Fail-fast on missing builtins (#14550)

ikonst · web-flow · commit f31d162415c9 · 2023-01-30T01:20:36.000-08:00
As discussed in #14547, some mypy features were degrading rather than failing-fast when certain built-in types (list, dict) were not present in the test environment. - The degraded state (e.g. lack of `__annotations__`) didn't make the culprit (sparse fixture) obvious, making tests harder to debug. - Having the code work around quirks of the testing environment ("sparse fixtures") is an anti-pattern.
diff --git a/mypy/messages.py b/mypy/messages.py
@@ -122,8 +122,6 @@
 # test-data/unit/fixtures/) that provides the definition. This is used for
 # generating better error messages when running mypy tests only.
 SUGGESTED_TEST_FIXTURES: Final = {
-    "builtins.list": "list.pyi",
-    "builtins.dict": "dict.pyi",
     "builtins.set": "set.pyi",
     "builtins.tuple": "tuple.pyi",
     "builtins.bool": "bool.pyi",
diff --git a/mypy/semanal.py b/mypy/semanal.py
@@ -625,23 +625,23 @@ def add_implicit_module_attrs(self, file_node: MypyFile) -> None:
                     continue
                 # Need to construct the type ourselves, to avoid issues with __builtins__.list
                 # not being subscriptable or typing.List not getting bound
-                sym = self.lookup_qualified("__builtins__.list", Context())
-                if not sym:
-                    continue
-                node = sym.node
-                if not isinstance(node, TypeInfo):
-                    self.defer(node)
+                inst = self.named_type_or_none("builtins.list", [str_type])
+                if inst is None:
+                    assert not self.final_iteration, "Cannot find builtins.list to add __path__"
+                    self.defer()
                     return
-                typ = Instance(node, [str_type])
+                typ = inst
             elif name == "__annotations__":
-                sym = self.lookup_qualified("__builtins__.dict", Context(), suppress_errors=True)
-                if not sym:
-                    continue
-                node = sym.node
-                if not isinstance(node, TypeInfo):
-                    self.defer(node)
+                inst = self.named_type_or_none(
+                    "builtins.dict", [str_type, AnyType(TypeOfAny.special_form)]
+                )
+                if inst is None:
+                    assert (
+                        not self.final_iteration
+                    ), "Cannot find builtins.dict to add __annotations__"
+                    self.defer()
                     return
-                typ = Instance(node, [str_type, AnyType(TypeOfAny.special_form)])
+                typ = inst
             else:
                 assert t is not None, f"type should be specified for {name}"
                 typ = UnboundType(t)
diff --git a/mypy/semanal_namedtuple.py b/mypy/semanal_namedtuple.py
@@ -481,13 +481,9 @@ def build_namedtuple_typeinfo(
         strtype = self.api.named_type("builtins.str")
         implicit_any = AnyType(TypeOfAny.special_form)
         basetuple_type = self.api.named_type("builtins.tuple", [implicit_any])
-        dictype = self.api.named_type_or_none(
-            "builtins.dict", [strtype, implicit_any]
-        ) or self.api.named_type("builtins.object")
+        dictype = self.api.named_type("builtins.dict", [strtype, implicit_any])
         # Actual signature should return OrderedDict[str, Union[types]]
-        ordereddictype = self.api.named_type_or_none(
-            "builtins.dict", [strtype, implicit_any]
-        ) or self.api.named_type("builtins.object")
+        ordereddictype = self.api.named_type("builtins.dict", [strtype, implicit_any])
         fallback = self.api.named_type("builtins.tuple", [implicit_any])
         # Note: actual signature should accept an invariant version of Iterable[UnionType[types]].
         # but it can't be expressed. 'new' and 'len' should be callable types.
diff --git a/test-data/unit/check-dynamic-typing.test b/test-data/unit/check-dynamic-typing.test
@@ -147,6 +147,7 @@ class int: pass
 class type: pass
 class function: pass
 class str: pass
+class dict: pass
 
 [case testBinaryOperationsWithDynamicAsRightOperand]
 from typing import Any
@@ -219,6 +220,7 @@ class int: pass
 class type: pass
 class function: pass
 class str: pass
+class dict: pass
 
 [case testDynamicWithUnaryExpressions]
 from typing import Any
diff --git a/test-data/unit/check-generics.test b/test-data/unit/check-generics.test
@@ -1331,6 +1331,7 @@ class type: pass
 class tuple: pass
 class function: pass
 class str: pass
+class dict: pass
 
 [case testMultipleAssignmentWithIterable]
 from typing import Iterable, TypeVar
diff --git a/test-data/unit/check-incomplete-fixture.test b/test-data/unit/check-incomplete-fixture.test
@@ -12,14 +12,6 @@ import m
 m.x # E: "object" has no attribute "x"
 [file m.py]
 
-[case testDictMissingFromStubs]
-from typing import Dict
-def f(x: Dict[int]) -> None: pass
-[out]
-main:1: error: Module "typing" has no attribute "Dict"
-main:1: note: Maybe your test fixture does not define "builtins.dict"?
-main:1: note: Consider adding [builtins fixtures/dict.pyi] to your test description
-
 [case testSetMissingFromStubs]
 from typing import Set
 def f(x: Set[int]) -> None: pass
diff --git a/test-data/unit/check-tuples.test b/test-data/unit/check-tuples.test
@@ -774,6 +774,7 @@ class str: pass
 class bool: pass
 class type: pass
 class function: pass
+class dict: pass
 
 
 -- For loop over tuple
diff --git a/test-data/unit/cmdline.test b/test-data/unit/cmdline.test
@@ -1516,6 +1516,8 @@ a.py:2: note: By default the bodies of untyped functions are not checked, consid
 class object: pass
 class str(object): pass
 class int(object): pass
+class list: pass
+class dict: pass
 [file dir/stdlib/sys.pyi]
 [file dir/stdlib/types.pyi]
 [file dir/stdlib/typing.pyi]
diff --git a/test-data/unit/fine-grained.test b/test-data/unit/fine-grained.test
@@ -1809,8 +1809,8 @@ def f() -> Iterator[None]:
 [typing fixtures/typing-medium.pyi]
 [builtins fixtures/list.pyi]
 [triggered]
-2: <b>, __main__
-3: <b>, __main__, a
+2: <b>, <b[wildcard]>, __main__
+3: <b>, <b[wildcard]>, __main__, a
 [out]
 main:2: note: Revealed type is "contextlib.GeneratorContextManager[None]"
 ==
diff --git a/test-data/unit/fixtures/__init_subclass__.pyi b/test-data/unit/fixtures/__init_subclass__.pyi
@@ -11,3 +11,4 @@ class int: pass
 class bool: pass
 class str: pass
 class function: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/__new__.pyi b/test-data/unit/fixtures/__new__.pyi
@@ -16,3 +16,4 @@ class int: pass
 class bool: pass
 class str: pass
 class function: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/alias.pyi b/test-data/unit/fixtures/alias.pyi
@@ -12,3 +12,5 @@ class str: pass
 class function: pass
 
 bytes = str
+
+class dict: pass
diff --git a/test-data/unit/fixtures/any.pyi b/test-data/unit/fixtures/any.pyi
@@ -6,3 +6,5 @@ class int: pass
 class str: pass
 
 def any(i: Iterable[T]) -> bool: pass
+
+class dict: pass
diff --git a/test-data/unit/fixtures/attr.pyi b/test-data/unit/fixtures/attr.pyi
@@ -25,3 +25,5 @@ class complex:
 class str: pass
 class ellipsis: pass
 class tuple: pass
+class list: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/bool.pyi b/test-data/unit/fixtures/bool.pyi
@@ -17,3 +17,4 @@ class str: pass
 class ellipsis: pass
 class list(Generic[T]): pass
 class property: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/callable.pyi b/test-data/unit/fixtures/callable.pyi
@@ -28,3 +28,4 @@ class str:
     def __eq__(self, other: 'str') -> bool: pass
 class ellipsis: pass
 class list: ...
+class dict: pass
diff --git a/test-data/unit/fixtures/classmethod.pyi b/test-data/unit/fixtures/classmethod.pyi
@@ -26,3 +26,6 @@ class bool: pass
 class ellipsis: pass
 
 class tuple(typing.Generic[_T]): pass
+
+class list: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/complex.pyi b/test-data/unit/fixtures/complex.pyi
@@ -10,3 +10,4 @@ class int: pass
 class float: pass
 class complex: pass
 class str: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/complex_tuple.pyi b/test-data/unit/fixtures/complex_tuple.pyi
@@ -13,3 +13,4 @@ class float: pass
 class complex: pass
 class str: pass
 class ellipsis: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/divmod.pyi b/test-data/unit/fixtures/divmod.pyi
@@ -19,3 +19,5 @@ class ellipsis: pass
 
 _N = TypeVar('_N', int, float)
 def divmod(_x: _N, _y: _N) -> Tuple[_N, _N]: ...
+
+class dict: pass
diff --git a/test-data/unit/fixtures/exception.pyi b/test-data/unit/fixtures/exception.pyi
@@ -8,6 +8,8 @@ class object:
 class type: pass
 class tuple(Generic[T]):
     def __ge__(self, other: object) -> bool: ...
+class list: pass
+class dict: pass
 class function: pass
 class int: pass
 class str: pass
diff --git a/test-data/unit/fixtures/f_string.pyi b/test-data/unit/fixtures/f_string.pyi
@@ -34,3 +34,5 @@ class str:
     def format(self, *args) -> str: pass
     def join(self, l: List[str]) -> str: pass
 
+
+class dict: pass
diff --git a/test-data/unit/fixtures/fine_grained.pyi b/test-data/unit/fixtures/fine_grained.pyi
@@ -27,3 +27,4 @@ class tuple(Generic[T]): pass
 class function: pass
 class ellipsis: pass
 class list(Generic[T]): pass
+class dict: pass
diff --git a/test-data/unit/fixtures/float.pyi b/test-data/unit/fixtures/float.pyi
@@ -34,3 +34,5 @@ class float:
     def __int__(self) -> int: ...
     def __mul__(self, x: float) -> float: ...
     def __rmul__(self, x: float) -> float: ...
+
+class dict: pass
diff --git a/test-data/unit/fixtures/for.pyi b/test-data/unit/fixtures/for.pyi
@@ -18,3 +18,4 @@ class str: pass # for convenience
 
 class list(Iterable[t], Generic[t]):
     def __iter__(self) -> Iterator[t]: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/function.pyi b/test-data/unit/fixtures/function.pyi
@@ -5,3 +5,4 @@ class type: pass
 class function: pass
 class int: pass
 class str: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/isinstance.pyi b/test-data/unit/fixtures/isinstance.pyi
@@ -25,3 +25,5 @@ class str:
 class ellipsis: pass
 
 NotImplemented = cast(Any, None)
+
+class dict: pass
diff --git a/test-data/unit/fixtures/isinstance_python3_10.pyi b/test-data/unit/fixtures/isinstance_python3_10.pyi
@@ -27,3 +27,5 @@ class str:
 class ellipsis: pass
 
 NotImplemented = cast(Any, None)
+
+class dict: pass
diff --git a/test-data/unit/fixtures/list.pyi b/test-data/unit/fixtures/list.pyi
@@ -36,3 +36,5 @@ class str:
 class bool(int): pass
 
 property = object() # Dummy definition.
+
+class dict: pass
diff --git a/test-data/unit/fixtures/module_all.pyi b/test-data/unit/fixtures/module_all.pyi
@@ -16,3 +16,4 @@ class list(Generic[_T], Sequence[_T]):
     def __add__(self, rhs: Sequence[_T]) -> list[_T]: pass
 class tuple(Generic[_T]): pass
 class ellipsis: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/notimplemented.pyi b/test-data/unit/fixtures/notimplemented.pyi
@@ -11,3 +11,4 @@ class bool: pass
 class int: pass
 class str: pass
 NotImplemented = cast(Any, None)
+class dict: pass
diff --git a/test-data/unit/fixtures/object_hashable.pyi b/test-data/unit/fixtures/object_hashable.pyi
@@ -7,3 +7,4 @@ class float: ...
 class str: ...
 class ellipsis: ...
 class tuple: ...
+class dict: pass
diff --git a/test-data/unit/fixtures/ops.pyi b/test-data/unit/fixtures/ops.pyi
@@ -72,3 +72,5 @@ def __print(a1: object = None, a2: object = None, a3: object = None,
             a4: object = None) -> None: pass
 
 class ellipsis: pass
+
+class dict: pass
diff --git a/test-data/unit/fixtures/property.pyi b/test-data/unit/fixtures/property.pyi
@@ -13,6 +13,7 @@ class function: pass
 property = object()  # Dummy definition
 class classmethod: pass
 
+class list: pass
 class dict: pass
 class int: pass
 class str: pass
diff --git a/test-data/unit/fixtures/set.pyi b/test-data/unit/fixtures/set.pyi
@@ -25,3 +25,5 @@ class set(Iterable[T], Generic[T]):
     def add(self, x: T) -> None: pass
     def discard(self, x: T) -> None: pass
     def update(self, x: Set[T]) -> None: pass
+
+class dict: pass
diff --git a/test-data/unit/fixtures/slice.pyi b/test-data/unit/fixtures/slice.pyi
@@ -14,3 +14,4 @@ class str: pass
 
 class slice: pass
 class ellipsis: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/staticmethod.pyi b/test-data/unit/fixtures/staticmethod.pyi
@@ -18,3 +18,4 @@ class int:
 class str: pass
 class bytes: pass
 class ellipsis: pass
+class dict: pass
diff --git a/test-data/unit/fixtures/transform.pyi b/test-data/unit/fixtures/transform.pyi
@@ -28,3 +28,5 @@ def __print(a1=None, a2=None, a3=None, a4=None):
     # Do not use *args since this would require list and break many test
     # cases.
     pass
+
+class dict: pass
diff --git a/test-data/unit/fixtures/tuple-simple.pyi b/test-data/unit/fixtures/tuple-simple.pyi
@@ -18,3 +18,4 @@ class function: pass
 # We need int for indexing tuples.
 class int: pass
 class str: pass # For convenience
+class dict: pass
diff --git a/test-data/unit/fixtures/tuple.pyi b/test-data/unit/fixtures/tuple.pyi
@@ -51,3 +51,5 @@ def isinstance(x: object, t: type) -> bool: pass
 def sum(iterable: Iterable[T], start: Optional[T] = None) -> T: pass
 
 class BaseException: pass
+
+class dict: pass
diff --git a/test-data/unit/fixtures/union.pyi b/test-data/unit/fixtures/union.pyi
@@ -15,3 +15,4 @@ class tuple(Generic[T]): pass
 # We need int for indexing tuples.
 class int: pass
 class str: pass # For convenience
+class dict: pass
diff --git a/test-data/unit/lib-stub/builtins.pyi b/test-data/unit/lib-stub/builtins.pyi
@@ -21,8 +21,13 @@ class function:
     __name__: str
 class ellipsis: pass
 
-from typing import Generic, Sequence, TypeVar
+from typing import Generic, Iterator, Sequence, TypeVar
 _T = TypeVar('_T')
-class list(Generic[_T], Sequence[_T]): pass
+class list(Generic[_T], Sequence[_T]):
+    def __contains__(self, item: object) -> bool: pass
+    def __getitem__(self, key: int) -> _T: pass
+    def __iter__(self) -> Iterator[_T]: pass
+
+class dict: pass
 
 # Definition of None is implicit
diff --git a/test-data/unit/merge.test b/test-data/unit/merge.test
diff --git a/test-data/unit/typexport-basic.test b/test-data/unit/typexport-basic.test
