Add mypy config to gradually roll out types

Add mypy config to gradually roll out types in the code base. The
configured tox environment will not run unless explicitly specified
(with tox -e types).

The mypy config will ignore all files that have not been opted in,
allowing a gradual roll out through the codebase.

pyproject.toml

@@ -8,3 +8,33 @@ line_length = 120
 
 [tool.black]
 line-length = 120
+
+[tool.mypy]
+ignore_missing_imports = true
+warn_unused_configs = true
+disallow_any_generics = true
+disallow_subclassing_any = true
+# disallow_untyped_calls = true # temp disabled
+disallow_untyped_defs = true
+disallow_incomplete_defs = true
+check_untyped_defs = true
+disallow_untyped_decorators = true
+no_implicit_optional = true
+warn_redundant_casts = true
+warn_unused_ignores = true
+warn_return_any = true
+no_implicit_reexport = true
+strict_equality = true
+plugins = "sqlmypy"
+
+# Gradually roll out mypy by ignoring all files not explicitly opted in.
+[[tool.mypy.overrides]]
+module = "comet_core.*"
+ignore_errors = true
+
+[[tool.mypy.overrides]]
+module = [
+  "comet_core.data_store",
+  "comet_core.models"
+]
+ignore_errors = false

requirements-dev.txt

@@ -1,7 +1,18 @@
+# Install the package itself in dev mode
+-e .
+
+tox==3.24.1
+
+# Formatters and linters
 black==21.7b0
+pylint==2.9.6
+isort==5.8.0
+
+# Testing
 pytest==6.2.4
 pytest-cov==2.12.0
 pytest-freezegun==0.4.2
-tox==3.24.1
-pylint==2.9.6
-isort==5.8.0
+
+# Types
+mypy==0.910
+sqlalchemy-stubs==0.4

tox.ini

@@ -33,5 +33,13 @@ commands =
 [testenv:lint]
 basepython = python3.6
 deps = -rrequirements-dev.txt
+skip_install = true
 commands =
     python3 -m pylint --rcfile={toxinidir}/.pylintrc {toxinidir}/comet_core {toxinidir}/tests
+
+[testenv:types]
+basepython = python3.6
+deps = -rrequirements-dev.txt
+skip_install = true
+commands =
+  python3 -m mypy --config {toxinidir}/pyproject.toml {toxinidir}/comet_core