Check names of positional arguments for @OverRide

tmke8 · May 8, 2023 · 94840af · 94840af
1 parent 10cd4aa
commit 94840af
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Showing 2 changed files with 10 additions and 4 deletions.
diff --git a/mypy/checker.py b/mypy/checker.py
@@ -1971,6 +1971,9 @@ def check_method_override_for_base_with_name(
                     original_class_or_static,
                     override_class_or_static,
                     context,
+                    ignore_pos_arg_names=(
+                        not context.is_explicit_override if isinstance(context, FuncDef) else True
+                    ),
                 )
             elif is_equivalent(original_type, typ):
                 # Assume invariance for a non-callable attribute here. Note
@@ -2058,6 +2061,7 @@ def check_override(
         original_class_or_static: bool,
         override_class_or_static: bool,
         node: Context,
+        ignore_pos_arg_names: bool,
     ) -> None:
         """Check a method override with given signatures.
 
@@ -2071,7 +2075,7 @@ def check_override(
         # Use boolean variable to clarify code.
         fail = False
         op_method_wider_note = False
-        if not is_subtype(override, original, ignore_pos_arg_names=True):
+        if not is_subtype(override, original, ignore_pos_arg_names=ignore_pos_arg_names):
             fail = True
         elif isinstance(override, Overloaded) and self.is_forward_op_method(name):
             # Operator method overrides cannot extend the domain, as

diff --git a/test-data/unit/check-functions.test b/test-data/unit/check-functions.test
@@ -2742,9 +2742,11 @@ class B(A):
 
 class C(A):
     @override
-    def f(self, x: str) -> str: pass  # E: Argument 1 of "f" is incompatible with supertype "A"; supertype defines the argument type as "int" \
-                                      # N: This violates the Liskov substitution principle \
-                                      # N: See https://mypy.readthedocs.io/en/stable/common_issues.html#incompatible-overrides
+    def f(self, y: int) -> str: pass  # E: Signature of "f" incompatible with supertype "A" \
+                                      # N:      Superclass:               \
+                                      # N:          def f(self, x: int) -> str \
+                                      # N:      Subclass:                 \
+                                      # N:          def f(self, y: int) -> str
     def g(self, x: int) -> str: pass
 
 class D(A): pass