Added error test case for overloaded custom __init__

Author: uko3211

test-data/unit/check-plugin-attrs.test

@@ -2498,43 +2498,32 @@ reveal_type(c.run_type)  # N: Revealed type is "Union[builtins.int, None]"
 [builtins fixtures/plugin_attrs.pyi]
 
 [case testAttrsInitOverload1]
-from typing import Union
+# flags: --python-version 3.10
 from typing import overload
 
 import attrs
 
 @attrs.frozen(init=False)
 class C:
-    x: Union[int, str]
+    x: "int | str"
+
     @overload
     def __init__(self, x: int) -> None: ...
 
     @overload
     def __init__(self, x: str) -> None: ...
 
-    def __init__(self, x: Union[int, str]) -> None:
+    def __init__(self, x: "int | str") -> None:
         self.__attrs_init__(x)
 
+
 obj = C(1)
-attrs.evolve(obj, x=2)
+attrs.evolve(obj, x=2) # E: Argument 1 to "evolve" has incompatible type "C"; expected an attrs class
+attrs.evolve(obj, x="2") # E: Argument 1 to "evolve" has incompatible type "C"; expected an attrs class
 [builtins fixtures/plugin_attrs.pyi]
 
 [case testAttrsInitOverload2]
-from typing import Union
-import attrs
-
-@attrs.frozen(init=False)
-class C:
-    x: Union[int, str]
-
-    def __init__(self, x: Union[int, str], y: bool) -> None:
-        self.__attrs_init__(x)
-
-obj = C(1, False)
-attrs.evolve(obj, x=2)
-[builtins fixtures/plugin_attrs.pyi]
-
-[case testAttrsInitOverload3]
+# flags: --python-version 3.10
 from typing import overload
 
 import attrs
@@ -2553,5 +2542,5 @@ class C:
         self.__attrs_init__(x)
 
 obj = C(1)
-attrs.evolve(obj, x=2)
-[builtins fixtures/plugin_attrs.pyi]
+attrs.evolve(obj, x=2) # E: Argument 1 to "evolve" has incompatible type "C"; expected an attrs class
+[builtins fixtures/plugin_attrs.pyi]