Add Python 3.10 to GitHub Actions test matrix (#280)

Co-authored-by: James Hilton-Balfe <50501825+Gobot1234@users.noreply.github.com>

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     strategy:
       matrix:
         os: [Ubuntu, MacOS, Windows]
-        python-version: ['3.6.7', 3.7, 3.8, 3.9]
+        python-version: ['3.6.7', '3.7', '3.8', '3.9', '3.10']
         exclude:
           - os: Windows
             python-version: 3.6

pyproject.toml

@@ -25,10 +25,10 @@ black = "^21.11b0"
 bpython = "^0.19"
 grpcio-tools = "^1.40.0"
 jinja2 = "^2.11.2"
-mypy = "^0.770"
+mypy = "^0.930"
 poethepoet = ">=0.9.0"
 protobuf = "^3.12.2"
-pytest = "^5.4.2"
+pytest = "^6.2.5"
 pytest-asyncio = "^0.12.0"
 pytest-cov = "^2.9.0"
 pytest-mock = "^3.1.1"

src/betterproto/__init__.py

@@ -846,7 +846,7 @@ class Message(ABC):
     @classmethod
     def _type_hints(cls) -> Dict[str, Type]:
         module = sys.modules[cls.__module__]
-        return get_type_hints(cls, vars(module))
+        return get_type_hints(cls, module.__dict__, {})
 
     @classmethod
     def _cls_for(cls, field: dataclasses.Field, index: int = 0) -> Type: