Consistent quote wrapping around MessageBuilder.format as per issue python#3409

Author: Brian Weber

mypy/messages.py

@@ -184,7 +184,7 @@ def format(self, typ: Type, verbosity: int = 0) -> str:
         Mostly behave like format_simple below, but never return an empty string.
         """
         s = self.format_simple(typ, verbosity)
-        if s != '':
+        if s != '' and s != '""':
             # If format_simple returns a non-trivial result, use that.
             return s
         elif isinstance(typ, FunctionLike):
@@ -242,6 +242,9 @@ def format_simple(self, typ: Type, verbosity: int = 0) -> str:
           None -> None
           callable type -> "" (empty string)
         """
+        return '"{}"'.format(self._format_simple(typ, verbosity))
+
+    def _format_simple(self, typ: Type, verbosity: int = 0) -> str:
         if isinstance(typ, Instance):
             itype = typ
             # Get the short name of the type.
@@ -257,7 +260,7 @@ def format_simple(self, typ: Type, verbosity: int = 0) -> str:
                 # No type arguments. Place the type name in quotes to avoid
                 # potential for confusion: otherwise, the type name could be
                 # interpreted as a normal word.
-                return '"{}"'.format(base_str)
+                return base_str
             elif itype.type.fullname() == 'builtins.tuple':
                 item_type_str = strip_quotes(self.format(itype.args[0]))
                 return 'Tuple[{}, ...]'.format(item_type_str)
@@ -281,48 +284,48 @@ def format_simple(self, typ: Type, verbosity: int = 0) -> str:
                     return '{}[...]'.format(base_str)
         elif isinstance(typ, TypeVarType):
             # This is similar to non-generic instance types.
-            return '"{}"'.format(typ.name)
+            return typ.name
         elif isinstance(typ, TupleType):
             # Prefer the name of the fallback class (if not tuple), as it's more informative.
             if typ.fallback.type.fullname() != 'builtins.tuple':
-                return self.format_simple(typ.fallback)
+                return self._format_simple(typ.fallback)
             items = []
             for t in typ.items:
                 items.append(strip_quotes(self.format(t)))
-            s = '"Tuple[{}]"'.format(', '.join(items))
+            s = 'Tuple[{}]'.format(', '.join(items))
             if len(s) < 400:
                 return s
             else:
                 return 'tuple(length {})'.format(len(items))
         elif isinstance(typ, TypedDictType):
             # If the TypedDictType is named, return the name
             if typ.fallback.type.fullname() != 'typing.Mapping':
-                return self.format_simple(typ.fallback)
+                return self._format_simple(typ.fallback)
             items = []
             for (item_name, item_type) in typ.items.items():
                 items.append('{}={}'.format(item_name, strip_quotes(self.format(item_type))))
-            s = '"TypedDict({})"'.format(', '.join(items))
+            s = 'TypedDict({})'.format(', '.join(items))
             return s
         elif isinstance(typ, UnionType):
             # Only print Unions as Optionals if the Optional wouldn't have to contain another Union
             print_as_optional = (len(typ.items) -
                                  sum(isinstance(t, NoneTyp) for t in typ.items) == 1)
             if print_as_optional:
                 rest = [t for t in typ.items if not isinstance(t, NoneTyp)]
-                return '"Optional[{}]"'.format(strip_quotes(self.format(rest[0])))
+                return 'Optional[{}]'.format(strip_quotes(self.format(rest[0])))
             else:
                 items = []
                 for t in typ.items:
                     items.append(strip_quotes(self.format(t)))
-                s = '"Union[{}]"'.format(', '.join(items))
+                s = 'Union[{}]'.format(', '.join(items))
                 if len(s) < 400:
                     return s
                 else:
                     return 'union type ({} items)'.format(len(items))
         elif isinstance(typ, NoneTyp):
             return 'None'
         elif isinstance(typ, AnyType):
-            return '"Any"'
+            return 'Any'
         elif isinstance(typ, DeletedType):
             return '<deleted>'
         elif isinstance(typ, UninhabitedType):
@@ -332,7 +335,7 @@ def format_simple(self, typ: Type, verbosity: int = 0) -> str:
                 return '<nothing>'
         elif isinstance(typ, TypeType):
             return 'Type[{}]'.format(
-                strip_quotes(self.format_simple(typ.item, verbosity)))
+                strip_quotes(self._format_simple(typ.item, verbosity)))
         elif typ is None:
             raise RuntimeError('Type is None')
         else:

test-data/unit/check-async-await.test

@@ -84,7 +84,7 @@ async def f() -> int:
     x = await g()
     return x
 [out]
-main:7: error: Incompatible types in await (actual type Generator[int, None, str], expected type Awaitable[Any])
+main:7: error: Incompatible types in await (actual type "Generator[int, None, str]", expected type "Awaitable[Any]")
 
 [case testAwaitIteratorError]
 
@@ -95,7 +95,7 @@ async def f() -> int:
     x = await g()
     return x
 [out]
-main:6: error: Incompatible types in await (actual type Iterator[Any], expected type Awaitable[Any])
+main:6: error: Incompatible types in await (actual type "Iterator[Any]", expected type "Awaitable[Any]")
 
 [case testAwaitArgumentError]
 
@@ -106,7 +106,7 @@ async def f() -> int:
     return x
 [builtins fixtures/async_await.pyi]
 [out]
-main:5: error: Incompatible types in await (actual type "int", expected type Awaitable[Any])
+main:5: error: Incompatible types in await (actual type "int", expected type "Awaitable[Any]")
 
 [case testAwaitResultError]
 
@@ -150,7 +150,7 @@ async def f() -> None:
 [builtins fixtures/async_await.pyi]
 [out]
 main:4: error: AsyncIterable expected
-main:4: error: List[int] has no attribute "__aiter__"
+main:4: error: "List[int]" has no attribute "__aiter__"
 
 [case testAsyncForTypeComments]
 
@@ -232,13 +232,13 @@ async def wrong_iterable(obj: Iterable[int]):
 
 [out]
 main:18: error: AsyncIterable expected
-main:18: error: Iterable[int] has no attribute "__aiter__"; maybe "__iter__"?
+main:18: error: "Iterable[int]" has no attribute "__aiter__"; maybe "__iter__"?
 main:19: error: Iterable expected
-main:19: error: asyncify[int] has no attribute "__iter__"; maybe "__aiter__"?
+main:19: error: "asyncify[int]" has no attribute "__iter__"; maybe "__aiter__"?
 main:20: error: AsyncIterable expected
-main:20: error: Iterable[int] has no attribute "__aiter__"; maybe "__iter__"?
+main:20: error: "Iterable[int]" has no attribute "__aiter__"; maybe "__iter__"?
 main:21: error: Iterable expected
-main:21: error: asyncify[int] has no attribute "__iter__"; maybe "__aiter__"?
+main:21: error: "asyncify[int]" has no attribute "__iter__"; maybe "__aiter__"?
 [builtins fixtures/async_await.pyi]
 
 [case testAsyncWith]
@@ -271,7 +271,7 @@ class C:
     def __aenter__(self) -> int: pass
     async def __aexit__(self, x, y, z) -> None: pass
 async def f() -> None:
-    async with C() as x:  # E: Incompatible types in "async with" for __aenter__ (actual type "int", expected type Awaitable[Any])
+    async with C() as x:  # E: Incompatible types in "async with" for __aenter__ (actual type "int", expected type "Awaitable[Any]")
         pass
 [builtins fixtures/async_await.pyi]
 [out]
@@ -282,7 +282,7 @@ class C:
     def __aenter__(self) -> None: pass
     async def __aexit__(self, x, y, z) -> None: pass
 async def f() -> None:
-    async with C() as x:  # E: None has no attribute "__await__"
+    async with C() as x:  # E: "None" has no attribute "__await__"
         pass
 [builtins fixtures/async_await.pyi]
 [out]
@@ -293,7 +293,7 @@ class C:
     async def __aenter__(self) -> int: pass
     def __aexit__(self, x, y, z) -> int: pass
 async def f() -> None:
-    async with C() as x: # E: Incompatible types in "async with" for __aexit__ (actual type "int", expected type Awaitable[Any])
+    async with C() as x: # E: Incompatible types in "async with" for __aexit__ (actual type "int", expected type "Awaitable[Any]")
         pass
 [builtins fixtures/async_await.pyi]
 [out]
@@ -304,7 +304,7 @@ class C:
     async def __aenter__(self) -> int: pass
     def __aexit__(self, x, y, z) -> None: pass
 async def f() -> None:
-    async with C() as x: # E: None has no attribute "__await__"
+    async with C() as x: # E: "None" has no attribute "__await__"
         pass
 [builtins fixtures/async_await.pyi]
 [out]
@@ -362,7 +362,7 @@ def g() -> Generator[Any, None, str]:
     return x
 [builtins fixtures/async_await.pyi]
 [out]
-main:6: error: "yield from" can't be applied to Awaitable[str]
+main:6: error: "yield from" can't be applied to "Awaitable[str]"
 
 [case testAwaitableSubclass]
 
@@ -523,7 +523,7 @@ def h() -> None:
 
 [out]
 main:9: error: Iterable expected
-main:9: error: AsyncGenerator[int, None] has no attribute "__iter__"; maybe "__aiter__"?
+main:9: error: "AsyncGenerator[int, None]" has no attribute "__iter__"; maybe "__aiter__"?
 
 [case testAsyncGeneratorNoYieldFrom]
 # flags: --fast-parser --python-version 3.6
@@ -607,19 +607,19 @@ def plain_host_generator() -> Generator[str, None, None]:
     yield 'a'
     x = 0
     x = yield from plain_generator()
-    x = yield from plain_coroutine()  # E: "yield from" can't be applied to Awaitable[int]
+    x = yield from plain_coroutine()  # E: "yield from" can't be applied to "Awaitable[int]"
     x = yield from decorated_generator()
-    x = yield from decorated_coroutine()  # E: "yield from" can't be applied to AwaitableGenerator[Any, Any, int, Awaitable[int]]
+    x = yield from decorated_coroutine()  # E: "yield from" can't be applied to "AwaitableGenerator[Any, Any, int, Awaitable[int]]"
     x = yield from other_iterator()
     x = yield from other_coroutine()  # E: "yield from" can't be applied to "Aw"
 
 async def plain_host_coroutine() -> None:
     x = 0
-    x = await plain_generator()  # E: Incompatible types in await (actual type Generator[str, None, int], expected type Awaitable[Any])
+    x = await plain_generator()  # E: Incompatible types in await (actual type "Generator[str, None, int]", expected type "Awaitable[Any]")
     x = await plain_coroutine()
     x = await decorated_generator()
     x = await decorated_coroutine()
-    x = await other_iterator()  # E: Incompatible types in await (actual type "It", expected type Awaitable[Any])
+    x = await other_iterator()  # E: Incompatible types in await (actual type "It", expected type "Awaitable[Any]")
     x = await other_coroutine()
 
 @coroutine
@@ -636,11 +636,11 @@ def decorated_host_generator() -> Generator[str, None, None]:
 @coroutine
 async def decorated_host_coroutine() -> None:
     x = 0
-    x = await plain_generator()  # E: Incompatible types in await (actual type Generator[str, None, int], expected type Awaitable[Any])
+    x = await plain_generator()  # E: Incompatible types in await (actual type "Generator[str, None, int]", expected type "Awaitable[Any]")
     x = await plain_coroutine()
     x = await decorated_generator()
     x = await decorated_coroutine()
-    x = await other_iterator()  # E: Incompatible types in await (actual type "It", expected type Awaitable[Any])
+    x = await other_iterator()  # E: Incompatible types in await (actual type "It", expected type "Awaitable[Any]")
     x = await other_coroutine()
 
 [builtins fixtures/async_await.pyi]

test-data/unit/check-class-namedtuple.test

@@ -221,7 +221,7 @@ class MyNamedTuple(NamedTuple):
     a: int
     b: str
 
-MyNamedTuple.x # E: Type[MyNamedTuple] has no attribute "x"
+MyNamedTuple.x # E: "Type[MyNamedTuple]" has no attribute "x"
 
 [case testNewNamedTupleEmptyItems]
 # flags: --python-version 3.6
@@ -439,13 +439,13 @@ class HasNone(NamedTuple):
     y: Optional[int] = None
 
 reveal_type(HasNone(1))  # E: Revealed type is 'Tuple[builtins.int, Union[builtins.int, builtins.None], fallback=__main__.HasNone]'
-HasNone(None)  # E: Argument 1 to "HasNone" has incompatible type None; expected "int"
+HasNone(None)  # E: Argument 1 to "HasNone" has incompatible type "None"; expected "int"
 HasNone(1, y=None)
 HasNone(1, y=2)
 
 class CannotBeNone(NamedTuple):
     x: int
-    y: int = None  # E: Incompatible types in assignment (expression has type None, variable has type "int")
+    y: int = None  # E: Incompatible types in assignment (expression has type "None", variable has type "int")
 
 [builtins fixtures/list.pyi]