Modernize ClassView and ModelView (#433)

ClassView's legacy architecture dating to the Python 2.7 era has been thoroughly revised for Py3, with full static type checking support. Coincidental fixes in other modules that were noticed during the overhaul are also included.

docs/conf.py

@@ -16,7 +16,7 @@
 import typing as t
 
 sys.path.insert(0, os.path.abspath('../src'))
-from coaster import _version  # isort:skip  # pylint: disable=wrong-import-position
+from coaster import _version  # isort:skip
 
 # 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

src/coaster/app.py

@@ -40,7 +40,7 @@
 mod_tomli: t.Optional[types.ModuleType] = None
 mod_yaml: t.Optional[types.ModuleType] = None
 
-try:  # pragma: no cover
+try:
     import toml as mod_toml  # type: ignore[no-redef,unused-ignore]
 except ModuleNotFoundError:
     try:
@@ -52,7 +52,7 @@
             pass
 
 
-try:  # pragma: no cover
+try:
     import yaml as mod_yaml
 except ModuleNotFoundError:
     pass
@@ -106,7 +106,7 @@ class ConfigLoader(NamedTuple):
 # --- Key rotation wrapper -------------------------------------------------------------
 
 
-class KeyRotationWrapper(t.Generic[_S]):  # pylint: disable=too-few-public-methods
+class KeyRotationWrapper(t.Generic[_S]):
     """
     Wrapper to support multiple secret keys in itsdangerous.
 
@@ -193,7 +193,7 @@ class JSONProvider(DefaultJSONProvider):
 
     @staticmethod
     def default(o: t.Any) -> t.Any:
-        """Expand default support to check for `__json__`."""
+        """Expand default support to check for a ``__json__`` method."""
         if hasattr(o, '__json__'):
             return o.__json__()
         if isinstance(o, abc.Mapping):
@@ -330,11 +330,10 @@ def load_config_from_file(
     try:
         if load is None:
             return app.config.from_pyfile(filepath)
-        # The `text` parameter requires Flask 2.3. We still support Flask 2.2
+        # The `text` parameter was introduced in Flask 2.3, but its default value
+        # may change in a future release, so we only supply a value if we have a bool
         if text is not None:
-            return app.config.from_file(  # type: ignore[call-arg]
-                filepath, load=load, text=text
-            )
+            return app.config.from_file(filepath, load=load, text=text)
         return app.config.from_file(filepath, load=load)
     except OSError:
         app.logger.warning(

src/coaster/auth.py

@@ -23,7 +23,8 @@
 from threading import Lock
 from typing import cast
 
-from flask import Flask, current_app, g, request
+from flask import Flask, current_app, g
+from flask.globals import request_ctx
 from werkzeug.local import LocalProxy
 from werkzeug.wrappers import Response as BaseResponse
 
@@ -108,9 +109,9 @@ def request_has_auth() -> bool:
     to set cookies or perform other housekeeping functions.
     """
     return (
-        bool(request)
-        and hasattr(request, '_current_auth')
-        and 'actor' in request._current_auth.__dict__
+        bool(request_ctx)
+        and hasattr(request_ctx, 'current_auth')
+        and 'actor' in request_ctx.current_auth.__dict__
     )
 
 
@@ -162,10 +163,10 @@ def __setattr__(self, attr: str, value: t.Any) -> t.NoReturn:
             # This test is used to allow in-place mutations such as:
             # current_auth.permissions |= {extra}
             return  # type: ignore[misc]
-        raise AttributeError('CurrentAuth is read-only')
+        raise TypeError('current_auth is read-only')
 
     def __delattr__(self, attr: str) -> t.NoReturn:
-        raise AttributeError('CurrentAuth is read-only')
+        raise TypeError('current_auth is read-only')
 
     def __contains__(self, attr: str) -> bool:
         """Check for presence of an attribute."""
@@ -197,12 +198,12 @@ def __getattr__(self, attr: str) -> t.Any:
     def _call_login_manager(self) -> None:
         """Call the app's login manager on first access of user or actor (internal)."""
         # Check for an existing user from Flask-Login
-        if not request:
+        if not request_ctx:
             # There's no request context for a login manager to operate on
             return
         # If there's no existing user, look for a login manager
         if (
-            request
+            request_ctx
             and hasattr(current_app, 'login_manager')
             and hasattr(current_app.login_manager, '_load_user')
         ):
@@ -258,13 +259,14 @@ def init_app(app: Flask) -> None:
 def _get_current_auth() -> CurrentAuth:
     """Provide current_auth for the request context."""
     # 1. Do we have a request context?
-    if request:
+    if request_ctx:
         with _get_lock:
             # 2. Does this request already have current_auth? If so, return it
-            ca = getattr(request, '_current_auth', None)
+            ca = getattr(request_ctx, 'current_auth', None)
             if ca is None:
                 # 3. If not, create it
-                request._current_auth = ca = CurrentAuth()  # type: ignore[attr-defined]
+                ca = CurrentAuth()
+                request_ctx.current_auth = ca  # type: ignore[attr-defined]
         # 4. Return current_auth
         return ca
 

src/coaster/db.py

@@ -19,12 +19,12 @@
 
 from .sqlalchemy import Query
 
-try:  # pragma: no cover
+try:
     from psycopg2.extensions import connection as Psycopg2Connection  # noqa: N812
 except ModuleNotFoundError:
     Psycopg2Connection = None
 
-try:  # pragma: no cover
+try:
     from psycopg import Connection as Psycopg3Connection
 except ModuleNotFoundError:
     Psycopg3Connection = None  # type: ignore[assignment,misc]

src/coaster/logger.py

@@ -32,7 +32,7 @@
 from flask import g, request, session
 from flask.config import Config
 
-try:  # Flask >= 3.0  # pragma: no cover
+try:  # Flask >= 3.0
     from flask.sansio.app import App as FlaskApp
 except ModuleNotFoundError:
     from flask import Flask as FlaskApp

src/coaster/sqlalchemy/functions.py

@@ -87,17 +87,17 @@ def make_timestamp_columns(
 
 
 @overload
-def failsafe_add(__session: session_type, __instance: t.Any) -> None:
+def failsafe_add(__session: session_type, __instance: t.Any, /) -> None:
     ...
 
 
 @overload
-def failsafe_add(__session: session_type, __instance: T, **filters: t.Any) -> T:
+def failsafe_add(__session: session_type, __instance: T, /, **filters: t.Any) -> T:
     ...
 
 
 def failsafe_add(
-    __session: session_type, __instance: T, **filters: t.Any
+    __session: session_type, __instance: T, /, **filters: t.Any
 ) -> t.Optional[T]:
     """
     Add and commit a new instance in a nested transaction (using SQL SAVEPOINT).

src/coaster/sqlalchemy/markdown.py

@@ -92,10 +92,6 @@ def __eq__(self, other: t.Any) -> bool:
             self.__composite_values__() == other.__composite_values__()
         )
 
-    def __ne__(self, other: t.Any) -> bool:
-        """Compare for inequality."""
-        return not self.__eq__(other)
-
     # Pickle support methods implemented as per SQLAlchemy documentation, but not
     # tested here as we don't use them.
     # https://docs.sqlalchemy.org/en/13/orm/extensions/mutable.html#id1