Fix message when second argument to isinstance is an alias to Any (python#7504)

ckarnell · JukkaL · commit 8782ae7f789a · 2019-09-16T17:10:46.000+03:00
Fixes python#7478.
diff --git a/mypy/checkexpr.py b/mypy/checkexpr.py
@@ -272,8 +272,8 @@ def visit_call_expr_inner(self, e: CallExpr, allow_none_return: bool = False) ->
         if (isinstance(e.callee, NameExpr) and e.callee.name in ('isinstance', 'issubclass')
                 and len(e.args) == 2):
             for typ in mypy.checker.flatten(e.args[1]):
+                node = None
                 if isinstance(typ, NameExpr):
-                    node = None
                     try:
                         node = self.chk.lookup_qualified(typ.name)
                     except KeyError:
@@ -282,6 +282,10 @@ def visit_call_expr_inner(self, e: CallExpr, allow_none_return: bool = False) ->
                 if is_expr_literal_type(typ):
                     self.msg.cannot_use_function_with_type(e.callee.name, "Literal", e)
                     continue
+                if (node and isinstance(node.node, TypeAlias)
+                        and isinstance(get_proper_type(node.node.target), AnyType)):
+                    self.msg.cannot_use_function_with_type(e.callee.name, "Any", e)
+                    continue
                 if ((isinstance(typ, IndexExpr)
                         and isinstance(typ.analyzed, (TypeApplication, TypeAliasExpr)))
                         or (isinstance(typ, NameExpr) and node and
diff --git a/mypy/messages.py b/mypy/messages.py
@@ -1124,7 +1124,7 @@ def concrete_only_call(self, typ: Type, context: Context) -> None:
 
     def cannot_use_function_with_type(
             self, method_name: str, type_name: str, context: Context) -> None:
-        self.fail("Cannot use {}() with a {} type".format(method_name, type_name), context)
+        self.fail("Cannot use {}() with {} type".format(method_name, type_name), context)
 
     def report_non_method_protocol(self, tp: TypeInfo, members: List[str],
                                    context: Context) -> None:
diff --git a/test-data/unit/check-isinstance.test b/test-data/unit/check-isinstance.test
@@ -1753,6 +1753,12 @@ isinstance(x, (int, (str, Iterable[int])))  # E: Parameterized generics cannot b
 [builtins fixtures/isinstancelist.pyi]
 [typing fixtures/typing-full.pyi]
 
+[case testIsinstanceAnyAlias]
+from typing import Any
+A = Any
+isinstance(object(), A)  # E: Cannot use isinstance() with Any type
+[builtins fixtures/isinstance.pyi]
+
 [case testIsinstanceTypeArgsAliases]
 from typing import Iterable, TypeVar
 x = 1
diff --git a/test-data/unit/check-literal.test b/test-data/unit/check-literal.test
@@ -1767,17 +1767,17 @@ import typing_extensions as indirect
 
 Alias = Literal[3]
 
-isinstance(3, Literal[3])           # E: Cannot use isinstance() with a Literal type
-isinstance(3, Alias)                # E: Cannot use isinstance() with a Literal type \
+isinstance(3, Literal[3])           # E: Cannot use isinstance() with Literal type
+isinstance(3, Alias)                # E: Cannot use isinstance() with Literal type \
                                     # E: The type alias to Literal is invalid in runtime context
-isinstance(3, Renamed[3])           # E: Cannot use isinstance() with a Literal type
-isinstance(3, indirect.Literal[3])  # E: Cannot use isinstance() with a Literal type
+isinstance(3, Renamed[3])           # E: Cannot use isinstance() with Literal type
+isinstance(3, indirect.Literal[3])  # E: Cannot use isinstance() with Literal type
 
-issubclass(int, Literal[3])           # E: Cannot use issubclass() with a Literal type
-issubclass(int, Alias)                # E: Cannot use issubclass() with a Literal type \
+issubclass(int, Literal[3])           # E: Cannot use issubclass() with Literal type
+issubclass(int, Alias)                # E: Cannot use issubclass() with Literal type \
                                       # E: The type alias to Literal is invalid in runtime context
-issubclass(int, Renamed[3])           # E: Cannot use issubclass() with a Literal type
-issubclass(int, indirect.Literal[3])  # E: Cannot use issubclass() with a Literal type
+issubclass(int, Renamed[3])           # E: Cannot use issubclass() with Literal type
+issubclass(int, indirect.Literal[3])  # E: Cannot use issubclass() with Literal type
 [builtins fixtures/isinstancelist.pyi]
 [out]
 
diff --git a/test-data/unit/check-newtype.test b/test-data/unit/check-newtype.test
@@ -366,9 +366,9 @@ Any(5)
 from typing import NewType
 T = NewType('T', int)
 d: object
-if isinstance(d, T):   # E: Cannot use isinstance() with a NewType type
+if isinstance(d, T):   # E: Cannot use isinstance() with NewType type
     reveal_type(d)     # N: Revealed type is '__main__.T'
-issubclass(object, T)  # E: Cannot use issubclass() with a NewType type
+issubclass(object, T)  # E: Cannot use issubclass() with NewType type
 [builtins fixtures/isinstancelist.pyi]
 
 [case testInvalidNewTypeCrash]
diff --git a/test-data/unit/check-typeddict.test b/test-data/unit/check-typeddict.test
@@ -740,9 +740,9 @@ def set_coordinate(p: TaggedPoint, key: str, value: int) -> None:
 from mypy_extensions import TypedDict
 D = TypedDict('D', {'x': int})
 d: object
-if isinstance(d, D):   # E: Cannot use isinstance() with a TypedDict type
+if isinstance(d, D):   # E: Cannot use isinstance() with TypedDict type
     reveal_type(d)     # N: Revealed type is '__main__.D'
-issubclass(object, D)  # E: Cannot use issubclass() with a TypedDict type
+issubclass(object, D)  # E: Cannot use issubclass() with TypedDict type
 [builtins fixtures/isinstancelist.pyi]
 
 
