New semantic analyzer: add tests for casts and type application (python#6566)

msullivan · web-flow · commit bcd04807e534 · 2019-03-18T17:36:59.000-07:00
It seems like they already work fine? Closes python#6291, python#6292.
diff --git a/test-data/unit/check-newsemanal.test b/test-data/unit/check-newsemanal.test
@@ -1540,6 +1540,8 @@ strict_optional = True
 [[mypy-b]
 strict_optional = False
 
+-- ]]
+
 [case testNewAnalyzerProperty]
 class A:
     @property
@@ -1920,3 +1922,78 @@ reveal_type(y[0])  # E: Revealed type is 'builtins.int'
 x: A
 reveal_type(x)  # E: Revealed type is '__main__.G[Tuple[builtins.int, fallback=__main__.C]]'
 [builtins fixtures/list.pyi]
+
+[case testNewAnalyzerCastForward1]
+from typing import cast
+
+x = cast('C', None)
+class A:
+    def foo(self) -> None:
+        self.x = cast('C', None)
+
+reveal_type(x)  # E: Revealed type is '__main__.C'
+reveal_type(A().x)  # E: Revealed type is '__main__.C'
+
+class C(A): ...
+
+[case testNewAnalyzerCastForward2]
+from typing import cast
+
+x = cast('C', None)
+
+reveal_type(x)  # E: Revealed type is 'builtins.int'
+
+C = int
+
+[case testNewAnalyzerCastForward2]
+from typing import cast, NamedTuple
+
+x = cast('C', None)
+
+reveal_type(x)  # E: Revealed type is 'Tuple[builtins.int, fallback=__main__.C]'
+reveal_type(x.x)  # E: Revealed type is 'builtins.int'
+
+C = NamedTuple('C', [('x', int)])
+
+[case testNewAnalyzerApplicationForward1]
+from typing import Generic, TypeVar
+
+x = C[int]()
+reveal_type(x)  # E: Revealed type is '__main__.C[builtins.int*]'
+
+T = TypeVar('T')
+class C(Generic[T]): ...
+
+[case testNewAnalyzerApplicationForward2]
+from typing import Generic, TypeVar
+
+T = TypeVar('T')
+class C(Generic[T]): ...
+
+x = C['A']()
+reveal_type(x)  # E: Revealed type is '__main__.C[__main__.A*]'
+
+class A: ...
+
+[case testNewAnalyzerApplicationForward3]
+from typing import Generic, TypeVar
+
+x = C[A]()
+reveal_type(x)  # E: Revealed type is '__main__.C[__main__.A*]'
+
+T = TypeVar('T')
+class C(Generic[T]): ...
+
+class A: ...
+
+[case testNewAnalyzerApplicationForward4]
+from typing import Generic, TypeVar
+
+x = C[A]()  # E: Value of type variable "T" of "C" cannot be "A"
+reveal_type(x)  # E: Revealed type is '__main__.C[__main__.A*]'
+
+T = TypeVar('T', bound='D')
+class C(Generic[T]): ...
+
+class A: ...
+class D: ...
