Move to pyright (#172)

Following a discussion we have decided to move our static type checking from mypy to pyright. Pyright is a more complete checker, catching many things mypy missed, and is also more strongly supported, being a Microsoft library.

.dockerignore

@@ -1,5 +1,4 @@
 **/.devcontainer
-**/.mypy_cache
 **/.pytest_cache
 **/.tox
 **/.venv

.github/CONTRIBUTING.rst

@@ -33,7 +33,7 @@ The code in this repository conforms to standards set by the following tools:
 - black_ for code formatting
 - flake8_ for style checks
 - isort_ for import ordering
-- mypy_ for static type checking
+- pyright_ for static type checking
 
 Developers guide
 ----------------

.github/workflows/code.yml

@@ -27,7 +27,7 @@ jobs:
           install_options: -e .[dev]
 
       - name: Lint
-        run: tox -e pre-commit,mypy
+        run: tox -e pre-commit,pyright
 
   test:
     if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.repository

.gitignore

@@ -45,7 +45,6 @@ nosetests.xml
 coverage.xml
 cov.xml
 .pytest_cache/
-.mypy_cache/
 
 # Translations
 *.mo

.vscode/settings.json

@@ -1,15 +1,18 @@
 {
+    "python.languageServer": "Pylance",
+    "python.analysis.typeCheckingMode": "basic",
+    "python.analysis.diagnosticSeverityOverrides": {
+        "reportMissingModuleSource": "none"
+    },
     "editor.defaultFormatter": "ms-python.python",
+    "python.linting.enabled": true,
     "python.linting.pylintEnabled": false,
     "python.linting.flake8Enabled": true,
-    "python.linting.mypyEnabled": true,
     "python.linting.pydocstyleEnabled": true,
-    "python.linting.enabled": true,
     "python.testing.pytestArgs": [],
     "python.testing.unittestEnabled": false,
     "python.testing.pytestEnabled": true,
     "python.formatting.provider": "black",
-    "python.languageServer": "Pylance",
     "editor.formatOnSave": true,
     "editor.codeActionsOnSave": {
         "source.organizeImports": true

docs/conf.py

@@ -122,7 +122,7 @@
 .. _black: https://github.com/psf/black
 .. _flake8: https://flake8.pycqa.org/en/latest/
 .. _isort: https://github.com/PyCQA/isort
-.. _mypy: http://mypy-lang.org/
+.. _pyright: https://microsoft.github.io/pyright/#/
 .. _pre-commit: https://pre-commit.com/
 """
 

docs/developer/how-to/static-analysis.rst

@@ -1,8 +1,8 @@
-Run static analysis using mypy
-==============================
+Run static analysis using pyright
+=================================
 
-Static type analysis is done with mypy_. It checks type definition in source
+Static type analysis is done with pyright_. It checks type definition in source
 files without running them, and highlights potential issues where types do not
 match. You can run it with::
 
-    $ tox -e mypy
+    $ tox -e pyright

docs/developer/reference/standards.rst

@@ -12,7 +12,7 @@ The code in this repository conforms to standards set by the following tools:
 - black_ for code formatting
 - flake8_ for style checks
 - isort_ for import ordering
-- mypy_ for static type checking
+- pyright_ for static type checking
 
 .. seealso::
 

pyproject.toml

@@ -32,14 +32,13 @@ requires-python = ">=3.9"
 [project.optional-dependencies]
 dev = [
     "black",
-    "mypy",
+    "pyright",
     "flake8-isort",
     "Flake8-pyproject",
     "pipdeptree",
     "pre-commit",
     "pydata-sphinx-theme>=0.12",
     "pytest-cov",
-    "pytest-mypy",
     "pytest-flake8",
     "pytest-black",
     "pytest-asyncio",
@@ -68,8 +67,8 @@ name = "Callum Forrester"
 [tool.setuptools_scm]
 write_to = "src/tickit/_version.py"
 
-[tool.mypy]
-ignore_missing_imports = true # Ignore missing stubs in imported modules
+[tool.pyright]
+reportMissingImports = false # Ignore missing stubs in imported modules
 
 [tool.isort]
 float_to_top = true
@@ -122,19 +121,19 @@ legacy_tox_ini = """
 [tox]
 skipsdist=True
 
-[testenv:{pre-commit,mypy,pytest,docs}]
+[testenv:{pre-commit,pyright,pytest,docs}]
 # Don't create a virtualenv for the command, requires tox-direct plugin
 direct = True
 passenv = *
 allowlist_externals =
     pytest
     pre-commit
-    mypy
+    pyright
     sphinx-build
     sphinx-autobuild
 commands =
     pytest: pytest {posargs}
-    mypy: mypy src tests {posargs}
+    pyright: pyright src tests {posargs}
     pre-commit: pre-commit run --all-files {posargs}
     docs: sphinx-{posargs:build -EW --keep-going} -T docs build/html
 """

src/tickit/adapters/interpreters/endpoints/http_endpoint.py

@@ -27,8 +27,6 @@ class HttpEndpoint(Generic[AnyStr]):
     method: str
     interrupt: bool = False
 
-    # Type signature can become more specific if support is dropped for
-    # Python 3.7, see https://github.com/python/mypy/issues/708
     def __call__(self, func: Callable) -> Callable:
         """Decorate a function for HTTP routing.
 

src/tickit/core/adapter.py

@@ -18,7 +18,6 @@
 T = TypeVar("T")
 
 
-# https://github.com/python/mypy/issues/708#issuecomment-647124281
 class RaiseInterrupt(Protocol):
     """A raise_interrupt function that should be passed to `Adapter`."""