Update based on feedback

python · JukkaL · Feb 20, 2018 · Jan 22, 2018 · Feb 7, 2018 · Feb 7, 2018
commit 3f3e4f06cd3cce12032cb6c8e62de7a65afc12f1
diff --git a/mypy/checker.py b/mypy/checker.py
@@ -107,9 +107,11 @@
         ('is_upper_bound', bool),  # False => precise type
     ])
 
-# Keeps track of partial types in a single scope
-PartialTypeScope = NamedTuple('PartialTypeMap', [('map', Dict[Var, Context]),
-                                                 ('is_function', bool)])
+# Keeps track of partial types in a single scope. In fine-grained incremental
+# mode partial types initially defined at the top level cannot be completed in
+# a function, and we use the 'is_function' attribute to enforce this.
+PartialTypeScope = NamedTuple('PartialTypeScope', [('map', Dict[Var, Context]),
+                                                   ('is_function', bool)])
 
 
 class TypeChecker(NodeVisitor[None], CheckerPluginInterface):

diff --git a/test-data/unit/check-inference.test b/test-data/unit/check-inference.test
@@ -2213,6 +2213,23 @@ class B(A):
 class C(B):
     y = None
 
+[case testLocalPartialTypesInMultipleMroItems]
+# flags: --local-partial-types --strict-optional
+from typing import Optional
+
+class A:
+    x: Optional[str]
+
+class B(A):
+    x = None
+
+class C(B):
+    x = None
+
+# TODO: Inferring None below is unsafe (https://github.com/python/mypy/issues/3208)
+reveal_type(B.x)  # E: Revealed type is 'builtins.None'
+reveal_type(C.x)  # E: Revealed type is 'builtins.None'
+
 [case testLocalPartialTypesWithInheritance2-skip]
 # flags: --local-partial-types
 # This is failing because of https://github.com/python/mypy/issues/4552

diff --git a/test-data/unit/fine-grained.test b/test-data/unit/fine-grained.test
@@ -1844,3 +1844,20 @@ def f() -> None:
 [out]
 ==
 a.py:1: error: Need type annotation for 'y'
+
+[case testNonePartialType4]
+import a
+[file a.py]
+y = None
+def f() -> None:
+    global y
+    y = ''
+[file a.py.2]
+from typing import Optional
+y: Optional[str] = None
+def f() -> None:
+    global y
+    y = ''
+[out]
+a.py:1: error: Need type annotation for 'y'
+==