[PyMySQL] Fix stubs for pymysql.connections.Connection.__init__ (#14724)

Author: JanEricNitschke

stubs/PyMySQL/@tests/stubtest_allowlist.txt

@@ -1,7 +1,3 @@
 # DictCursorMixin changes method types of inherited classes, but doesn't contain much at runtime
 pymysql.cursors.DictCursorMixin.__iter__
 pymysql.cursors.DictCursorMixin.fetch[a-z]*
-
-# FIXME: new stubtest errors from mypy v1.18.1 that need to be looked at more closely.
-# See https://github.com/python/typeshed/pull/14699
-pymysql.connections.Connection.__init__

stubs/PyMySQL/@tests/test_cases/check_connection.py

@@ -0,0 +1,15 @@
+from typing_extensions import assert_type
+
+from pymysql.connections import Connection
+from pymysql.cursors import Cursor
+
+
+class MyCursor(Cursor):
+    pass
+
+
+assert_type(Connection(), Connection[Cursor])
+assert_type(Connection(cursorclass=Cursor), Connection[Cursor])
+assert_type(Connection(cursorclass=MyCursor), Connection[MyCursor])
+
+Connection(cursorclass=None)  # type: ignore

stubs/PyMySQL/pymysql/connections.pyi

@@ -2,8 +2,8 @@ from _typeshed import FileDescriptorOrPath, Incomplete, Unused
 from collections.abc import Callable, Mapping
 from socket import _Address, socket as _socket
 from ssl import SSLContext, _PasswordType
-from typing import Any, AnyStr, Generic, TypeVar, overload
-from typing_extensions import Self, deprecated
+from typing import Any, AnyStr, Generic, overload
+from typing_extensions import Self, TypeVar, deprecated
 
 from .charset import charset_by_id as charset_by_id, charset_by_name as charset_by_name
 from .constants import CLIENT as CLIENT, COMMAND as COMMAND, FIELD_TYPE as FIELD_TYPE, SERVER_STATUS as SERVER_STATUS
@@ -21,7 +21,7 @@ from .err import (
     Warning,
 )
 
-_C = TypeVar("_C", bound=Cursor)
+_C = TypeVar("_C", bound=Cursor, default=Cursor)
 _C2 = TypeVar("_C2", bound=Cursor)
 
 SSL_ENABLED: bool
@@ -61,7 +61,7 @@ class Connection(Generic[_C]):
 
     @overload
     def __init__(
-        self: Connection[Cursor],  # different between overloads
+        self,
         *,
         user: str | bytes | None = None,
         password: str | bytes = "",
@@ -76,7 +76,7 @@ class Connection(Generic[_C]):
         conv: dict[int | type[Any], Callable[[Any], str] | Callable[[str], Any]] | None = None,
         use_unicode: bool = True,
         client_flag: int = 0,
-        cursorclass: None = None,  # different between overloads
+        cursorclass: type[_C] = ...,
         init_command: str | None = None,
         connect_timeout: float = 10,
         read_default_group: str | None = None,
@@ -106,104 +106,9 @@ class Connection(Generic[_C]):
         db: None = None,  # deprecated
     ) -> None: ...
     @overload
-    def __init__(
-        # different between overloads
-        self: Connection[_C],  # pyright: ignore[reportInvalidTypeVarUse]  #11780
-        *,
-        user: str | bytes | None = None,
-        password: str | bytes = "",
-        host: str | None = None,
-        database: str | bytes | None = None,
-        unix_socket: _Address | None = None,
-        port: int = 0,
-        charset: str = "",
-        collation: str | None = None,
-        sql_mode: str | None = None,
-        read_default_file: str | None = None,
-        conv: dict[int | type[Any], Callable[[Any], str] | Callable[[str], Any]] | None = None,
-        use_unicode: bool = True,
-        client_flag: int = 0,
-        cursorclass: type[_C] = ...,  # different between overloads
-        init_command: str | None = None,
-        connect_timeout: float = 10,
-        read_default_group: str | None = None,
-        autocommit: bool | None = False,
-        local_infile: bool = False,
-        max_allowed_packet: int = 16_777_216,
-        defer_connect: bool = False,
-        auth_plugin_map: dict[str, Callable[[Connection[Any]], Any]] | None = None,
-        read_timeout: float | None = None,
-        write_timeout: float | None = None,
-        bind_address: str | None = None,
-        binary_prefix: bool = False,
-        program_name: str | None = None,
-        server_public_key: bytes | None = None,
-        ssl: dict[str, Incomplete] | SSLContext | None = None,
-        ssl_ca: str | None = None,
-        ssl_cert: str | None = None,
-        ssl_disabled: bool | None = None,
-        ssl_key: str | None = None,
-        ssl_key_password: _PasswordType | None = None,
-        ssl_verify_cert: bool | None = None,
-        ssl_verify_identity: bool | None = None,
-        compress: Unused = None,
-        named_pipe: Unused = None,
-        # different between overloads:
-        passwd: None = None,  # deprecated
-        db: None = None,  # deprecated
-    ) -> None: ...
-    @overload
-    @deprecated("'passwd' and 'db' arguments are deprecated. Use 'password' and 'database' instead.")
-    def __init__(
-        self: Connection[Cursor],  # different between overloads
-        *,
-        user: str | bytes | None = None,
-        password: str | bytes = "",
-        host: str | None = None,
-        database: str | bytes | None = None,
-        unix_socket: _Address | None = None,
-        port: int = 0,
-        charset: str = "",
-        collation: str | None = None,
-        sql_mode: str | None = None,
-        read_default_file: str | None = None,
-        conv: dict[int | type[Any], Callable[[Any], str] | Callable[[str], Any]] | None = None,
-        use_unicode: bool = True,
-        client_flag: int = 0,
-        cursorclass: None = None,  # different between overloads
-        init_command: str | None = None,
-        connect_timeout: float = 10,
-        read_default_group: str | None = None,
-        autocommit: bool | None = False,
-        local_infile: bool = False,
-        max_allowed_packet: int = 16_777_216,
-        defer_connect: bool = False,
-        auth_plugin_map: dict[str, Callable[[Connection[Any]], Any]] | None = None,
-        read_timeout: float | None = None,
-        write_timeout: float | None = None,
-        bind_address: str | None = None,
-        binary_prefix: bool = False,
-        program_name: str | None = None,
-        server_public_key: bytes | None = None,
-        ssl: dict[str, Incomplete] | SSLContext | None = None,
-        ssl_ca: str | None = None,
-        ssl_cert: str | None = None,
-        ssl_disabled: bool | None = None,
-        ssl_key: str | None = None,
-        ssl_key_password: _PasswordType | None = None,
-        ssl_verify_cert: bool | None = None,
-        ssl_verify_identity: bool | None = None,
-        compress: Unused = None,
-        named_pipe: Unused = None,
-        # different between overloads:
-        passwd: str | bytes | None = None,  # deprecated
-        db: str | bytes | None = None,  # deprecated
-    ) -> None: ...
-    @overload
     @deprecated("'passwd' and 'db' arguments are deprecated. Use 'password' and 'database' instead.")
     def __init__(
-        # different between overloads
-        self: Connection[_C],  # pyright: ignore[reportInvalidTypeVarUse]  #11780
+        self,
         *,
         user: str | bytes | None = None,
         password: str | bytes = "",
@@ -218,7 +123,7 @@ class Connection(Generic[_C]):
         conv: dict[int | type[Any], Callable[[Any], str] | Callable[[str], Any]] | None = None,
         use_unicode: bool = True,
         client_flag: int = 0,
-        cursorclass: type[_C] = ...,  # different between overloads
+        cursorclass: type[_C] = ...,
         init_command: str | None = None,
         connect_timeout: float = 10,
         read_default_group: str | None = None,