Add testcase with Concatenate

Author: sterliakov

test-data/unit/check-classes.test

@@ -7808,9 +7808,107 @@ reveal_type(A().g2)  # E: Invalid self argument "A" to attribute function "g2" w
                      # N: Revealed type is "def ()"
 reveal_type(A().g3)  # E: Invalid self argument "A" to attribute function "g3" with type "Callable[[int], None]" \
                      # N: Revealed type is "def ()"
+[builtins fixtures/tuple.pyi]
+
+[case testMethodSelfArgumentChecksConcatenate]
+from typing import Callable, ParamSpec, TypeVar
+from typing_extensions import Concatenate
+
+T = TypeVar("T")
+P = ParamSpec("P")
+R = TypeVar("R")
+
+def to_same_callable(fn: Callable[Concatenate[T, P], R]) -> Callable[Concatenate[T, P], R]:
+    return fn
+
+def remove_first(fn: Callable[Concatenate[T, P], R]) -> Callable[P, R]:
+    ...
+
+def add_correct_first(fn: Callable[P, R]) -> Callable[Concatenate["C", P], R]:
+    ...
 
+def add_wrong_first(fn: Callable[P, R]) -> Callable[Concatenate[int, P], R]:
+    ...
 
+class A:
+    @to_same_callable  # E: Argument 1 to "to_same_callable" has incompatible type "Callable[[], int]"; expected "Callable[[T], int]"
+    def fn1() -> int:
+        return 0
+
+    @to_same_callable
+    def fn2(_x: int) -> int:  # E: Self argument missing for a non-static method (or an invalid type for self)
+        return 0
+
+    @to_same_callable
+    def fn3(self, _x: int) -> int:
+        return 0
+
+reveal_type(A().fn1)  # N: Revealed type is "def () -> builtins.int"
+reveal_type(A().fn2)  # E: Invalid self argument "A" to attribute function "fn2" with type "Callable[[int], int]" \
+                      # N: Revealed type is "def () -> builtins.int"
+reveal_type(A().fn3)  # N: Revealed type is "def (_x: builtins.int) -> builtins.int"
+
+class B:
+    @remove_first  # E: Argument 1 to "remove_first" has incompatible type "Callable[[], int]"; expected "Callable[[T], int]"
+    def fn1() -> int:  # E: Method must have at least one argument. Did you forget the "self" argument?
+        return 0
+
+    @remove_first
+    def fn2(_x: int) -> int:  # E: Method must have at least one argument. Did you forget the "self" argument?
+        return 0
+
+    @remove_first
+    def fn3(self, _x: int) -> int:  # E: Self argument missing for a non-static method (or an invalid type for self)
+        return 0
+
+    @remove_first
+    def fn4(self, new_self: 'B') -> int:
+        return 0
+
+reveal_type(B().fn1)  # E: Attribute function "fn1" with type "Callable[[], int]" does not accept self argument \
+                      # N: Revealed type is "def () -> builtins.int"
+reveal_type(B().fn2)  # E: Attribute function "fn2" with type "Callable[[], int]" does not accept self argument \
+                      # N: Revealed type is "def () -> builtins.int"
+reveal_type(B().fn3)  # E: Invalid self argument "B" to attribute function "fn3" with type "Callable[[int], int]" \
+                      # N: Revealed type is "def () -> builtins.int"
+reveal_type(B().fn4)  # N: Revealed type is "def () -> builtins.int"
+
+class C:
+    @add_correct_first
+    def fn1() -> int:
+        return 0
+
+    @add_correct_first
+    def fn2(_x: int) -> int:
+        return 0
+
+    @add_correct_first
+    def fn3(self, _x: int) -> int:
+        return 0
+
+reveal_type(C().fn1)  # N: Revealed type is "def () -> builtins.int"
+reveal_type(C().fn2)  # N: Revealed type is "def (_x: builtins.int) -> builtins.int"
+reveal_type(C().fn3)  # N: Revealed type is "def (self: __main__.C, _x: builtins.int) -> builtins.int"
+
+class D:
+    @add_wrong_first
+    def fn1() -> int:  # E: Self argument missing for a non-static method (or an invalid type for self)
+        return 0
+
+    @add_wrong_first
+    def fn2(_x: int) -> int:  # E: Self argument missing for a non-static method (or an invalid type for self)
+        return 0
+
+    @add_wrong_first
+    def fn3(self, _x: int) -> int:  # E: Self argument missing for a non-static method (or an invalid type for self)
+        return 0
 
+reveal_type(D().fn1)  # E: Invalid self argument "D" to attribute function "fn1" with type "Callable[[int], int]" \
+                      # N: Revealed type is "def () -> builtins.int"
+reveal_type(D().fn2)  # E: Invalid self argument "D" to attribute function "fn2" with type "Callable[[int, int], int]" \
+                      # N: Revealed type is "def (_x: builtins.int) -> builtins.int"
+reveal_type(D().fn3)  # E: Invalid self argument "D" to attribute function "fn3" with type "Callable[[int, D, int], int]" \
+                      # N: Revealed type is "def (self: __main__.D, _x: builtins.int) -> builtins.int"
 [builtins fixtures/tuple.pyi]
 
 [case testTypeAfterAttributeAccessWithDisallowAnyExpr]