL = camel_case
-    SNAKE = snake_case
+    CAMEL = camel_case  #: A camelCase sterilization function.
+    SNAKE = snake_case  #: A snake_case sterilization function.
 
 
-class _PLACEHOLDER:
-    pass
-
-
-PLACEHOLDER: Any = _PLACEHOLDER()
+PLACEHOLDER: Any = object()
 
 
 @dataclasses.dataclass(frozen=True)
@@ -251,14 +248,28 @@ def map_field(
     )
 
 
-class Enum(int, enum.Enum):
-    """Protocol buffers enumeration base class. Acts like `enum.IntEnum`."""
+class Enum(enum.IntEnum):
+    """
+    The base class for protobuf enumerations, all generated enumerations will inherit
+    from this. Bases :class:`enum.IntEnum`.
+    """
 
     @classmethod
-    def from_string(cls, name: str) -> int:
-        """Return the value which corresponds to the string name."""
+    def from_string(cls, name: str) -> "Enum":
+        """Return the value which corresponds to the string name.
+
+        Parameters
+        -----------
+        name: :class:`str`
+            The name of the enum member to get
+
+        Raises
+        -------
+        :exc:`ValueError`
+            The member was not found in the Enum.
+        """
         try:
-            return cls.__members__[name]
+            return cls._member_map_[name]
         except KeyError as e:
             raise ValueError(f"Unknown value {name} for enum {cls.__name__}") from e
 
@@ -304,11 +315,7 @@ def _preprocess_single(proto_type: str, wraps: str, value: Any) -> bytes:
         return encode_varint(value)
     elif proto_type in [TYPE_SINT32, TYPE_SINT64]:
         # Handle zig-zag encoding.
-        if value >= 0:
-            value = value << 1
-        else:
-            value = (value << 1) ^ (~0)
-        return encode_varint(value)
+        return encode_varint(value << 1 if value >= 0 else (value << 1) ^ (~0))
     elif proto_type in FIXED_TYPES:
         return struct.pack(_pack_fmt(proto_type), value)
     elif proto_type == TYPE_STRING:
@@ -346,7 +353,7 @@ def _serialize_single(
     """Serializes a single field and value."""
     value = _preprocess_single(proto_type, wraps, value)
 
-    output = b""
+    output = bytearray()
     if proto_type in WIRE_VARINT_TYPES:
         key = encode_varint(field_number << 3)
         output += key + value
@@ -363,10 +370,10 @@ def _serialize_single(
     else:
         raise NotImplementedError(proto_type)
 
-    return output
+    return bytes(output)
 
 
-def decode_varint(buffer: bytes, pos: int, signed: bool = False) -> Tuple[int, int]:
+def decode_varint(buffer: bytes, pos: int) -> Tuple[int, int]:
     """
     Decode a single varint value from a byte buffer. Returns the value and the
     new position in the buffer.
@@ -378,7 +385,7 @@ def decode_varint(buffer: bytes, pos: int, signed: bool = False) -> Tuple[int, i
         result |= (b & 0x7F) << shift
         pos += 1
         if not (b & 0x80):
-            return (result, pos)
+            return result, pos
         shift += 7
         if shift >= 64:
             raise ValueError("Too many bytes when decoding varint.")
@@ -401,15 +408,15 @@ def parse_fields(value: bytes) -> Generator[ParsedField, None, None]:
         wire_type = num_wire & 0x7
 
         decoded: Any = None
-        if wire_type == 0:
+        if wire_type == WIRE_VARINT:
             decoded, i = decode_varint(value, i)
-        elif wire_type == 1:
+        elif wire_type == WIRE_FIXED_64:
             decoded, i = value[i : i + 8], i + 8
-        elif wire_type == 2:
+        elif wire_type == WIRE_LEN_DELIM:
             length, i = decode_varint(value, i)
             decoded = value[i : i + length]
             i += length
-        elif wire_type == 5:
+        elif wire_type == WIRE_FIXED_32:
             decoded, i = value[i : i + 4], i + 4
 
         yield ParsedField(
@@ -418,12 +425,6 @@ def parse_fields(value: bytes) -> Generator[ParsedField, None, None]:
 
 
 class ProtoClassMetadata:
-    oneof_group_by_field: Dict[str, str]
-    oneof_field_by_group: Dict[str, Set[dataclasses.Field]]
-    default_gen: Dict[str, Callable]
-    cls_by_field: Dict[str, Type]
-    field_name_by_number: Dict[int, str]
-    meta_by_field_name: Dict[str, FieldMetadata]
     __slots__ = (
         "oneof_group_by_field",
         "oneof_field_by_group",
@@ -431,8 +432,17 @@ class ProtoClassMetadata:
         "cls_by_field",
         "field_name_by_number",
         "meta_by_field_name",
+        "sorted_field_names",
     )
 
+    oneof_group_by_field: Dict[str, str]
+    oneof_field_by_group: Dict[str, Set[dataclasses.Field]]
+    field_name_by_number: Dict[int, str]
+    meta_by_field_name: Dict[str, FieldMetadata]
+    sorted_field_names: Tuple[str, ...]
+    default_gen: Dict[str, Callable[[], Any]]
+    cls_by_field: Dict[str, Type]
+
     def __init__(self, cls: Type["Message"]):
         by_field = {}
         by_group: Dict[str, Set] = {}
@@ -456,21 +466,22 @@ class ProtoClassMetadata:
         self.oneof_field_by_group = by_group
         self.field_name_by_number = by_field_number
         self.meta_by_field_name = by_field_name
-
+        self.sorted_field_names = tuple(
+            by_field_number[number] for number in sorted(by_field_number)
+        )
         self.default_gen = self._get_default_gen(cls, fields)
         self.cls_by_field = self._get_cls_by_field(cls, fields)
 
     @staticmethod
-    def _get_default_gen(cls, fields):
-        default_gen = {}
-
-        for field in fields:
-            default_gen[field.name] = cls._get_field_default_gen(field)
-
-        return default_gen
+    def _get_default_gen(
+        cls: Type["Message"], fields: List[dataclasses.Field]
+    ) -> Dict[str, Callable[[], Any]]:
+        return {field.name: cls._get_field_default_gen(field) for field in fields}
 
     @staticmethod
-    def _get_cls_by_field(cls, fields):
+    def _get_cls_by_field(
+        cls: Type["Message"], fields: List[dataclasses.Field]
+    ) -> Dict[str, Type]:
         field_cls = {}
 
         for field in fields:
@@ -479,7 +490,7 @@ class ProtoClassMetadata:
                 assert meta.map_types
                 kt = cls._cls_for(field, index=0)
                 vt = cls._cls_for(field, index=1)
-                Entry = dataclasses.make_dataclass(
+                field_cls[field.name] = dataclasses.make_dataclass(
                     "Entry",
                     [
                         ("key", kt, dataclass_field(1, meta.map_types[0])),
@@ -487,8 +498,7 @@ class ProtoClassMetadata:
                     ],
                     bases=(Message,),
                 )
-                field_cls[field.name] = Entry
-                field_cls[field.name + ".value"] = vt
+                field_cls[f"{field.name}.value"] = vt
             else:
                 field_cls[field.name] = cls._cls_for(field)
 
@@ -497,9 +507,19 @@ class ProtoClassMetadata:
 
 class Message(ABC):
     """
-    A protobuf message base class. Generated code will inherit from this and
-    register the message fields which get used by the serializers and parsers
-    to go between Python, binary and JSON protobuf message representations.
+    The base class for protobuf messages, all generated messages will inherit from
+    this. This class registers the message fields which are used by the serializers and
+    parsers to go between the Python, binary and JSON representations of the message.
+
+    .. container:: operations
+
+        .. describe:: bytes(x)
+
+            Calls :meth:`__bytes__`.
+
+        .. describe:: bool(x)
+
+            Calls :meth:`__bool__`.
     """
 
     _serialized_on_wire: bool
@@ -511,29 +531,69 @@ class Message(ABC):
         all_sentinel = True
 
         # Set current field of each group after `__init__` has already been run.
-        group_current: Dict[str, str] = {}
+        group_current: Dict[str, Optional[str]] = {}
         for field_name, meta in self._betterproto.meta_by_field_name.items():
 
             if meta.group:
                 group_current.setdefault(meta.group)
 
-            if getattr(self, field_name) != PLACEHOLDER:
-                # Skip anything not set to the sentinel value
+            if self.__raw_get(field_name) != PLACEHOLDER:
+                # Found a non-sentinel value
                 all_sentinel = False
 
                 if meta.group:
                     # This was set, so make it the selected value of the one-of.
                     group_current[meta.group] = field_name
 
-                continue
-
-            setattr(self, field_name, self._get_field_default(field_name))
-
         # Now that all the defaults are set, reset it!
         self.__dict__["_serialized_on_wire"] = not all_sentinel
         self.__dict__["_unknown_fields"] = b""
         self.__dict__["_group_current"] = group_current
 
+    def __raw_get(self, name: str) -> Any:
+        return super().__getattribute__(name)
+
+    def __eq__(self, other) -> bool:
+        if type(self) is not type(other):
+            return False
+
+        for field_name in self._betterproto.meta_by_field_name:
+            self_val = self.__raw_get(field_name)
+            other_val = other.__raw_get(field_name)
+            if self_val is PLACEHOLDER:
+                if other_val is PLACEHOLDER:
+                    continue
+                self_val = self._get_field_default(field_name)
+            elif other_val is PLACEHOLDER:
+                other_val = other._get_field_default(field_name)
+
+            if self_val != other_val:
+                return False
+
+        return True
+
+    def __repr__(self) -> str:
+        parts = [
+            f"{field_name}={value!r}"
+            for field_name in self._betterproto.sorted_field_names
+            for value in (self.__raw_get(field_name),)
+            if value is not PLACEHOLDER
+        ]
+        return f"{self.__class__.__name__}({', '.join(parts)})"
+
+    def __getattribute__(self, name: str) -> Any:
+        """
+        Lazily initialize default values to avoid infinite recursion for recursive
+        message types
+        """
+        value = super().__getattribute__(name)
+        if value is not PLACEHOLDER:
+            return value
+
+        value = self._get_field_default(name)
+        super().__setattr__(name, value)
+        return value
+
     def __setattr__(self, attr: str, value: Any) -> None:
         if attr != "_serialized_on_wire":
             # Track when a field has been set.
@@ -546,14 +606,20 @@ class Message(ABC):
                     if field.name == attr:
                         self._group_current[group] = field.name
                     else:
-                        super().__setattr__(
-                            field.name, self._get_field_default(field.name),
-                        )
+                        super().__setattr__(field.name, PLACEHOLDER)
 
         super().__setattr__(attr, value)
 
+    def __bool__(self) -> bool:
+        """True if the Message has any fields with non-default values."""
+        return any(
+            self.__raw_get(field_name)
+            not in (PLACEHOLDER, self._get_field_default(field_name))
+            for field_name in self._betterproto.meta_by_field_name
+        )
+
     @property
-    def _betterproto(self):
+    def _betterproto(self) -> ProtoClassMetadata:
         """
         Lazy initialize metadata for each protobuf class.
         It may be initialized multiple times in a multi-threaded environment,
@@ -567,9 +633,9 @@ class Message(ABC):
 
     def __bytes__(self) -> bytes:
         """
-        Get the binary encoded Protobuf representation of this instance.
+        Get the binary encoded Protobuf representation of this message instance.
         """
-        output = b""
+        output = bytearray()
         for field_name, meta in self._betterproto.meta_by_field_name.items():
             value = getattr(self, field_name)
 
@@ -581,18 +647,20 @@ class Message(ABC):
             # Being selected in a a group means this field is the one that is
             # currently set in a `oneof` group, so it must be serialized even
             # if the value is the default zero value.
-            selected_in_group = False
-            if meta.group and self._group_current[meta.group] == field_name:
-                selected_in_group = True
+            selected_in_group = (
+                meta.group and self._group_current[meta.group] == field_name
+            )
 
-            serialize_empty = False
-            if isinstance(value, Message) and value._serialized_on_wire:
-                # Empty messages can still be sent on the wire if they were
-                # set (or recieved empty).
-                serialize_empty = True
+            # Empty messages can still be sent on the wire if they were
+            # set (or received empty).
+            serialize_empty = isinstance(value, Message) and value._serialized_on_wire
+
+            include_default_value_for_oneof = self._include_default_value_for_oneof(
+                field_name=field_name, meta=meta
+            )
 
             if value == self._get_field_default(field_name) and not (
-                selected_in_group or serialize_empty
+                selected_in_group or serialize_empty or include_default_value_for_oneof
             ):
                 # Default (zero) values are not serialized. Two exceptions are
                 # if this is the selected oneof item or if we know we have to
@@ -605,7 +673,7 @@ class Message(ABC):
                     # Packed lists look like a length-delimited field. First,
                     # preprocess/encode each value into a buffer and then
                     # treat it like a field of raw bytes.
-                    buf = b""
+                    buf = bytearray()
                     for item in value:
                         buf += _preprocess_single(meta.proto_type, "", item)
                     output += _serialize_single(meta.number, TYPE_BYTES, buf)
@@ -621,6 +689,17 @@ class Message(ABC):
                     sv = _serialize_single(2, meta.map_types[1], v)
                     output += _serialize_single(meta.number, meta.proto_type, sk + sv)
             else:
+                # If we have an empty string and we're including the default value for
+                # a oneof, make sure we serialize it. This ensures that the byte string
+                # output isn't simply an empty string. This also ensures that round trip
+                # serialization will keep `which_one_of` calls consistent.
+                if (
+                    isinstance(value, str)
+                    and value == ""
+                    and include_default_value_for_oneof
+                ):
+                    serialize_empty = True
+
                 output += _serialize_single(
                     meta.number,
                     meta.proto_type,
@@ -629,26 +708,44 @@ class Message(ABC):
                     wraps=meta.wraps or "",
                 )
 
-        return output + self._unknown_fields
+        output += self._unknown_fields
+        return bytes(output)
 
     # For compatibility with other libraries
-    SerializeToString = __bytes__
+    def SerializeToString(self: T) -> bytes:
+        """
+        Get the binary encoded Protobuf representation of this message instance.
+
+        .. note::
+            This is a method for compatibility with other libraries,
+            you should really use ``bytes(x)``.
+
+        Returns
+        --------
+        :class:`bytes`
+            The binary encoded Protobuf representation of this message instance
+        """
+        return bytes(self)
 
     @classmethod
     def _type_hint(cls, field_name: str) -> Type:
-        module = inspect.getmodule(cls)
-        type_hints = get_type_hints(cls, vars(module))
-        return type_hints[field_name]
+        return cls._type_hints()[field_name]
+
+    @classmethod
+    def _type_hints(cls) -> Dict[str, Type]:
+        module = sys.modules[cls.__module__]
+        return get_type_hints(cls, vars(module))
 
     @classmethod
     def _cls_for(cls, field: dataclasses.Field, index: int = 0) -> Type:
         """Get the message class for a field from the type hints."""
         field_cls = cls._type_hint(field.name)
         if hasattr(field_cls, "__args__") and index >= 0:
-            field_cls = field_cls.__args__[index]
+            if field_cls.__args__ is not None:
+                field_cls = field_cls.__args__[index]
         return field_cls
 
-    def _get_field_default(self, field_name):
+    def _get_field_default(self, field_name: str) -> Any:
         return self._betterproto.default_gen[field_name]()
 
     @classmethod
@@ -662,7 +759,7 @@ class Message(ABC):
             elif t.__origin__ in (list, List):
                 # This is some kind of list (repeated) field.
                 return list
-            elif t.__origin__ == Union and t.__args__[1] == type(None):
+            elif t.__origin__ is Union and t.__args__[1] is type(None):
                 # This is an optional (wrapped) field. For setting the default we
                 # really don't care what kind of field it is.
                 return type(None)
@@ -671,7 +768,7 @@ class Message(ABC):
         elif issubclass(t, Enum):
             # Enums always default to zero.
             return int
-        elif t == datetime:
+        elif t is datetime:
             # Offsets are relative to 1970-01-01T00:00:00Z
             return datetime_default_gen
         else:
@@ -720,18 +817,38 @@ class Message(ABC):
 
         return value
 
+    def _include_default_value_for_oneof(
+        self, field_name: str, meta: FieldMetadata
+    ) -> bool:
+        return (
+            meta.group is not None and self._group_current.get(meta.group) == field_name
+        )
+
     def parse(self: T, data: bytes) -> T:
         """
         Parse the binary encoded Protobuf into this message instance. This
         returns the instance itself and is therefore assignable and chainable.
+
+        Parameters
+        -----------
+        data: :class:`bytes`
+            The data to parse the protobuf from.
+
+        Returns
+        --------
+        :class:`Message`
+            The initialized message.
         """
+        # Got some data over the wire
+        self._serialized_on_wire = True
+        proto_meta = self._betterproto
         for parsed in parse_fields(data):
-            field_name = self._betterproto.field_name_by_number.get(parsed.number)
+            field_name = proto_meta.field_name_by_number.get(parsed.number)
             if not field_name:
                 self._unknown_fields += parsed.raw
                 continue
 
-            meta = self._betterproto.meta_by_field_name[field_name]
+            meta = proto_meta.meta_by_field_name[field_name]
 
             value: Any
             if parsed.wire_type == WIRE_LEN_DELIM and meta.proto_type in PACKED_TYPES:
@@ -739,10 +856,10 @@ class Message(ABC):
                 pos = 0
                 value = []
                 while pos < len(parsed.value):
-                    if meta.proto_type in ["float", "fixed32", "sfixed32"]:
+                    if meta.proto_type in [TYPE_FLOAT, TYPE_FIXED32, TYPE_SFIXED32]:
                         decoded, pos = parsed.value[pos : pos + 4], pos + 4
                         wire_type = WIRE_FIXED_32
-                    elif meta.proto_type in ["double", "fixed64", "sfixed64"]:
+                    elif meta.proto_type in [TYPE_DOUBLE, TYPE_FIXED64, TYPE_SFIXED64]:
                         decoded, pos = parsed.value[pos : pos + 8], pos + 8
                         wire_type = WIRE_FIXED_64
                     else:
@@ -771,80 +888,149 @@ class Message(ABC):
     # For compatibility with other libraries.
     @classmethod
     def FromString(cls: Type[T], data: bytes) -> T:
+        """
+        Parse the binary encoded Protobuf into this message instance. This
+        returns the instance itself and is therefore assignable and chainable.
+
+        .. note::
+            This is a method for compatibility with other libraries,
+            you should really use :meth:`parse`.
+
+
+        Parameters
+        -----------
+        data: :class:`bytes`
+            The data to parse the protobuf from.
+
+        Returns
+        --------
+        :class:`Message`
+            The initialized message.
+        """
         return cls().parse(data)
 
     def to_dict(
         self, casing: Casing = Casing.CAMEL, include_default_values: bool = False
     ) -> Dict[str, Any]:
         """
-        Returns a dict representation of this message instance which can be
-        used to serialize to e.g. JSON. Defaults to camel casing for
-        compatibility but can be set to other modes.
+        Returns a JSON serializable dict representation of this object.
 
-        `include_default_values` can be set to `True` to include default
-        values of fields. E.g. an `int32` type field with `0` value will
-        not be in returned dict if `include_default_values` is set to
-        `False`.
+        Parameters
+        -----------
+        casing: :class:`Casing`
+            The casing to use for key values. Default is :attr:`Casing.CAMEL` for
+            compatibility purposes.
+        include_default_values: :class:`bool`
+            If ``True`` will include the default values of fields. Default is ``False``.
+            E.g. an ``int32`` field will be included with a value of ``0`` if this is
+            set to ``True``, otherwise this would be ignored.
+
+        Returns
+        --------
+        Dict[:class:`str`, Any]
+            The JSON serializable dict representation of this object.
         """
         output: Dict[str, Any] = {}
+        field_types = self._type_hints()
+        defaults = self._betterproto.default_gen
         for field_name, meta in self._betterproto.meta_by_field_name.items():
-            v = getattr(self, field_name)
+            field_is_repeated = defaults[field_name] is list
+            value = getattr(self, field_name)
             cased_name = casing(field_name).rstrip("_")  # type: ignore
-            if meta.proto_type == "message":
-                if isinstance(v, datetime):
-                    if v != DATETIME_ZERO or include_default_values:
-                        output[cased_name] = _Timestamp.timestamp_to_json(v)
-                elif isinstance(v, timedelta):
-                    if v != timedelta(0) or include_default_values:
-                        output[cased_name] = _Duration.delta_to_json(v)
+            if meta.proto_type == TYPE_MESSAGE:
+                if isinstance(value, datetime):
+                    if (
+                        value != DATETIME_ZERO
+                        or include_default_values
+                        or self._include_default_value_for_oneof(
+                            field_name=field_name, meta=meta
+                        )
+                    ):
+                        output[cased_name] = _Timestamp.timestamp_to_json(value)
+                elif isinstance(value, timedelta):
+                    if (
+                        value != timedelta(0)
+                        or include_default_values
+                        or self._include_default_value_for_oneof(
+                            field_name=field_name, meta=meta
+                        )
+                    ):
+                        output[cased_name] = _Duration.delta_to_json(value)
                 elif meta.wraps:
-                    if v is not None or include_default_values:
-                        output[cased_name] = v
-                elif isinstance(v, list):
+                    if value is not None or include_default_values:
+                        output[cased_name] = value
+                elif field_is_repeated:
                     # Convert each item.
-                    v = [i.to_dict(casing, include_default_values) for i in v]
-                    if v or include_default_values:
-                        output[cased_name] = v
-                else:
-                    if v._serialized_on_wire or include_default_values:
-                        output[cased_name] = v.to_dict(casing, include_default_values)
-            elif meta.proto_type == "map":
-                for k in v:
-                    if hasattr(v[k], "to_dict"):
-                        v[k] = v[k].to_dict(casing, include_default_values)
+                    value = [i.to_dict(casing, include_default_values) for i in value]
+                    if value or include_default_values:
+                        output[cased_name] = value
+                elif (
+                    value._serialized_on_wire
+                    or include_default_values
+                    or self._include_default_value_for_oneof(
+                        field_name=field_name, meta=meta
+                    )
+                ):
+                    output[cased_name] = value.to_dict(casing, include_default_values)
+            elif meta.proto_type == TYPE_MAP:
+                for k in value:
+                    if hasattr(value[k], "to_dict"):
+                        value[k] = value[k].to_dict(casing, include_default_values)
 
-                if v or include_default_values:
-                    output[cased_name] = v
-            elif v != self._get_field_default(field_name) or include_default_values:
+                if value or include_default_values:
+                    output[cased_name] = value
+            elif (
+                value != self._get_field_default(field_name)
+                or include_default_values
+                or self._include_default_value_for_oneof(
+                    field_name=field_name, meta=meta
+                )
+            ):
                 if meta.proto_type in INT_64_TYPES:
-                    if isinstance(v, list):
-                        output[cased_name] = [str(n) for n in v]
+                    if field_is_repeated:
+                        output[cased_name] = [str(n) for n in value]
                     else:
-                        output[cased_name] = str(v)
+                        output[cased_name] = str(value)
                 elif meta.proto_type == TYPE_BYTES:
-                    if isinstance(v, list):
-                        output[cased_name] = [b64encode(b).decode("utf8") for b in v]
+                    if field_is_repeated:
+                        output[cased_name] = [
+                            b64encode(b).decode("utf8") for b in value
+                        ]
                     else:
-                        output[cased_name] = b64encode(v).decode("utf8")
+                        output[cased_name] = b64encode(value).decode("utf8")
                 elif meta.proto_type == TYPE_ENUM:
-                    enum_values = list(
-                        self._betterproto.cls_by_field[field_name]
-                    )  # type: ignore
-                    if isinstance(v, list):
-                        output[cased_name] = [enum_values[e].name for e in v]
+                    if field_is_repeated:
+                        enum_class: Type[Enum] = field_types[field_name].__args__[0]
+                        if isinstance(value, typing.Iterable) and not isinstance(
+                            value, str
+                        ):
+                            output[cased_name] = [enum_class(el).name for el in value]
+                        else:
+                            # transparently upgrade single value to repeated
+                            output[cased_name] = [enum_class(value).name]
                     else:
-                        output[cased_name] = enum_values[v].name
+                        enum_class: Type[Enum] = field_types[field_name]  # noqa
+                        output[cased_name] = enum_class(value).name
                 else:
-                    output[cased_name] = v
+                    output[cased_name] = value
         return output
 
-    def from_dict(self: T, value: dict) -> T:
+    def from_dict(self: T, value: Dict[str, Any]) -> T:
         """
-        Parse the key/value pairs in `value` into this message instance. This
-        returns the instance itself and is therefore assignable and chainable.
+        Parse the key/value pairs into the current message instance. This returns the
+        instance itself and is therefore assignable and chainable.
+
+        Parameters
+        -----------
+        value: Dict[:class:`str`, Any]
+            The dictionary to parse from.
+
+        Returns
+        --------
+        :class:`Message`
+            The initialized message.
         """
         self._serialized_on_wire = True
-        fields_by_name = {f.name: f for f in dataclasses.fields(self)}
         for key in value:
             field_name = safe_snake_case(key)
             meta = self._betterproto.meta_by_field_name.get(field_name)
@@ -852,12 +1038,12 @@ class Message(ABC):
                 continue
 
             if value[key] is not None:
-                if meta.proto_type == "message":
+                if meta.proto_type == TYPE_MESSAGE:
                     v = getattr(self, field_name)
                     if isinstance(v, list):
                         cls = self._betterproto.cls_by_field[field_name]
-                        for i in range(len(value[key])):
-                            v.append(cls().from_dict(value[key][i]))
+                        for item in value[key]:
+                            v.append(cls().from_dict(item))
                     elif isinstance(v, datetime):
                         v = datetime.fromisoformat(value[key].replace("Z", "+00:00"))
                         setattr(self, field_name, v)
@@ -867,10 +1053,12 @@ class Message(ABC):
                     elif meta.wraps:
                         setattr(self, field_name, value[key])
                     else:
+                        # NOTE: `from_dict` mutates the underlying message, so no
+                        # assignment here is necessary.
                         v.from_dict(value[key])
                 elif meta.map_types and meta.map_types[1] == TYPE_MESSAGE:
                     v = getattr(self, field_name)
-                    cls = self._betterproto.cls_by_field[field_name + ".value"]
+                    cls = self._betterproto.cls_by_field[f"{field_name}.value"]
                     for k in value[key]:
                         v[k] = cls().from_dict(value[key][k])
                 else:
@@ -892,50 +1080,92 @@ class Message(ABC):
                         elif isinstance(v, str):
                             v = enum_cls.from_string(v)
 
-                    if v is not None:
-                        setattr(self, field_name, v)
+                if v is not None:
+                    setattr(self, field_name, v)
         return self
 
     def to_json(self, indent: Union[None, int, str] = None) -> str:
-        """Returns the encoded JSON representation of this message instance."""
+        """A helper function to parse the message instance into its JSON
+        representation.
+
+        This is equivalent to::
+
+            json.dumps(message.to_dict(), indent=indent)
+
+        Parameters
+        -----------
+        indent: Optional[Union[:class:`int`, :class:`str`]]
+            The indent to pass to :func:`json.dumps`.
+
+        Returns
+        --------
+        :class:`str`
+            The JSON representation of the message.
+        """
         return json.dumps(self.to_dict(), indent=indent)
 
     def from_json(self: T, value: Union[str, bytes]) -> T:
-        """
-        Parse the key/value pairs in `value` into this message instance. This
-        returns the instance itself and is therefore assignable and chainable.
+        """A helper function to return the message instance from its JSON
+        representation. This returns the instance itself and is therefore assignable
+        and chainable.
+
+        This is equivalent to::
+
+            return message.from_dict(json.loads(value))
+
+        Parameters
+        -----------
+        value: Union[:class:`str`, :class:`bytes`]
+            The value to pass to :func:`json.loads`.
+
+        Returns
+        --------
+        :class:`Message`
+            The initialized message.
         """
         return self.from_dict(json.loads(value))
 
 
 def serialized_on_wire(message: Message) -> bool:
     """
-    True if this message was or should be serialized on the wire. This can
-    be used to detect presence (e.g. optional wrapper message) and is used
-    internally during parsing/serialization.
+    If this message was or should be serialized on the wire. This can be used to detect
+    presence (e.g. optional wrapper message) and is used internally during
+    parsing/serialization.
+
+    Returns
+    --------
+    :class:`bool`
+        Whether this message was or should be serialized on the wire.
     """
     return message._serialized_on_wire
 
 
-def which_one_of(message: Message, group_name: str) -> Tuple[str, Any]:
-    """Return the name and value of a message's one-of field group."""
+def which_one_of(message: Message, group_name: str) -> Tuple[str, Optional[Any]]:
+    """
+    Return the name and value of a message's one-of field group.
+
+    Returns
+    --------
+    Tuple[:class:`str`, Any]
+        The field name and the value for that field.
+    """
     field_name = message._group_current.get(group_name)
     if not field_name:
-        return ("", None)
-    return (field_name, getattr(message, field_name))
+        return "", None
+    return field_name, getattr(message, field_name)
 
 
 # Circular import workaround: google.protobuf depends on base classes defined above.
-from .lib.google.protobuf import (
-    Duration,
-    Timestamp,
+from .lib.google.protobuf import (  # noqa
     BoolValue,
     BytesValue,
     DoubleValue,
+    Duration,
     FloatValue,
     Int32Value,
     Int64Value,
     StringValue,
+    Timestamp,
     UInt32Value,
     UInt64Value,
 )
@@ -950,8 +1180,8 @@ class _Duration(Duration):
         parts = str(delta.total_seconds()).split(".")
         if len(parts) > 1:
             while len(parts[1]) not in [3, 6, 9]:
-                parts[1] = parts[1] + "0"
-        return ".".join(parts) + "s"
+                parts[1] = f"{parts[1]}0"
+        return f"{'.'.join(parts)}s"
 
 
 class _Timestamp(Timestamp):
@@ -967,15 +1197,15 @@ class _Timestamp(Timestamp):
         if (nanos % 1e9) == 0:
             # If there are 0 fractional digits, the fractional
             # point '.' should be omitted when serializing.
-            return result + "Z"
+            return f"{result}Z"
         if (nanos % 1e6) == 0:
             # Serialize 3 fractional digits.
-            return result + ".%03dZ" % (nanos / 1e6)
+            return f"{result}.{int(nanos // 1e6) :03d}Z"
         if (nanos % 1e3) == 0:
             # Serialize 6 fractional digits.
-            return result + ".%06dZ" % (nanos / 1e3)
+            return f"{result}.{int(nanos // 1e3) :06d}Z"
         # Serialize 9 fractional digits.
-        return result + ".%09dZ" % nanos
+        return f"{result}.{nanos:09d}"
 
 
 class _WrappedMessage(Message):

src/betterproto/_types.py

@@ -1,8 +1,8 @@
 from typing import TYPE_CHECKING, TypeVar
 
 if TYPE_CHECKING:
+    from grpclib._typing import IProtoMessage
     from . import Message
-    from grpclib._protocols import IProtoMessage
 
 # Bound type variable to allow methods to return `self` of subclasses
 T = TypeVar("T", bound="Message")

src/betterproto/casing.py

@@ -1,3 +1,4 @@
+import keyword
 import re
 
 # Word delimiters and symbols that will not be preserved when re-casing.
@@ -16,51 +17,28 @@ WORD_UPPER = "[A-Z]+(?![a-z])[0-9]*"
 def safe_snake_case(value: str) -> str:
     """Snake case a value taking into account Python keywords."""
     value = snake_case(value)
-    if value in [
-        "and",
-        "as",
-        "assert",
-        "break",
-        "class",
-        "continue",
-        "def",
-        "del",
-        "elif",
-        "else",
-        "except",
-        "finally",
-        "for",
-        "from",
-        "global",
-        "if",
-        "import",
-        "in",
-        "is",
-        "lambda",
-        "nonlocal",
-        "not",
-        "or",
-        "pass",
-        "raise",
-        "return",
-        "try",
-        "while",
-        "with",
-        "yield",
-    ]:
-        # https://www.python.org/dev/peps/pep-0008/#descriptive-naming-styles
-        value += "_"
+    value = sanitize_name(value)
     return value
 
 
-def snake_case(value: str, strict: bool = True):
+def snake_case(value: str, strict: bool = True) -> str:
     """
     Join words with an underscore into lowercase and remove symbols.
-    @param value: value to convert
-    @param strict: force single underscores
+
+    Parameters
+    -----------
+    value: :class:`str`
+        The value to convert.
+    strict: :class:`bool`
+        Whether or not to force single underscores.
+
+    Returns
+    --------
+    :class:`str`
+        The value in snake_case.
     """
 
-    def substitute_word(symbols, word, is_start):
+    def substitute_word(symbols: str, word: str, is_start: bool) -> str:
         if not word:
             return ""
         if strict:
@@ -84,11 +62,21 @@ def snake_case(value: str, strict: bool = True):
     return snake
 
 
-def pascal_case(value: str, strict: bool = True):
+def pascal_case(value: str, strict: bool = True) -> str:
     """
     Capitalize each word and remove symbols.
-    @param value: value to convert
-    @param strict: output only alphanumeric characters
+
+    Parameters
+    -----------
+    value: :class:`str`
+        The value to convert.
+    strict: :class:`bool`
+        Whether or not to output only alphanumeric characters.
+
+    Returns
+    --------
+    :class:`str`
+        The value in PascalCase.
     """
 
     def substitute_word(symbols, word):
@@ -109,12 +97,42 @@ def pascal_case(value: str, strict: bool = True):
     )
 
 
-def camel_case(value: str, strict: bool = True):
+def camel_case(value: str, strict: bool = True) -> str:
     """
     Capitalize all words except first and remove symbols.
+
+    Parameters
+    -----------
+    value: :class:`str`
+        The value to convert.
+    strict: :class:`bool`
+        Whether or not to output only alphanumeric characters.
+
+    Returns
+    --------
+    :class:`str`
+        The value in camelCase.
     """
     return lowercase_first(pascal_case(value, strict=strict))
 
 
-def lowercase_first(value: str):
+def lowercase_first(value: str) -> str:
+    """
+    Lower cases the first character of the value.
+
+    Parameters
+    ----------
+    value: :class:`str`
+        The value to lower case.
+
+    Returns
+    -------
+    :class:`str`
+        The lower cased string.
+    """
     return value[0:1].lower() + value[1:]
+
+
+def sanitize_name(value: str) -> str:
+    # https://www.python.org/dev/peps/pep-0008/#descriptive-naming-styles
+    return f"{value}_" if keyword.iskeyword(value) else value

src/betterproto/compile/importing.py

@@ -1,10 +1,10 @@
 import os
 import re
-from typing import Dict, List, Set, Type
+from typing import Dict, List, Set, Tuple, Type
 
-from betterproto import safe_snake_case
-from betterproto.compile.naming import pythonize_class_name
-from betterproto.lib.google import protobuf as google_protobuf
+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,
@@ -19,7 +19,7 @@ WRAPPER_TYPES: Dict[str, Type] = {
 }
 
 
-def parse_source_type_name(field_type_name):
+def parse_source_type_name(field_type_name: str) -> Tuple[str, str]:
     """
     Split full source type name into package and type name.
     E.g. 'root.package.Message' -> ('root.package', 'Message')
@@ -36,7 +36,7 @@ def parse_source_type_name(field_type_name):
 
 
 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
@@ -50,7 +50,7 @@ def get_type_reference(
         if source_type == ".google.protobuf.Duration":
             return "timedelta"
 
-        if source_type == ".google.protobuf.Timestamp":
+        elif source_type == ".google.protobuf.Timestamp":
             return "datetime"
 
     source_package, source_type = parse_source_type_name(source_type)
@@ -79,14 +79,14 @@ def get_type_reference(
     return reference_cousin(current_package, imports, py_package, py_type)
 
 
-def reference_absolute(imports, py_package, py_type):
+def reference_absolute(imports: Set[str], py_package: List[str], py_type: str) -> str:
     """
     Returns a reference to a python type located in the root, i.e. sys.path.
     """
     string_import = ".".join(py_package)
     string_alias = safe_snake_case(string_import)
     imports.add(f"import {string_import} as {string_alias}")
-    return f"{string_alias}.{py_type}"
+    return f'"{string_alias}.{py_type}"'
 
 
 def reference_sibling(py_type: str) -> str:
@@ -109,10 +109,10 @@ def reference_descendent(
     if string_from:
         string_alias = "_".join(importing_descendent)
         imports.add(f"from .{string_from} import {string_import} as {string_alias}")
-        return f"{string_alias}.{py_type}"
+        return f'"{string_alias}.{py_type}"'
     else:
         imports.add(f"from . import {string_import}")
-        return f"{string_import}.{py_type}"
+        return f'"{string_import}.{py_type}"'
 
 
 def reference_ancestor(
@@ -130,11 +130,11 @@ def reference_ancestor(
         string_alias = f"_{'_' * distance_up}{string_import}__"
         string_from = f"..{'.' * distance_up}"
         imports.add(f"from {string_from} import {string_import} as {string_alias}")
-        return f"{string_alias}.{py_type}"
+        return f'"{string_alias}.{py_type}"'
     else:
         string_alias = f"{'_' * distance_up}{py_type}__"
         imports.add(f"from .{'.' * distance_up} import {py_type} as {string_alias}")
-        return string_alias
+        return f'"{string_alias}"'
 
 
 def reference_cousin(
@@ -157,4 +157,4 @@ def reference_cousin(
         + "__"
     )
     imports.add(f"from {string_from} import {string_import} as {string_alias}")
-    return f"{string_alias}.{py_type}"
+    return f'"{string_alias}.{py_type}"'

src/betterproto/compile/naming.py

@@ -1,13 +1,13 @@
 from betterproto import casing
 
 
-def pythonize_class_name(name):
+def pythonize_class_name(name: str) -> str:
     return casing.pascal_case(name)
 
 
-def pythonize_field_name(name: str):
+def pythonize_field_name(name: str) -> str:
     return casing.safe_snake_case(name)
 
 
-def pythonize_method_name(name: str):
+def pythonize_method_name(name: str) -> str:
     return casing.safe_snake_case(name)

src/betterproto/grpc/grpclib_client.py

@@ -1,8 +1,7 @@
-from abc import ABC
 import asyncio
-import grpclib.const
+from abc import ABC
 from typing import (
-    Any,
+    TYPE_CHECKING,
     AsyncIterable,
     AsyncIterator,
     Collection,
@@ -10,21 +9,23 @@ from typing import (
     Mapping,
     Optional,
     Tuple,
-    TYPE_CHECKING,
     Type,
     Union,
 )
+
+import grpclib.const
+
 from .._types import ST, T
 
 if TYPE_CHECKING:
-    from grpclib._protocols import IProtoMessage
-    from grpclib.client import Channel, Stream
+    from grpclib.client import Channel
     from grpclib.metadata import Deadline
 
 
 _Value = Union[str, bytes]
 _MetadataLike = Union[Mapping[str, _Value], Collection[Tuple[str, _Value]]]
-_MessageSource = Union[Iterable["IProtoMessage"], AsyncIterable["IProtoMessage"]]
+_MessageLike = Union[T, ST]
+_MessageSource = Union[Iterable[ST], AsyncIterable[ST]]
 
 
 class ServiceStub(ABC):
@@ -60,7 +61,7 @@ class ServiceStub(ABC):
     async def _unary_unary(
         self,
         route: str,
-        request: "IProtoMessage",
+        request: _MessageLike,
         response_type: Type[T],
         *,
         timeout: Optional[float] = None,
@@ -77,13 +78,13 @@ class ServiceStub(ABC):
         ) as stream:
             await stream.send_message(request, end=True)
             response = await stream.recv_message()
-            assert response is not None
-            return response
+        assert response is not None
+        return response
 
     async def _unary_stream(
         self,
         route: str,
-        request: "IProtoMessage",
+        request: _MessageLike,
         response_type: Type[T],
         *,
         timeout: Optional[float] = None,
@@ -123,8 +124,8 @@ class ServiceStub(ABC):
         ) as stream:
             await self._send_messages(stream, request_iterator)
             response = await stream.recv_message()
-            assert response is not None
-            return response
+        assert response is not None
+        return response
 
     async def _stream_stream(
         self,

src/betterproto/grpc/util/async_channel.py

@@ -1,12 +1,5 @@
 import asyncio
-from typing import (
-    AsyncIterable,
-    AsyncIterator,
-    Iterable,
-    Optional,
-    TypeVar,
-    Union,
-)
+from typing import AsyncIterable, AsyncIterator, Iterable, Optional, TypeVar, Union
 
 T = TypeVar("T")
 
@@ -16,57 +9,53 @@ class ChannelClosed(Exception):
     An exception raised on an attempt to send through a closed channel
     """
 
-    pass
-
 
 class ChannelDone(Exception):
     """
-    An exception raised on an attempt to send recieve from a channel that is both closed
+    An exception raised on an attempt to send receive from a channel that is both closed
     and empty.
     """
 
-    pass
-
 
 class AsyncChannel(AsyncIterable[T]):
     """
     A buffered async channel for sending items between coroutines with FIFO ordering.
 
-    This makes decoupled bidirection steaming gRPC requests easy if used like:
+    This makes decoupled bidirectional steaming gRPC requests easy if used like:
 
     .. code-block:: python
         client = GeneratedStub(grpclib_chan)
-        request_chan = await AsyncChannel()
+        request_channel = await AsyncChannel()
         # We can start be sending all the requests we already have
-        await request_chan.send_from([ReqestObject(...), ReqestObject(...)])
-        async for response in client.rpc_call(request_chan):
+        await request_channel.send_from([RequestObject(...), RequestObject(...)])
+        async for response in client.rpc_call(request_channel):
             # The response iterator will remain active until the connection is closed
             ...
             # More items can be sent at any time
-            await request_chan.send(ReqestObject(...))
+            await request_channel.send(RequestObject(...))
             ...
             # The channel must be closed to complete the gRPC connection
-            request_chan.close()
+            request_channel.close()
 
     Items can be sent through the channel by either:
     - providing an iterable to the send_from method
     - passing them to the send method one at a time
 
-    Items can be recieved from the channel by either:
+    Items can be received from the channel by either:
     - iterating over the channel with a for loop to get all items
-    - calling the recieve method to get one item at a time
+    - calling the receive method to get one item at a time
 
-    If the channel is empty then recievers will wait until either an item appears or the
+    If the channel is empty then receivers will wait until either an item appears or the
     channel is closed.
 
     Once the channel is closed then subsequent attempt to send through the channel will
     fail with a ChannelClosed exception.
 
-    When th channel is closed and empty then it is done, and further attempts to recieve
+    When th channel is closed and empty then it is done, and further attempts to receive
     from it will fail with a ChannelDone exception
 
-    If multiple coroutines recieve from the channel concurrently, each item sent will be
-    recieved by only one of the recievers.
+    If multiple coroutines receive from the channel concurrently, each item sent will be
+    received by only one of the receivers.
 
     :param source:
         An optional iterable will items that should be sent through the channel
@@ -74,18 +63,16 @@ class AsyncChannel(AsyncIterable[T]):
     :param buffer_limit:
         Limit the number of items that can be buffered in the channel, A value less than
         1 implies no limit. If the channel is full then attempts to send more items will
-        result in the sender waiting until an item is recieved from the channel.
+        result in the sender waiting until an item is received from the channel.
     :param close:
         If set to True then the channel will automatically close after exhausting source
         or immediately if no source is provided.
     """
 
-    def __init__(
-        self, *, buffer_limit: int = 0, close: bool = False,
-    ):
+    def __init__(self, *, buffer_limit: int = 0, close: bool = False):
         self._queue: asyncio.Queue[Union[T, object]] = asyncio.Queue(buffer_limit)
         self._closed = False
-        self._waiting_recievers: int = 0
+        self._waiting_receivers: int = 0
         # Track whether flush has been invoked so it can only happen once
         self._flushed = False
 
@@ -95,14 +82,14 @@ class AsyncChannel(AsyncIterable[T]):
     async def __anext__(self) -> T:
         if self.done():
             raise StopAsyncIteration
-        self._waiting_recievers += 1
+        self._waiting_receivers += 1
         try:
             result = await self._queue.get()
             if result is self.__flush:
                 raise StopAsyncIteration
             return result
         finally:
-            self._waiting_recievers -= 1
+            self._waiting_receivers -= 1
             self._queue.task_done()
 
     def closed(self) -> bool:
@@ -116,12 +103,12 @@ class AsyncChannel(AsyncIterable[T]):
         Check if this channel is done.
 
         :return: True if this channel is closed and and has been drained of items in
-        which case any further attempts to recieve an item from this channel will raise
+        which case any further attempts to receive an item from this channel will raise
         a ChannelDone exception.
         """
         # After close the channel is not yet done until there is at least one waiting
-        # reciever per enqueued item.
-        return self._closed and self._queue.qsize() <= self._waiting_recievers
+        # receiver per enqueued item.
+        return self._closed and self._queue.qsize() <= self._waiting_receivers
 
     async def send_from(
         self, source: Union[Iterable[T], AsyncIterable[T]], close: bool = False
@@ -158,22 +145,22 @@ class AsyncChannel(AsyncIterable[T]):
         await self._queue.put(item)
         return self
 
-    async def recieve(self) -> Optional[T]:
+    async def receive(self) -> Optional[T]:
         """
         Returns the next item from this channel when it becomes available,
         or None if the channel is closed before another item is sent.
         :return: An item from the channel
         """
         if self.done():
-            raise ChannelDone("Cannot recieve from a closed channel")
-        self._waiting_recievers += 1
+            raise ChannelDone("Cannot receive from a closed channel")
+        self._waiting_receivers += 1
         try:
             result = await self._queue.get()
             if result is self.__flush:
                 return None
             return result
         finally:
-            self._waiting_recievers -= 1
+            self._waiting_receivers -= 1
             self._queue.task_done()
 
     def close(self):
@@ -190,8 +177,8 @@ class AsyncChannel(AsyncIterable[T]):
         """
         if not self._flushed:
             self._flushed = True
-            deadlocked_recievers = max(0, self._waiting_recievers - self._queue.qsize())
-            for _ in range(deadlocked_recievers):
+            deadlocked_receivers = max(0, self._waiting_receivers - self._queue.qsize())
+            for _ in range(deadlocked_receivers):
                 await self._queue.put(self.__flush)
 
     # A special signal object for flushing the queue when the channel is closed

src/betterproto/plugin/__init__.py

@@ -0,0 +1 @@
+from .main import main

src/betterproto/plugin/__main__.py

@@ -0,0 +1,4 @@
+from .main import main
+
+
+main()

src/betterproto/plugin/compiler.py

@@ -0,0 +1,37 @@
+import os.path
+
+try:
+    # betterproto[compiler] specific dependencies
+    import black
+    import jinja2
+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 .models import OutputTemplate
+
+
+def outputfile_compiler(output_file: OutputTemplate) -> str:
+
+    templates_folder = os.path.abspath(
+        os.path.join(os.path.dirname(__file__), "..", "templates")
+    )
+
+    env = jinja2.Environment(
+        trim_blocks=True,
+        lstrip_blocks=True,
+        loader=jinja2.FileSystemLoader(templates_folder),
+    )
+    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}),
+    )

src/betterproto/plugin/main.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python
+
+import os
+import sys
+
+from google.protobuf.compiler import plugin_pb2 as plugin
+
+from betterproto.plugin.parser import generate_code
+
+
+def main() -> None:
+    """The plugin's main entry point."""
+    # Read request message from stdin
+    data = sys.stdin.buffer.read()
+
+    # Parse request
+    request = plugin.CodeGeneratorRequest()
+    request.ParseFromString(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)
+
+    # Serialise response message
+    output = response.SerializeToString()
+
+    # Write to stdout
+    sys.stdout.buffer.write(output)
+
+
+def dump_request(dump_file: str, request: plugin.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.
+    Then run plugin.py from your IDE in debugging mode, and redirect stdin to the file.
+    """
+    with open(str(dump_file), "wb") as fh:
+        sys.stderr.write(f"\033[31mWriting input from protoc to: {dump_file}\033[0m\n")
+        fh.write(request.SerializeToString())
+
+
+if __name__ == "__main__":
+    main()

src/betterproto/plugin/models.py

@@ -0,0 +1,706 @@
+"""Plugin model dataclasses.
+
+These classes are meant to be an intermediate representation
+of protobuf objects. They are used to organize the data collected during parsing.
+
+The general intention is to create a doubly-linked tree-like structure
+with the following types of references:
+- Downwards references: from message -> fields, from output package -> messages
+or from service -> service methods
+- Upwards references: from field -> message, message -> package.
+- Input/output message references: from a service method to it's corresponding
+input/output messages, which may even be in another package.
+
+There are convenience methods to allow climbing up and down this tree, for
+example to retrieve the list of all messages that are in the same package as
+the current message.
+
+Most of these classes take as inputs:
+- proto_obj: A reference to it's corresponding protobuf object as
+presented by the protoc plugin.
+- parent: a reference to the parent object in the tree.
+
+With this information, the class is able to expose attributes,
+such as a pythonized name, that will be calculated from proto_obj.
+
+The instantiation should also attach a reference to the new object
+into the corresponding place within it's parent object. For example,
+instantiating field `A` with parent message `B` should add a
+reference to `A` to `B`'s `fields` attribute.
+"""
+
+import re
+import textwrap
+from dataclasses import dataclass, field
+from typing import Dict, Iterator, List, Optional, Set, Text, Type, Union
+
+import betterproto
+
+from ..casing import sanitize_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
+PLACEHOLDER = object()
+
+# Organize proto types into categories
+PROTO_FLOAT_TYPES = (
+    FieldDescriptorProto.TYPE_DOUBLE,  # 1
+    FieldDescriptorProto.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
+)
+PROTO_BOOL_TYPES = (FieldDescriptorProto.TYPE_BOOL,)  # 8
+PROTO_STR_TYPES = (FieldDescriptorProto.TYPE_STRING,)  # 9
+PROTO_BYTES_TYPES = (FieldDescriptorProto.TYPE_BYTES,)  # 12
+PROTO_MESSAGE_TYPES = (
+    FieldDescriptorProto.TYPE_MESSAGE,  # 11
+    FieldDescriptorProto.TYPE_ENUM,  # 14
+)
+PROTO_MAP_TYPES = (FieldDescriptorProto.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
+)
+
+
+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:
+            lines = textwrap.wrap(
+                sci.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)
+            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}"""'
+
+    return ""
+
+
+class ProtoContentBase:
+    """Methods common to MessageCompiler, ServiceCompiler and ServiceMethodCompiler."""
+
+    path: List[int]
+    comment_indent: int = 4
+    parent: Union["betterproto.Message", "OutputTemplate"]
+
+    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():
+            if field_val is PLACEHOLDER:
+                raise ValueError(f"`{field_name}` is a required field.")
+
+    @property
+    def output_file(self) -> "OutputTemplate":
+        current = self
+        while not isinstance(current, OutputTemplate):
+            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
+        while not isinstance(current, OutputTemplate):
+            current = current.parent
+        return current.parent_request
+
+    @property
+    def comment(self) -> str:
+        """Crawl the proto source code and retrieve comments
+        for this object.
+        """
+        return get_comment(
+            proto_file=self.proto_file, path=self.path, indent=self.comment_indent
+        )
+
+
+@dataclass
+class PluginRequestCompiler:
+
+    plugin_request_obj: plugin.CodeGeneratorRequest
+    output_packages: Dict[str, "OutputTemplate"] = field(default_factory=dict)
+
+    @property
+    def all_messages(self) -> List["MessageCompiler"]:
+        """All of the messages in this request.
+
+        Returns
+        -------
+        List[MessageCompiler]
+            List of all of the messages in this request.
+        """
+        return [
+            msg for output in self.output_packages.values() for msg in output.messages
+        ]
+
+
+@dataclass
+class OutputTemplate:
+    """Representation of an output .py file.
+
+    Each output file corresponds to a .proto input file,
+    but may need references to other .proto files to be
+    built.
+    """
+
+    parent_request: PluginRequestCompiler
+    package_proto_obj: FileDescriptorProto
+    input_files: List[str] = field(default_factory=list)
+    imports: Set[str] = field(default_factory=set)
+    datetime_imports: Set[str] = field(default_factory=set)
+    typing_imports: Set[str] = field(default_factory=set)
+    messages: List["MessageCompiler"] = field(default_factory=list)
+    enums: List["EnumDefinitionCompiler"] = field(default_factory=list)
+    services: List["ServiceCompiler"] = field(default_factory=list)
+
+    @property
+    def package(self) -> str:
+        """Name of input package.
+
+        Returns
+        -------
+        str
+            Name of input package.
+        """
+        return self.package_proto_obj.package
+
+    @property
+    def input_filenames(self) -> List[str]:
+        """Names of the input files used to build this output.
+
+        Returns
+        -------
+        List[str]
+            Names of the input files used to build this output.
+        """
+        return [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")
+        return imports
+
+
+@dataclass
+class MessageCompiler(ProtoContentBase):
+    """Representation of a protobuf message."""
+
+    parent: Union["MessageCompiler", OutputTemplate] = PLACEHOLDER
+    proto_obj: DescriptorProto = PLACEHOLDER
+    path: List[int] = PLACEHOLDER
+    fields: List[Union["FieldCompiler", "MessageCompiler"]] = field(
+        default_factory=list
+    )
+    deprecated: bool = field(default=False, init=False)
+
+    def __post_init__(self) -> None:
+        # Add message to output file
+        if isinstance(self.parent, OutputTemplate):
+            if isinstance(self, EnumDefinitionCompiler):
+                self.output_file.enums.append(self)
+            else:
+                self.output_file.messages.append(self)
+        self.deprecated = self.proto_obj.options.deprecated
+        super().__post_init__()
+
+    @property
+    def proto_name(self) -> str:
+        return self.proto_obj.name
+
+    @property
+    def py_name(self) -> str:
+        return pythonize_class_name(self.proto_name)
+
+    @property
+    def annotation(self) -> str:
+        if self.repeated:
+            return f"List[{self.py_name}]"
+        return self.py_name
+
+    @property
+    def deprecated_fields(self) -> Iterator[str]:
+        for f in self.fields:
+            if f.deprecated:
+                yield f.py_name
+
+
+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:
+        # 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"
+        if message_type == map_entry:
+            for nested in parent_message.nested_type:  # parent message
+                if (
+                    nested.name.replace("_", "").lower() == map_entry
+                    and nested.options.map_entry
+                ):
+                    return True
+    return False
+
+
+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")
+
+
+@dataclass
+class FieldCompiler(MessageCompiler):
+    parent: MessageCompiler = PLACEHOLDER
+    proto_obj: FieldDescriptorProto = PLACEHOLDER
+
+    def __post_init__(self) -> None:
+        # 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")
+        super().__post_init__()  # call FieldCompiler-> MessageCompiler __post_init__
+
+    def get_field_string(self, indent: int = 4) -> str:
+        """Construct string representation of this field as a field."""
+        name = f"{self.py_name}"
+        annotations = f": {self.annotation}"
+        field_args = ", ".join(
+            ([""] + self.betterproto_field_args) if self.betterproto_field_args else []
+        )
+        betterproto_field_type = (
+            f"betterproto.{self.field_type}_field({self.proto_obj.number}{field_args})"
+        )
+        return f"{name}{annotations} = {betterproto_field_type}"
+
+    @property
+    def betterproto_field_args(self) -> List[str]:
+        args = []
+        if self.field_wraps:
+            args.append(f"wraps={self.field_wraps}")
+        return args
+
+    @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
+        )
+        if match_wrapper:
+            wrapped_type = "TYPE_" + match_wrapper.group(1).upper()
+            if hasattr(betterproto, wrapped_type):
+                return f"betterproto.{wrapped_type}"
+        return None
+
+    @property
+    def repeated(self) -> bool:
+        return (
+            self.proto_obj.label == FieldDescriptorProto.LABEL_REPEATED
+            and not is_map(self.proto_obj, self.parent)
+        )
+
+    @property
+    def mutable(self) -> bool:
+        """True if the field is a mutable type, otherwise False."""
+        return self.annotation.startswith(("List[", "Dict["))
+
+    @property
+    def field_type(self) -> str:
+        """String representation of proto field type."""
+        return (
+            self.proto_obj.Type.Name(self.proto_obj.type).lower().replace("type_", "")
+        )
+
+    @property
+    def default_value_string(self) -> Union[Text, None, float, int]:
+        """Python representation of the default proto value."""
+        if self.repeated:
+            return "[]"
+        if self.py_type == "int":
+            return "0"
+        if self.py_type == "float":
+            return "0.0"
+        elif self.py_type == "bool":
+            return "False"
+        elif self.py_type == "str":
+            return '""'
+        elif self.py_type == "bytes":
+            return 'b""'
+        else:
+            # Message type
+            return "None"
+
+    @property
+    def packed(self) -> bool:
+        """True if the wire representation is a packed format."""
+        return self.repeated and self.proto_obj.type in PROTO_PACKED_TYPES
+
+    @property
+    def py_name(self) -> str:
+        """Pythonized name."""
+        return pythonize_field_name(self.proto_name)
+
+    @property
+    def proto_name(self) -> str:
+        """Original protobuf name."""
+        return self.proto_obj.name
+
+    @property
+    def py_type(self) -> str:
+        """String representation of Python type."""
+        if self.proto_obj.type in PROTO_FLOAT_TYPES:
+            return "float"
+        elif self.proto_obj.type in PROTO_INT_TYPES:
+            return "int"
+        elif self.proto_obj.type in PROTO_BOOL_TYPES:
+            return "bool"
+        elif self.proto_obj.type in PROTO_STR_TYPES:
+            return "str"
+        elif self.proto_obj.type in PROTO_BYTES_TYPES:
+            return "bytes"
+        elif self.proto_obj.type in PROTO_MESSAGE_TYPES:
+            # Type referencing another defined Message or a named enum
+            return get_type_reference(
+                package=self.output_file.package,
+                imports=self.output_file.imports,
+                source_type=self.proto_obj.type_name,
+            )
+        else:
+            raise NotImplementedError(f"Unknown type {field.type}")
+
+    @property
+    def annotation(self) -> str:
+        if self.repeated:
+            return f"List[{self.py_type}]"
+        return self.py_type
+
+
+@dataclass
+class OneOfFieldCompiler(FieldCompiler):
+    @property
+    def betterproto_field_args(self) -> List[str]:
+        args = super().betterproto_field_args
+        group = self.parent.proto_obj.oneof_decl[self.proto_obj.oneof_index].name
+        args.append(f'group="{group}"')
+        return args
+
+
+@dataclass
+class MapEntryCompiler(FieldCompiler):
+    py_k_type: Type = PLACEHOLDER
+    py_v_type: Type = PLACEHOLDER
+    proto_k_type: str = PLACEHOLDER
+    proto_v_type: str = PLACEHOLDER
+
+    def __post_init__(self) -> None:
+        """Explore nested types and set k_type and v_type if unset."""
+        map_entry = f"{self.proto_obj.name.replace('_', '').lower()}entry"
+        for nested in self.parent.proto_obj.nested_type:
+            if (
+                nested.name.replace("_", "").lower() == map_entry
+                and nested.options.map_entry
+            ):
+                # Get Python types
+                self.py_k_type = FieldCompiler(
+                    parent=self, proto_obj=nested.field[0]  # key
+                ).py_type
+                self.py_v_type = FieldCompiler(
+                    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)
+        super().__post_init__()  # call FieldCompiler-> MessageCompiler __post_init__
+
+    @property
+    def betterproto_field_args(self) -> List[str]:
+        return [f"betterproto.{self.proto_k_type}", f"betterproto.{self.proto_v_type}"]
+
+    @property
+    def field_type(self) -> str:
+        return "map"
+
+    @property
+    def annotation(self) -> str:
+        return f"Dict[{self.py_k_type}, {self.py_v_type}]"
+
+    @property
+    def repeated(self) -> bool:
+        return False  # maps cannot be repeated
+
+
+@dataclass
+class EnumDefinitionCompiler(MessageCompiler):
+    """Representation of a proto Enum definition."""
+
+    proto_obj: EnumDescriptorProto = PLACEHOLDER
+    entries: List["EnumDefinitionCompiler.EnumEntry"] = PLACEHOLDER
+
+    @dataclass(unsafe_hash=True)
+    class EnumEntry:
+        """Representation of an Enum entry."""
+
+        name: str
+        value: int
+        comment: str
+
+    def __post_init__(self) -> None:
+        # Get entries/allowed values for this Enum
+        self.entries = [
+            self.EnumEntry(
+                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]
+                ),
+            )
+            for entry_number, entry_proto_value in enumerate(self.proto_obj.value)
+        ]
+        super().__post_init__()  # call MessageCompiler __post_init__
+
+    @property
+    def default_value_string(self) -> str:
+        """Python representation of the default value for Enums.
+
+        As per the spec, this is the first value of the Enum.
+        """
+        return str(self.entries[0].value)  # ideally, should ALWAYS be int(0)!
+
+
+@dataclass
+class ServiceCompiler(ProtoContentBase):
+    parent: OutputTemplate = PLACEHOLDER
+    proto_obj: DescriptorProto = PLACEHOLDER
+    path: List[int] = PLACEHOLDER
+    methods: List["ServiceMethodCompiler"] = field(default_factory=list)
+
+    def __post_init__(self) -> None:
+        # Add service to output file
+        self.output_file.services.append(self)
+        super().__post_init__()  # check for unset fields
+
+    @property
+    def proto_name(self) -> str:
+        return self.proto_obj.name
+
+    @property
+    def py_name(self) -> str:
+        return pythonize_class_name(self.proto_name)
+
+
+@dataclass
+class ServiceMethodCompiler(ProtoContentBase):
+
+    parent: ServiceCompiler
+    proto_obj: MethodDescriptorProto
+    path: List[int] = PLACEHOLDER
+    comment_indent: int = 8
+
+    def __post_init__(self) -> None:
+        # 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")
+        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:
+            self.output_file.typing_imports.add("AsyncIterator")
+
+        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."""
+        return pythonize_method_name(self.proto_obj.name)
+
+    @property
+    def proto_name(self) -> str:
+        """Original protobuf name."""
+        return self.proto_obj.name
+
+    @property
+    def route(self) -> str:
+        return f"/{self.output_file.package}.{self.parent.proto_name}/{self.proto_name}"
+
+    @property
+    def py_input_message(self) -> Optional[MessageCompiler]:
+        """Find the input message object.
+
+        Returns
+        -------
+        Optional[MessageCompiler]
+            Method instance representing the input message.
+            If not input message could be found or there are no
+            input messages, None is returned.
+        """
+        package, name = parse_source_type_name(self.proto_obj.input_type)
+
+        # Nested types are currently flattened without dots.
+        # Todo: keep a fully quantified name in types, that is
+        # comparable with method.input_type
+        for msg in self.request.all_messages:
+            if (
+                msg.py_name == name.replace(".", "")
+                and msg.output_file.package == package
+            ):
+                return msg
+        return None
+
+    @property
+    def py_input_message_type(self) -> str:
+        """String representation of the Python type corresponding to the
+        input message.
+
+        Returns
+        -------
+        str
+            String representation of the Python type corresponding to the input message.
+        """
+        return get_type_reference(
+            package=self.output_file.package,
+            imports=self.output_file.imports,
+            source_type=self.proto_obj.input_type,
+        ).strip('"')
+
+    @property
+    def py_output_message_type(self) -> str:
+        """String representation of the Python type corresponding to the
+        output message.
+
+        Returns
+        -------
+        str
+            String representation of the Python type corresponding to the output message.
+        """
+        return get_type_reference(
+            package=self.output_file.package,
+            imports=self.output_file.imports,
+            source_type=self.proto_obj.output_type,
+            unwrap=False,
+        ).strip('"')
+
+    @property
+    def client_streaming(self) -> bool:
+        return self.proto_obj.client_streaming
+
+    @property
+    def server_streaming(self) -> bool:
+        return self.proto_obj.server_streaming

src/betterproto/plugin/parser.py

@@ -0,0 +1,176 @@
+import itertools
+import pathlib
+import sys
+from typing import TYPE_CHECKING, Iterator, List, Tuple, Union, Set
+
+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 .compiler import outputfile_compiler
+from .models import (
+    EnumDefinitionCompiler,
+    FieldCompiler,
+    MapEntryCompiler,
+    MessageCompiler,
+    OneOfFieldCompiler,
+    OutputTemplate,
+    PluginRequestCompiler,
+    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]]]":
+    # Todo: Keep information about nested hierarchy
+    def _traverse(
+        path: List[int], items: List["Descriptor"], prefix=""
+    ) -> Iterator[Tuple[Union[str, EnumDescriptorProto], List[int]]]:
+        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]
+
+            if isinstance(item, DescriptorProto):
+                for enum in item.enum_type:
+                    enum.name = next_prefix + enum.name
+                    yield enum, path + [i, 4]
+
+                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)
+    )
+
+
+def generate_code(
+    request: plugin.CodeGeneratorRequest, response: plugin.CodeGeneratorResponse
+) -> None:
+    plugin_options = request.parameter.split(",") if request.parameter else []
+
+    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
+            request_data.output_packages[output_package_name] = OutputTemplate(
+                parent_request=request_data, package_proto_obj=proto_file
+            )
+        # Add this input file to the output corresponding to this package
+        request_data.output_packages[output_package_name].input_files.append(proto_file)
+
+    # 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 Services
+    for output_package_name, output_package in request_data.output_packages.items():
+        for proto_input_file in output_package.input_files:
+            for index, service in enumerate(proto_input_file.service):
+                read_protobuf_service(service, index, output_package)
+
+    # Generate output files
+    output_paths: Set[pathlib.Path] = set()
+    for output_package_name, output_package in request_data.output_packages.items():
+
+        # 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)
+
+    # 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
+    } - output_paths
+
+    for init_file in init_files:
+        init = response.file.add()
+        init.name = str(init_file)
+
+    for output_package_name in sorted(output_paths.union(init_files)):
+        print(f"Writing {output_package_name}", file=sys.stderr)
+
+
+def read_protobuf_type(
+    item: DescriptorProto, path: List[int], 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)
+        for index, field in enumerate(item.field):
+            if is_map(field, item):
+                MapEntryCompiler(
+                    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]
+                )
+            else:
+                FieldCompiler(
+                    parent=message_data, proto_obj=field, path=path + [2, index]
+                )
+    elif isinstance(item, EnumDescriptorProto):
+        # Enum
+        EnumDefinitionCompiler(parent=output_package, proto_obj=item, path=path)
+
+
+def read_protobuf_service(
+    service: ServiceDescriptorProto, index: int, output_package: OutputTemplate
+) -> None:
+    service_data = ServiceCompiler(
+        parent=output_package, proto_obj=service, path=[6, index]
+    )
+    for j, method in enumerate(service.method):
+        ServiceMethodCompiler(
+            parent=service_data, proto_obj=method, path=[6, index, 2, j]
+        )

src/betterproto/plugin/plugin.bat

@@ -0,0 +1,2 @@
+@SET plugin_dir=%~dp0
+@python -m %plugin_dir% %*

src/betterproto/templates/template.py.j2

@@ -0,0 +1,159 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# sources: {{ ', '.join(output_file.input_filenames) }}
+# plugin: python-betterproto
+{% for i in output_file.python_module_imports|sort %}
+import {{ i }}
+{% endfor %}
+from dataclasses import dataclass
+{% if output_file.datetime_imports %}
+from datetime import {% for i in output_file.datetime_imports|sort %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
+
+{% endif%}
+{% if output_file.typing_imports %}
+from typing import {% for i in output_file.typing_imports|sort %}{{ i }}{% if not loop.last %}, {% endif %}{% endfor %}
+
+{% endif %}
+
+import betterproto
+{% if output_file.services %}
+import grpclib
+{% endif %}
+
+
+{% if output_file.enums %}{% for enum in output_file.enums %}
+class {{ enum.py_name }}(betterproto.Enum):
+    {% if enum.comment %}
+{{ enum.comment }}
+
+    {% endif %}
+    {% for entry in enum.entries %}
+        {% if entry.comment %}
+{{ entry.comment }}
+        {% endif %}
+    {{ entry.name }} = {{ entry.value }}
+    {% endfor %}
+
+
+{% endfor %}
+{% endif %}
+{% for message in output_file.messages %}
+@dataclass(eq=False, repr=False)
+class {{ message.py_name }}(betterproto.Message):
+    {% if message.comment %}
+{{ message.comment }}
+
+    {% endif %}
+    {% for field in message.fields %}
+        {% if field.comment %}
+{{ field.comment }}
+        {% endif %}
+    {{ field.get_field_string() }}
+    {% endfor %}
+    {% if not message.fields %}
+    pass
+    {% endif %}
+
+    {% if message.deprecated or message.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 }}:
+            warnings.warn("{{ message.py_name }}.{{ field }} is deprecated", DeprecationWarning)
+        {% endfor %}
+    {%  endif %}
+
+
+{% endfor %}
+{% for service in output_file.services %}
+class {{ service.py_name }}Stub(betterproto.ServiceStub):
+    {% 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 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 -%}
+        {%- else -%}
+            {# Client streaming: need a request iterator instead #}
+            , request_iterator: Union[AsyncIterable["{{ method.py_input_message_type }}"], Iterable["{{ 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 %}
+        {%- 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_type }},
+            {{ method.py_output_message_type.strip('"') }},
+        ):
+            yield response
+            {% else %}{# i.e. not client streaming #}
+        async for response in self._unary_stream(
+            "{{ method.route }}",
+            request,
+            {{ method.py_output_message_type.strip('"') }},
+        ):
+            yield response
+
+            {% endif %}{# if client streaming #}
+        {% else %}{# i.e. not server streaming #}
+            {% if method.client_streaming %}
+        return await self._stream_unary(
+            "{{ method.route }}",
+            request_iterator,
+            {{ method.py_input_message_type }},
+            {{ method.py_output_message_type.strip('"') }}
+        )
+            {% else %}{# i.e. not client streaming #}
+        return await self._unary_unary(
+            "{{ method.route }}",
+            request,
+            {{ method.py_output_message_type.strip('"') }}
+        )
+            {% endif %}{# client streaming #}
+        {% endif %}
+
+    {% endfor %}
+{% endfor %}
+
+{% for i in output_file.imports|sort %}
+{{ i }}
+{% endfor %}

tests/README.md

@@ -50,7 +50,7 @@ You can add multiple `.proto` files to the test case, as long as one file matche
 `test_<name>.py` &mdash; *Custom test to validate specific aspects of the generated class*
 
 ```python
-from betterproto.tests.output_betterproto.bool.bool import Test
+from tests.output_betterproto.bool.bool import Test
 
 def test_value():
     message = Test()

tests/generate.py

@@ -2,18 +2,17 @@
 import asyncio
 import os
 from pathlib import Path
+import platform
 import shutil
-import subprocess
 import sys
 from typing import Set
 
-from betterproto.tests.util import (
+from tests.util import (
     get_directories,
     inputs_path,
     output_path_betterproto,
     output_path_reference,
-    protoc_plugin,
-    protoc_reference,
+    protoc,
 )
 
 # Force pure-python implementation instead of C++, otherwise imports
@@ -89,8 +88,8 @@ async def generate_test_case_output(
         (ref_out, ref_err, ref_code),
         (plg_out, plg_err, plg_code),
     ) = await asyncio.gather(
-        protoc_reference(test_case_input_path, test_case_output_path_reference),
-        protoc_plugin(test_case_input_path, test_case_output_path_betterproto),
+        protoc(test_case_input_path, test_case_output_path_reference, True),
+        protoc(test_case_input_path, test_case_output_path_betterproto, False),
     )
 
     message = f"Generated output for {test_case_name!r}"
@@ -136,6 +135,10 @@ def main():
     else:
         verbose = False
         whitelist = set(sys.argv[1:])
+
+    if platform.system() == "Windows":
+        asyncio.set_event_loop(asyncio.ProactorEventLoop())
+
     asyncio.get_event_loop().run_until_complete(generate(whitelist, verbose))
 
 

tests/grpc/test_grpclib_client.py

@@ -1,12 +1,15 @@
 import asyncio
-from betterproto.tests.output_betterproto.service.service import (
-    DoThingResponse,
+import sys
+
+from tests.output_betterproto.service.service import (
     DoThingRequest,
+    DoThingResponse,
     GetThingRequest,
-    GetThingResponse,
     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
@@ -18,31 +21,92 @@ async def _test_client(client, name="clean room", **kwargs):
     assert response.names == [name]
 
 
-def _assert_request_meta_recieved(deadline, metadata):
+def _assert_request_meta_received(deadline, metadata):
     def server_side_test(stream):
         assert stream.deadline._timestamp == pytest.approx(
             deadline._timestamp, 1
-        ), "The provided deadline should be recieved serverside"
+        ), "The provided deadline should be received serverside"
         assert (
             stream.metadata["authorization"] == metadata["authorization"]
-        ), "The provided authorization metadata should be recieved serverside"
+        ), "The provided authorization metadata should be received serverside"
 
     return server_side_test
 
 
+@pytest.fixture
+def handler_trailer_only_unauthenticated():
+    async def handler(stream: grpclib.server.Stream):
+        await stream.recv_message()
+        await stream.send_initial_metadata()
+        await stream.send_trailing_metadata(status=grpclib.Status.UNAUTHENTICATED)
+
+    return handler
+
+
 @pytest.mark.asyncio
 async def test_simple_service_call():
     async with ChannelFor([ThingService()]) as channel:
         await _test_client(ThingServiceClient(channel))
 
 
+@pytest.mark.asyncio
+async def test_trailer_only_error_unary_unary(
+    mocker, handler_trailer_only_unauthenticated
+):
+    service = ThingService()
+    mocker.patch.object(
+        service,
+        "do_thing",
+        side_effect=handler_trailer_only_unauthenticated,
+        autospec=True,
+    )
+    async with ChannelFor([service]) as channel:
+        with pytest.raises(grpclib.exceptions.GRPCError) as e:
+            await ThingServiceClient(channel).do_thing(name="something")
+        assert e.value.status == grpclib.Status.UNAUTHENTICATED
+
+
+@pytest.mark.asyncio
+async def test_trailer_only_error_stream_unary(
+    mocker, handler_trailer_only_unauthenticated
+):
+    service = ThingService()
+    mocker.patch.object(
+        service,
+        "do_many_things",
+        side_effect=handler_trailer_only_unauthenticated,
+        autospec=True,
+    )
+    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")]
+            )
+            await _test_client(ThingServiceClient(channel))
+        assert e.value.status == grpclib.Status.UNAUTHENTICATED
+
+
+@pytest.mark.asyncio
+@pytest.mark.skipif(
+    sys.version_info < (3, 8), reason="async mock spy does works for python3.8+"
+)
+async def test_service_call_mutable_defaults(mocker):
+    async with ChannelFor([ThingService()]) as channel:
+        client = ThingServiceClient(channel)
+        spy = mocker.spy(client, "_unary_unary")
+        await _test_client(client)
+        comments = spy.call_args_list[-1].args[1].comments
+        await _test_client(client)
+        assert spy.call_args_list[-1].args[1].comments is not comments
+
+
 @pytest.mark.asyncio
 async def test_service_call_with_upfront_request_params():
     # Setting deadline
     deadline = grpclib.metadata.Deadline.from_timeout(22)
     metadata = {"authorization": "12345"}
     async with ChannelFor(
-        [ThingService(test_hook=_assert_request_meta_recieved(deadline, metadata),)]
+        [ThingService(test_hook=_assert_request_meta_received(deadline, metadata))]
     ) as channel:
         await _test_client(
             ThingServiceClient(channel, deadline=deadline, metadata=metadata)
@@ -53,7 +117,7 @@ async def test_service_call_with_upfront_request_params():
     deadline = grpclib.metadata.Deadline.from_timeout(timeout)
     metadata = {"authorization": "12345"}
     async with ChannelFor(
-        [ThingService(test_hook=_assert_request_meta_recieved(deadline, metadata),)]
+        [ThingService(test_hook=_assert_request_meta_received(deadline, metadata))]
     ) as channel:
         await _test_client(
             ThingServiceClient(channel, timeout=timeout, metadata=metadata)
@@ -70,7 +134,7 @@ async def test_service_call_lower_level_with_overrides():
     kwarg_deadline = grpclib.metadata.Deadline.from_timeout(28)
     kwarg_metadata = {"authorization": "12345"}
     async with ChannelFor(
-        [ThingService(test_hook=_assert_request_meta_recieved(deadline, metadata),)]
+        [ThingService(test_hook=_assert_request_meta_received(deadline, metadata))]
     ) as channel:
         client = ThingServiceClient(channel, deadline=deadline, metadata=metadata)
         response = await client._unary_unary(
@@ -92,7 +156,7 @@ async def test_service_call_lower_level_with_overrides():
     async with ChannelFor(
         [
             ThingService(
-                test_hook=_assert_request_meta_recieved(kwarg_deadline, kwarg_metadata),
+                test_hook=_assert_request_meta_received(kwarg_deadline, kwarg_metadata),
             )
         ]
     ) as channel:
@@ -140,8 +204,8 @@ async def test_async_gen_for_stream_stream_request():
             assert response.version == response_index + 1
             response_index += 1
             if more_things:
-                # Send some more requests as we recieve reponses to be sure coordination of
-                # send/recieve events doesn't matter
+                # Send some more requests as we receive responses to be sure coordination of
+                # send/receive events doesn't matter
                 await request_chan.send(GetThingRequest(more_things.pop(0)))
             elif not send_initial_requests.done():
                 # Make sure the sending task it completed
@@ -151,4 +215,4 @@ async def test_async_gen_for_stream_stream_request():
                 request_chan.close()
         assert response_index == len(
             expected_things
-        ), "Didn't recieve all exptected responses"
+        ), "Didn't receive all expected responses"

tests/grpc/test_stream_stream.py

@@ -27,10 +27,7 @@ class ClientStub:
 
 
 async def to_list(generator: AsyncIterator):
-    result = []
-    async for value in generator:
-        result.append(value)
-    return result
+    return [value async for value in generator]
 
 
 @pytest.fixture

tests/grpc/thing_service.py

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

tests/inputs/bool/test_bool.py

@@ -1,4 +1,4 @@
-from betterproto.tests.output_betterproto.bool import Test
+from tests.output_betterproto.bool import Test
 
 
 def test_value():

tests/inputs/casing/test_casing.py

@@ -1,5 +1,5 @@
-import betterproto.tests.output_betterproto.casing as casing
-from betterproto.tests.output_betterproto.casing import Test
+import tests.output_betterproto.casing as casing
+from tests.output_betterproto.casing import Test
 
 
 def test_message_attributes():

tests/inputs/casing_message_field_uppercase/casing_message_field_uppercase.py

@@ -1,4 +1,4 @@
-from betterproto.tests.output_betterproto.casing_message_field_uppercase import Test
+from tests.output_betterproto.casing_message_field_uppercase import Test
 
 
 def test_message_casing():

tests/inputs/config.py

@@ -1,13 +1,11 @@
 # Test cases that are expected to fail, e.g. unimplemented features or bug-fixes.
 # Remove from list when fixed.
 xfail = {
-    "import_circular_dependency",
     "oneof_enum",  # 63
     "namespace_keywords",  # 70
     "namespace_builtin_types",  # 53
     "googletypes_struct",  # 9
     "googletypes_value",  # 9
-    "enum_skipped_value",  # 93
     "import_capitalized_package",
     "example",  # This is the example in the readme. Not a test.
 }

tests/inputs/deprecated/deprecated.json

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

tests/inputs/deprecated/deprecated.proto

@@ -0,0 +1,9 @@
+syntax = "proto3";
+
+// Some documentation about the Test message.
+message Test {
+    // Some documentation about the value.
+    option deprecated = true;
+    int32 v = 1 [deprecated=true];
+    int32 value = 2;
+}

tests/inputs/deprecated_field/deprecated_field.json

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

tests/inputs/deprecated_field/deprecated_field.proto

@@ -0,0 +1,8 @@
+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/enum/enum.json

@@ -0,0 +1,9 @@
+{
+  "choice": "FOUR",
+  "choices": [
+    "ZERO",
+    "ONE",
+    "THREE",
+    "FOUR"
+  ]
+}

tests/inputs/enum/enum.proto

@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+// Tests that enums are correctly serialized and that it correctly handles skipped and out-of-order enum values
+message Test {
+  Choice choice = 1;
+  repeated Choice choices = 2;
+}
+
+enum Choice {
+  ZERO = 0;
+  ONE = 1;
+  // TWO = 2;
+  FOUR = 4;
+  THREE = 3;
+}

tests/inputs/enum/test_enum.py

@@ -0,0 +1,84 @@
+from tests.output_betterproto.enum import (
+    Test,
+    Choice,
+)
+
+
+def test_enum_set_and_get():
+    assert Test(choice=Choice.ZERO).choice == Choice.ZERO
+    assert Test(choice=Choice.ONE).choice == Choice.ONE
+    assert Test(choice=Choice.THREE).choice == Choice.THREE
+    assert Test(choice=Choice.FOUR).choice == Choice.FOUR
+
+
+def test_enum_set_with_int():
+    assert Test(choice=0).choice == Choice.ZERO
+    assert Test(choice=1).choice == Choice.ONE
+    assert Test(choice=3).choice == Choice.THREE
+    assert Test(choice=4).choice == Choice.FOUR
+
+
+def test_enum_is_comparable_with_int():
+    assert Test(choice=Choice.ZERO).choice == 0
+    assert Test(choice=Choice.ONE).choice == 1
+    assert Test(choice=Choice.THREE).choice == 3
+    assert Test(choice=Choice.FOUR).choice == 4
+
+
+def test_enum_to_dict():
+    assert (
+        "choice" not in Test(choice=Choice.ZERO).to_dict()
+    ), "Default enum value is not serialized"
+    assert (
+        Test(choice=Choice.ZERO).to_dict(include_default_values=True)["choice"]
+        == "ZERO"
+    )
+    assert Test(choice=Choice.ONE).to_dict()["choice"] == "ONE"
+    assert Test(choice=Choice.THREE).to_dict()["choice"] == "THREE"
+    assert Test(choice=Choice.FOUR).to_dict()["choice"] == "FOUR"
+
+
+def test_repeated_enum_is_comparable_with_int():
+    assert Test(choices=[Choice.ZERO]).choices == [0]
+    assert Test(choices=[Choice.ONE]).choices == [1]
+    assert Test(choices=[Choice.THREE]).choices == [3]
+    assert Test(choices=[Choice.FOUR]).choices == [4]
+
+
+def test_repeated_enum_set_and_get():
+    assert Test(choices=[Choice.ZERO]).choices == [Choice.ZERO]
+    assert Test(choices=[Choice.ONE]).choices == [Choice.ONE]
+    assert Test(choices=[Choice.THREE]).choices == [Choice.THREE]
+    assert Test(choices=[Choice.FOUR]).choices == [Choice.FOUR]
+
+
+def test_repeated_enum_to_dict():
+    assert Test(choices=[Choice.ZERO]).to_dict()["choices"] == ["ZERO"]
+    assert Test(choices=[Choice.ONE]).to_dict()["choices"] == ["ONE"]
+    assert Test(choices=[Choice.THREE]).to_dict()["choices"] == ["THREE"]
+    assert Test(choices=[Choice.FOUR]).to_dict()["choices"] == ["FOUR"]
+
+    all_enums_dict = Test(
+        choices=[Choice.ZERO, Choice.ONE, Choice.THREE, Choice.FOUR]
+    ).to_dict()
+    assert (all_enums_dict["choices"]) == ["ZERO", "ONE", "THREE", "FOUR"]
+
+
+def test_repeated_enum_with_single_value_to_dict():
+    assert Test(choices=Choice.ONE).to_dict()["choices"] == ["ONE"]
+    assert Test(choices=1).to_dict()["choices"] == ["ONE"]
+
+
+def test_repeated_enum_with_non_list_iterables_to_dict():
+    assert Test(choices=(1, 3)).to_dict()["choices"] == ["ONE", "THREE"]
+    assert Test(choices=(1, 3)).to_dict()["choices"] == ["ONE", "THREE"]
+    assert Test(choices=(Choice.ONE, Choice.THREE)).to_dict()["choices"] == [
+        "ONE",
+        "THREE",
+    ]
+
+    def enum_generator():
+        yield Choice.ONE
+        yield Choice.THREE
+
+    assert Test(choices=enum_generator()).to_dict()["choices"] == ["ONE", "THREE"]

tests/inputs/google_impl_behavior_equivalence/google_impl_behavior_equivalence.proto

@@ -0,0 +1,13 @@
+syntax = "proto3";
+
+message Foo{
+  int64 bar = 1;
+}
+
+message Test{
+  oneof group{
+    string string = 1;
+    int64 integer = 2;
+    Foo foo = 3;
+  }
+}

tests/inputs/google_impl_behavior_equivalence/test_google_impl_behavior_equivalence.py

@@ -0,0 +1,55 @@
+import pytest
+
+from google.protobuf import json_format
+import betterproto
+from tests.output_betterproto.google_impl_behavior_equivalence import (
+    Test,
+    Foo,
+)
+from tests.output_reference.google_impl_behavior_equivalence.google_impl_behavior_equivalence_pb2 import (
+    Test as ReferenceTest,
+    Foo as ReferenceFoo,
+)
+
+
+def test_oneof_serializes_similar_to_google_oneof():
+
+    tests = [
+        (Test(string="abc"), ReferenceTest(string="abc")),
+        (Test(integer=2), ReferenceTest(integer=2)),
+        (Test(foo=Foo(bar=1)), ReferenceTest(foo=ReferenceFoo(bar=1))),
+        # Default values should also behave the same within oneofs
+        (Test(string=""), ReferenceTest(string="")),
+        (Test(integer=0), ReferenceTest(integer=0)),
+        (Test(foo=Foo(bar=0)), ReferenceTest(foo=ReferenceFoo(bar=0))),
+    ]
+    for message, message_reference in tests:
+        # NOTE: As of July 2020, MessageToJson inserts newlines in the output string so,
+        # just compare dicts
+        assert message.to_dict() == json_format.MessageToDict(message_reference)
+
+
+def test_bytes_are_the_same_for_oneof():
+
+    message = Test(string="")
+    message_reference = ReferenceTest(string="")
+
+    message_bytes = bytes(message)
+    message_reference_bytes = message_reference.SerializeToString()
+
+    assert message_bytes == message_reference_bytes
+
+    message2 = Test().parse(message_reference_bytes)
+    message_reference2 = ReferenceTest()
+    message_reference2.ParseFromString(message_reference_bytes)
+
+    assert message == message2
+    assert message_reference == message_reference2
+
+    # 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 isinstance(message_reference.foo, ReferenceFoo)
+    assert isinstance(message_reference2.foo, ReferenceFoo)

tests/inputs/googletypes_response/test_googletypes_response.py

@@ -3,8 +3,8 @@ from typing import Any, Callable, Optional
 import betterproto.lib.google.protobuf as protobuf
 import pytest
 
-from betterproto.tests.mocks import MockChannel
-from betterproto.tests.output_betterproto.googletypes_response import TestStub
+from tests.mocks import MockChannel
+from tests.output_betterproto.googletypes_response import TestStub
 
 test_cases = [
     (TestStub.get_double, protobuf.DoubleValue, 2.5),
@@ -21,7 +21,7 @@ test_cases = [
 
 @pytest.mark.asyncio
 @pytest.mark.parametrize(["service_method", "wrapper_class", "value"], test_cases)
-async def test_channel_recieves_wrapped_type(
+async def test_channel_receives_wrapped_type(
     service_method: Callable[[TestStub], Any], wrapper_class: Callable, value
 ):
     wrapped_value = wrapper_class()

tests/inputs/googletypes_response_embedded/test_googletypes_response_embedded.py

@@ -1,7 +1,7 @@
 import pytest
 
-from betterproto.tests.mocks import MockChannel
-from betterproto.tests.output_betterproto.googletypes_response_embedded import (
+from tests.mocks import MockChannel
+from tests.output_betterproto.googletypes_response_embedded import (
     Output,
     TestStub,
 )