prefer version with any

Author: hauntsaninja

mypy/join.py

@@ -414,6 +414,9 @@ def visit_callable_type(self, t: CallableType) -> ProperType:
                     # We don't want to return unusable Callable, attempt fallback instead.
                     return join_types(t.fallback, self.s)
             else:
+                s, t = self.s, t
+                if s.min_args < t.min_args:
+                    s, t = t, s
                 if is_subtype(self.s, t):
                     result = t.copy_modified()
                 elif is_subtype(t, self.s):

test-data/unit/check-functions.test

@@ -3499,12 +3499,12 @@ def f_any(*_, **__): ...
 def f_3(common, b=None, x=None): ...
 
 fdict = {
-    "f_1": f_1,  # E: Dict entry 0 has incompatible type "str": "Callable[[Any, Any], Any]"; expected "str": "Callable[[Any, Any, Any], Any]"
+    "f_1": f_1,
     "f_any": f_any,
     "f_3": f_3,
 }
-reveal_type(fdict)  # N: Revealed type is "builtins.dict[builtins.str, def (common: Any, b: Any =, x: Any =) -> Any]"
+reveal_type(fdict)  # N: Revealed type is "builtins.dict[builtins.str, def (*_: Any, **__: Any) -> Any]"
+
+reveal_type(join(f_1, f_any, f_3))  # N: Revealed type is "def (*_: Any, **__: Any) -> Any"
 
-reveal_type(join(f_1, f_any, f_3))  # N: Revealed type is "def (common: Any, b: Any =, x: Any =) -> Any" \
-                                    # E: Argument 1 to "join" has incompatible type "Callable[[Any, Any], Any]"; expected "Callable[[Any, Any, Any], Any]"
 [builtins fixtures/tuple.pyi]