Add stub for decouple

mypy_stubs/README.md

@@ -0,0 +1,44 @@
+# mypy type hints for 3rd party modules
+
+This folder contains type hints for 3rd party Python modules, used by
+[mypy](https://mypy.readthedocs.io/en/latest/index.html) for static
+analysis of Python code.
+
+## Generation and Maintenance
+
+The files are initially generated with `stubgen` from `mypy`. They can be
+generated for a whole package:
+
+```
+stubgen -o mypy_stubs -p package_name
+```
+
+They can be generated for just one module:
+
+```
+stubgen -o mypy_stubs -m package_name.submodule
+```
+
+Some Django packages require `DJANGO_SETTINGS_MODULE`, or `stubgen` will fail:
+
+```
+export DJANGO_SETTINGS_MODULE=privaterelay.settings
+stubgen -o mypy_stubs -p package_name
+```
+
+The generated stubs are placeholders, and often require significant
+modifications to run without errors. They are also tied to the specific
+version of the package. For this reason, we don't require stubs for
+all third-party packages.
+
+## Documentation
+
+When generating stubs, add a docstring header to the file that specifies the
+`pip` package name and header. This gives us a chance to recognize that the
+stub is out-of-date when updating the package.
+
+Add the same data here:
+
+|package name|version|module name|
+|-:|-:|-:|
+|`python-decouple`|3.6|`decouple`|

mypy_stubs/decouple.pyi

@@ -0,0 +1,100 @@
+"""
+Typing hints for python-decouple 3.6
+
+Generated with:
+stubgen -o mypy_stubs -p decouple
+
+Changes:
+* Comment out globals and classes unused by Relay
+* Add overrides for AutoConfig.__call__ for different scenarios
+* Simplified interfaces of Csv and Choices to our usage
+"""
+
+from pathlib import Path
+from typing import Any, Callable, Sequence, TypeVar, Union, overload
+
+# PYVERSION: Any
+# text_type = str
+# read_config: Any
+# DEFAULT_ENCODING: str
+# TRUE_VALUES: Any
+# FALSE_VALUES: Any
+
+def strtobool(value: Union[str, bool]) -> bool: ...
+
+# class UndefinedValueError(Exception): ...
+class Undefined: ...
+
+# class Config:
+#     repository: Any
+#     def __init__(self, repository) -> None: ...
+#     def get(self, option, default=..., cast=...): ...
+#     def __call__(self, *args, **kwargs): ...
+
+# class RepositoryEmpty:
+#     def __init__(self, source: str = ..., encoding=...) -> None: ...
+#     def __contains__(self, key): ...
+#     def __getitem__(self, key) -> None: ...
+
+# class RepositoryIni(RepositoryEmpty):
+#     SECTION: str
+#     parser: Any
+#     def __init__(self, source, encoding=...) -> None: ...
+#     def __contains__(self, key): ...
+#     def __getitem__(self, key): ...
+
+# class RepositoryEnv(RepositoryEmpty):
+#     data: Any
+#     def __init__(self, source, encoding=...) -> None: ...
+#     def __contains__(self, key): ...
+#     def __getitem__(self, key): ...
+
+# class RepositorySecret(RepositoryEmpty):
+#     data: Any
+#     def __init__(self, source: str = ...) -> None: ...
+#     def __contains__(self, key): ...
+#     def __getitem__(self, key): ...
+
+DefaultType = TypeVar("DefaultType")
+CastRetType = TypeVar("CastRetType")
+
+class AutoConfig:
+    def __init__(self, search_path: Union[str, Path, None] = ...) -> None: ...
+    @overload
+    def __call__(self, option: str) -> str: ...
+    @overload
+    def __call__(self, option: str, default: str) -> str: ...
+    @overload
+    def __call__(
+        self, option: str, default: DefaultType
+    ) -> Union[str, DefaultType]: ...
+    @overload
+    def __call__(
+        self, option: str, cast: Callable[[Any], CastRetType]
+    ) -> CastRetType: ...
+    @overload
+    def __call__(
+        self, option: str, default: Any, cast: Callable[[Any], CastRetType]
+    ) -> CastRetType: ...
+
+config: AutoConfig
+
+class Csv:
+    # Full signature has several optional params
+    # def __init__(
+    #     self, cast=..., delimiter: str = ..., strip=..., post_process=...
+    # ) -> None: ...
+    def __init__(self) -> None: ...
+    def __call__(self, value: str) -> list: ...
+
+class Choices:
+    # Full signature has choices param
+    # def __init__(
+    #     self, flat: Any | None = ..., cast=..., choices: Any | None = ...
+    # ) -> None: ...
+    def __init__(
+        self,
+        flat: Sequence[CastRetType] = ...,
+        cast: Callable[[Any], CastRetType] = ...,
+    ) -> None: ...
+    def __call__(self, value: Any) -> CastRetType: ...

privaterelay/settings.py

@@ -13,6 +13,7 @@ https://docs.djangoproject.com/en/2.2/ref/settings/
 import ipaddress
 import os, sys
 from datetime import datetime
+from typing import Optional
 
 
 from decouple import config, Choices, Csv
@@ -56,7 +57,7 @@ ORIGIN_CHANNEL_MAP = {
 RELAY_CHANNEL = ORIGIN_CHANNEL_MAP.get(SITE_ORIGIN, "prod")
 DEBUG = config("DEBUG", False, cast=bool)
 if DEBUG:
-    INTERNAL_IPS = config("DJANGO_INTERNAL_IPS", default=[])
+    INTERNAL_IPS = config("DJANGO_INTERNAL_IPS", default="", cast=Csv())
 IN_PYTEST = "pytest" in sys.modules
 USE_SILK = DEBUG and HAS_SILK and not IN_PYTEST
 
@@ -418,10 +419,10 @@ PREMIUM_PLAN_COUNTRY_LANG_MAPPING = {
 }
 
 SUBSCRIPTIONS_WITH_UNLIMITED = config("SUBSCRIPTIONS_WITH_UNLIMITED", default="")
-PREMIUM_RELEASE_DATE = config(
+_RAW_PREMIUM_RELEASE_DATE = config(
     "PREMIUM_RELEASE_DATE", "2021-10-27 17:00:00+00:00", cast=str
 )
-PREMIUM_RELEASE_DATE = datetime.fromisoformat(PREMIUM_RELEASE_DATE)
+PREMIUM_RELEASE_DATE = datetime.fromisoformat(_RAW_PREMIUM_RELEASE_DATE)
 
 DOMAIN_REGISTRATION_MODAL = config("DOMAIN_REGISTRATION_MODAL", False, cast=bool)
 MAX_ONBOARDING_AVAILABLE = config("MAX_ONBOARDING_AVAILABLE", 0, cast=int)
@@ -665,7 +666,7 @@ CIRCLE_TAG = config("CIRCLE_TAG", "")
 CIRCLE_BRANCH = config("CIRCLE_BRANCH", "")
 
 if SENTRY_RELEASE:
-    sentry_release = SENTRY_RELEASE
+    sentry_release: Optional[str] = SENTRY_RELEASE
 elif CIRCLE_TAG and CIRCLE_TAG != "unknown":
     sentry_release = CIRCLE_TAG
 elif (

pyproject.toml

@@ -1,5 +1,6 @@
 [tool.mypy]
 plugins = ["mypy_django_plugin.main"]
+mypy_path = "$MYPY_CONFIG_FILE_DIR/mypy_stubs"
 python_version = "3.9"
 show_error_codes = true
 warn_return_any = true
@@ -22,7 +23,6 @@ module = [
     "botocore.exceptions",
     "codetiming",
     "debug_toolbar",
-    "decouple",
     "dj_database_url",
     "django_filters",
     "django_ftl.bundles",