fix: deprecation warning when passing parser to Command.__init__ (#2010)

news/2007.bugfix.md

@@ -0,0 +1 @@
+Pop up a warning when the deprecated `parser` argument is passed to `BaseCommand.__init__()` method.

src/pdm/cli/commands/base.py

@@ -1,11 +1,13 @@
 from __future__ import annotations
 
 import argparse
+import inspect
 from argparse import _SubParsersAction
 from typing import Any, TypeVar
 
 from pdm.cli.options import Option, global_option, project_option, verbose_option
 from pdm.project import Project
+from pdm.utils import deprecation_warning
 
 C = TypeVar("C", bound="BaseCommand")
 
@@ -21,12 +23,16 @@ class BaseCommand:
     # Rewrite this if you don't want the default ones
     arguments: list[Option] = [verbose_option, global_option, project_option]
 
-    def __init__(self, parser: argparse.ArgumentParser | None = None) -> None:
-        """For compatibility, the parser is optional and won't be used."""
-
     @classmethod
     def init_parser(cls: type[C], parser: argparse.ArgumentParser) -> C:
-        cmd = cls()
+        args = inspect.signature(cls).parameters
+        if "parser" in args:
+            deprecation_warning(
+                f"The `parser` argument of `{cls.__name__}.__init__()` is deprecated. It won't be used."
+            )
+            cmd = cls(parser)  # type: ignore[call-arg]
+        else:
+            cmd = cls()
         for arg in cmd.arguments:
             arg.add_to_parser(parser)
         cmd.add_arguments(parser)