Allow inverting --local-partial-types (#18377)

Also add it to a bunch of test cases where it is needed

Author: hauntsaninja

mypy/main.py

@@ -1185,7 +1185,7 @@ def add_invertible_flag(
     parser.add_argument("--test-env", action="store_true", help=argparse.SUPPRESS)
     # --local-partial-types disallows partial types spanning module top level and a function
     # (implicitly defined in fine-grained incremental mode)
-    parser.add_argument("--local-partial-types", action="store_true", help=argparse.SUPPRESS)
+    add_invertible_flag("--local-partial-types", default=False, help=argparse.SUPPRESS)
     # --logical-deps adds some more dependencies that are not semantically needed, but
     # may be helpful to determine relative importance of classes and functions for overall
     # type precision in a code base. It also _removes_ some deps, so this flag should be never

test-data/unit/check-bound.test

@@ -46,7 +46,7 @@ z = G(B())
 
 
 [case testBoundVoid]
-# flags: --no-strict-optional
+# flags: --no-strict-optional --no-local-partial-types
 from typing import TypeVar, Generic
 T = TypeVar('T', bound=int)
 class C(Generic[T]):
@@ -75,7 +75,7 @@ z: C
 
 
 [case testBoundHigherOrderWithVoid]
-# flags: --no-strict-optional
+# flags: --no-strict-optional --no-local-partial-types
 from typing import TypeVar, Callable
 class A: pass
 T = TypeVar('T', bound=A)

test-data/unit/check-classes.test

@@ -113,7 +113,7 @@ A().f = None  # E: Cannot assign to a method \
 from typing import Protocol
 
 class Base:
-    __hash__ = None
+    __hash__: None = None
 
 class Derived(Base):
     def __hash__(self) -> int:  # E: Signature of "__hash__" incompatible with supertype "Base" \

test-data/unit/check-columns.test

@@ -210,6 +210,7 @@ y: Dict[int, int] = {
 [builtins fixtures/dict.pyi]
 
 [case testColumnCannotDetermineType]
+# flags: --no-local-partial-types
 (x)  # E:2: Cannot determine type of "x"  # E:2: Name "x" is used before definition
 x = None
 

test-data/unit/check-custom-plugin.test

@@ -1007,7 +1007,7 @@ reveal_type(Cls.attr) # N: Revealed type is "builtins.int"
 plugins=<ROOT>/test-data/unit/plugins/class_attr_hook.py
 
 [case testClassAttrPluginPartialType]
-# flags: --config-file tmp/mypy.ini
+# flags: --config-file tmp/mypy.ini --no-local-partial-types
 
 class Cls:
     attr = None

test-data/unit/check-errorcodes.test

@@ -837,7 +837,7 @@ Foo = TypedDict("Bar", {})  # E: First argument "Bar" to TypedDict() does not ma
 [builtins fixtures/dict.pyi]
 
 [case testTruthyBool]
-# flags: --enable-error-code truthy-bool
+# flags: --enable-error-code truthy-bool --no-local-partial-types
 from typing import List, Union, Any
 
 class Foo:

test-data/unit/check-incremental.test

@@ -6317,6 +6317,7 @@ class C: ...
 [out3]
 
 [case testNoCrashOnPartialLambdaInference]
+# flags: --no-local-partial-types
 import m
 [file m.py]
 from typing import TypeVar, Callable

test-data/unit/check-inference.test

@@ -1728,12 +1728,14 @@ b[{}] = 1
 [builtins fixtures/dict.pyi]
 
 [case testInferDictInitializedToEmptyAndUpdatedFromMethod]
+# flags: --no-local-partial-types
 map = {}
 def add() -> None:
     map[1] = 2
 [builtins fixtures/dict.pyi]
 
 [case testInferDictInitializedToEmptyAndUpdatedFromMethodUnannotated]
+# flags: --no-local-partial-types
 map = {}
 def add():
     map[1] = 2
@@ -1921,6 +1923,7 @@ reveal_type(C().a)  # N: Revealed type is "builtins.dict[Any, Any]"
 [builtins fixtures/dict.pyi]
 
 [case testInferAttributeInitializedToNoneAndAssignedClassBody]
+# flags: --no-local-partial-types
 class C:
     a = None
     def __init__(self) -> None:
@@ -2069,6 +2072,7 @@ x = 1
 [out]
 
 [case testPartiallyInitializedVariableDoesNotEscapeScope2]
+# flags: --no-local-partial-types
 x = None
 def f() -> None:
     x = None
@@ -2114,36 +2118,32 @@ class C:
 -- ------------------------
 
 [case testPartialTypeErrorSpecialCase1]
+# flags: --no-local-partial-types
 # This used to crash.
 class A:
     x = None
     def f(self) -> None:
-        for a in self.x:
+        for a in self.x:  # E: "None" has no attribute "__iter__" (not iterable)
             pass
 [builtins fixtures/for.pyi]
-[out]
-main:5: error: "None" has no attribute "__iter__" (not iterable)
 
 [case testPartialTypeErrorSpecialCase2]
 # This used to crash.
 class A:
-    x = []
+    x = []  # E: Need type annotation for "x" (hint: "x: List[<type>] = ...")
     def f(self) -> None:
         for a in self.x:
             pass
 [builtins fixtures/for.pyi]
-[out]
-main:3: error: Need type annotation for "x" (hint: "x: List[<type>] = ...")
 
 [case testPartialTypeErrorSpecialCase3]
+# flags: --no-local-partial-types
 class A:
     x = None
     def f(self) -> None:
-        for a in A.x:
+        for a in A.x:  # E: "None" has no attribute "__iter__" (not iterable)
             pass
 [builtins fixtures/for.pyi]
-[out]
-main:4: error: "None" has no attribute "__iter__" (not iterable)
 
 [case testPartialTypeErrorSpecialCase4]
 # This used to crash.
@@ -2492,6 +2492,7 @@ main:4: error: Unsupported target for indexed assignment ("Type[C[T]]")
 main:4: error: Invalid type: try using Literal[0] instead?
 
 [case testNoCrashOnPartialMember]
+# flags: --no-local-partial-types
 class C:
     x = None
     def __init__(self) -> None:
@@ -2512,6 +2513,7 @@ reveal_type(x) # N: Revealed type is "builtins.str"
 [out]
 
 [case testNoCrashOnPartialVariable2]
+# flags: --no-local-partial-types
 from typing import Tuple, TypeVar
 T = TypeVar('T', bound=str)
 

test-data/unit/check-narrowing.test

@@ -2354,6 +2354,7 @@ def fn_while(arg: T) -> None:
 [builtins fixtures/primitives.pyi]
 
 [case testRefinePartialTypeWithinLoop]
+# flags: --no-local-partial-types
 
 x = None
 for _ in range(2):

test-data/unit/check-optional.test

@@ -321,10 +321,13 @@ def f() -> Generator[None, None, None]:
 [out]
 
 [case testNoneAndStringIsNone]
-a = None
+a: None = None
 b = "foo"
 reveal_type(a and b)  # N: Revealed type is "None"
 
+c = None
+reveal_type(c and b)  # N: Revealed type is "None"
+
 [case testNoneMatchesObjectInOverload]
 import a
 a.f(None)
@@ -581,7 +584,7 @@ x is not None and x + '42'  # E: Unsupported operand types for + ("int" and "str
 [case testInvalidBooleanBranchIgnored]
 from typing import Optional
 
-x = None
+x: None = None
 x is not None and x + 42
 [builtins fixtures/isinstance.pyi]