Fix some types (#1162)

Fix some issues discovered by running ty on the codebase.

Author: adamchainz

src/django_mysql/models/fields/dynamic.py

@@ -28,8 +28,10 @@
 
 try:
     import mariadb_dyncol
+
+    HAVE_MARIADB_DYNCOL = True
 except ImportError:  # pragma: no cover
-    mariadb_dyncol = None
+    HAVE_MARIADB_DYNCOL = False
 
 
 # Mypy doesn't support recursive types at time of writing, but we can at least
@@ -87,7 +89,7 @@ def check(self, **kwargs: Any) -> list[checks.CheckMessage]:
 
     def _check_mariadb_dyncol(self) -> list[checks.CheckMessage]:
         errors = []
-        if mariadb_dyncol is None:
+        if not HAVE_MARIADB_DYNCOL:
             errors.append(
                 checks.Error(
                     "'mariadb_dyncol' is required to use DynamicField",

src/django_mysql/models/functions.py

@@ -182,7 +182,7 @@ def __init__(
         self,
         expression: ExpressionArgument,
         *paths: ExpressionArgument,
-        output_field: type[DjangoField] | None = None,
+        output_field: DjangoField | None = None,
     ) -> None:
         exprs = [expression]
         for path in paths:

src/django_mysql/operations.py

@@ -2,7 +2,7 @@
 
 from django.db.backends.base.schema import BaseDatabaseSchemaEditor
 from django.db.migrations.operations.base import Operation
-from django.db.migrations.state import ModelState
+from django.db.migrations.state import ProjectState
 from django.utils.functional import cached_property
 
 
@@ -15,15 +15,15 @@ def __init__(self, name: str, soname: str) -> None:
         self.name = name
         self.soname = soname
 
-    def state_forwards(self, app_label: str, state: ModelState) -> None:
+    def state_forwards(self, app_label: str, state: ProjectState) -> None:
         pass  # pragma: no cover
 
     def database_forwards(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        from_st: ModelState,
-        to_st: ModelState,
+        from_state: ProjectState,
+        to_state: ProjectState,
     ) -> None:
         if not self.plugin_installed(schema_editor):
             schema_editor.execute(
@@ -34,8 +34,8 @@ def database_backwards(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        from_st: ModelState,
-        to_st: ModelState,
+        from_state: ProjectState,
+        to_state: ProjectState,
     ) -> None:
         if self.plugin_installed(schema_editor):
             schema_editor.execute(f"UNINSTALL PLUGIN {self.name}")
@@ -63,24 +63,24 @@ class InstallSOName(Operation):
     def __init__(self, soname: str) -> None:
         self.soname = soname
 
-    def state_forwards(self, app_label: str, state: ModelState) -> None:
+    def state_forwards(self, app_label: str, state: ProjectState) -> None:
         pass  # pragma: no cover
 
     def database_forwards(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        from_st: ModelState,
-        to_st: ModelState,
+        from_state: ProjectState,
+        to_state: ProjectState,
     ) -> None:
         schema_editor.execute("INSTALL SONAME %s", (self.soname,))
 
     def database_backwards(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        from_st: ModelState,
-        to_st: ModelState,
+        from_state: ProjectState,
+        to_state: ProjectState,
     ) -> None:
         schema_editor.execute("UNINSTALL SONAME %s", (self.soname,))
 
@@ -100,24 +100,24 @@ def __init__(
     def reversible(self) -> bool:
         return self.from_engine is not None
 
-    def state_forwards(self, app_label: str, state: ModelState) -> None:
+    def state_forwards(self, app_label: str, state: ProjectState) -> None:
         pass
 
     def database_forwards(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        from_state: ModelState,
-        to_state: ModelState,
+        from_state: ProjectState,
+        to_state: ProjectState,
     ) -> None:
         self._change_engine(app_label, schema_editor, to_state, engine=self.engine)
 
     def database_backwards(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        from_state: ModelState,
-        to_state: ModelState,
+        from_state: ProjectState,
+        to_state: ProjectState,
     ) -> None:
         if self.from_engine is None:
             raise NotImplementedError("You cannot reverse this operation")
@@ -128,7 +128,7 @@ def _change_engine(
         self,
         app_label: str,
         schema_editor: BaseDatabaseSchemaEditor,
-        to_state: ModelState,
+        to_state: ProjectState,
         engine: str,
     ) -> None:
         new_model = to_state.apps.get_model(app_label, self.name)

src/django_mysql/utils.py

@@ -131,7 +131,9 @@ def collapse_spaces(string: str) -> str:
     return " ".join(filter(None, bits))
 
 
-def index_name(model: Model, *field_names: str, using: str = DEFAULT_DB_ALIAS) -> str:
+def index_name(
+    model: type[Model], *field_names: str, using: str = DEFAULT_DB_ALIAS
+) -> str:
     """
     Returns the name of the index existing on field_names, or raises KeyError
     if no such index exists.

tests/testapp/test_dynamicfield.py

@@ -313,7 +313,7 @@ class Valid(models.Model):
         assert errors[0].id == "django_mysql.E013"
         assert "MariaDB is required" in errors[0].msg
 
-    @mock.patch(DynamicField.__module__ + ".mariadb_dyncol", new=None)
+    @mock.patch(DynamicField.__module__ + ".HAVE_MARIADB_DYNCOL", new=False)
     def test_mariadb_dyncol_missing(self):
         errors = DynamicModel.check()
         assert len(errors) == 1

tests/testapp/test_size_fields.py

@@ -46,7 +46,7 @@ def test_binaryfield_default_length(self):
         # By default, SizedBinaryField should act like BinaryField
         field = SizedBinaryField()
         assert field.size_class == 4
-        assert field.db_type(None) == "longblob"
+        assert field.db_type(connection) == "longblob"
 
     @atomic
     def test_binary_1_max_length(self):
@@ -149,7 +149,7 @@ def test_textfield_default_length(self):
         # By default, SizedTextField should act like TextField
         field = SizedTextField()
         assert field.size_class == 4
-        assert field.db_type(None) == "longtext"
+        assert field.db_type(connection) == "longtext"
 
     def test_tinytext_max_length(self):
         # Okay