Fix incremental crash bug caused by NewType in functions (#8607)

Author: msullivan

mypy/semanal_newtype.py

@@ -42,23 +42,27 @@ def process_newtype_declaration(self, s: AssignmentStmt) -> bool:
         The logic in this function mostly copies the logic for visit_class_def()
         with a single (non-Generic) base.
         """
-        name, call = self.analyze_newtype_declaration(s)
-        if name is None or call is None:
+        var_name, call = self.analyze_newtype_declaration(s)
+        if var_name is None or call is None:
             return False
+        name = var_name
         # OK, now we know this is a NewType. But the base type may be not ready yet,
         # add placeholder as we do for ClassDef.
 
+        if self.api.is_func_scope():
+            name += '@' + str(s.line)
         fullname = self.api.qualified_name(name)
+
         if (not call.analyzed or
                 isinstance(call.analyzed, NewTypeExpr) and not call.analyzed.info):
             # Start from labeling this as a future class, as we do for normal ClassDefs.
             placeholder = PlaceholderNode(fullname, s, s.line, becomes_typeinfo=True)
-            self.api.add_symbol(name, placeholder, s, can_defer=False)
+            self.api.add_symbol(var_name, placeholder, s, can_defer=False)
 
-        old_type, should_defer = self.check_newtype_args(name, call, s)
+        old_type, should_defer = self.check_newtype_args(var_name, call, s)
         old_type = get_proper_type(old_type)
         if not call.analyzed:
-            call.analyzed = NewTypeExpr(name, old_type, line=call.line, column=call.column)
+            call.analyzed = NewTypeExpr(var_name, old_type, line=call.line, column=call.column)
         if old_type is None:
             if should_defer:
                 # Base type is not ready.
@@ -98,7 +102,9 @@ def process_newtype_declaration(self, s: AssignmentStmt) -> bool:
             call.analyzed.info = newtype_class_info
         else:
             call.analyzed.info.bases = newtype_class_info.bases
-        self.api.add_symbol(name, call.analyzed.info, s)
+        self.api.add_symbol(var_name, call.analyzed.info, s)
+        if self.api.is_func_scope():
+            self.api.add_symbol_skip_local(name, call.analyzed.info)
         newtype_class_info.line = s.line
         return True
 
@@ -191,7 +197,7 @@ def build_newtype_typeinfo(self, name: str, old_type: Type, base_type: Instance)
             name=name)
         init_func = FuncDef('__init__', args, Block([]), typ=signature)
         init_func.info = info
-        init_func._fullname = self.api.qualified_name(name) + '.__init__'
+        init_func._fullname = info.fullname + '.__init__'
         info.names['__init__'] = SymbolTableNode(MDEF, init_func)
 
         return info

mypy/semanal_shared.py

@@ -162,6 +162,10 @@ def qualified_name(self, n: str) -> str:
     def is_typeshed_stub_file(self) -> bool:
         raise NotImplementedError
 
+    @abstractmethod
+    def is_func_scope(self) -> bool:
+        raise NotImplementedError
+
 
 def create_indirect_imported_name(file_node: MypyFile,
                                   module: str,

test-data/unit/check-incremental.test

@@ -1896,6 +1896,28 @@ main:1: error: Module 'tdcrash' has no attribute 'nope'
 [out2]
 main:1: error: Module 'tdcrash' has no attribute 'nope'
 
+[case testIncrementalNewTypeInMethod]
+from ntcrash import nope
+[file ntcrash.py]
+from mypy_extensions import TypedDict
+from typing import NewType, NamedTuple
+class C:
+    def f(self) -> None:
+        X = NewType('X', int)
+        A = TypedDict('A', {'x': X, 'y': int})
+        B = NamedTuple('B', [('x', X)])
+
+def f() -> None:
+    X = NewType('X', int)
+    A = TypedDict('A', {'x': X, 'y': int})
+    B = NamedTuple('B', [('x', X)])
+
+[builtins fixtures/dict.pyi]
+[out1]
+main:1: error: Module 'ntcrash' has no attribute 'nope'
+[out2]
+main:1: error: Module 'ntcrash' has no attribute 'nope'
+
 [case testIncrementalInnerClassAttrInMethod]
 import crash
 nonexisting
@@ -2274,6 +2296,7 @@ tmp/c.py:1: error: Module 'd' has no attribute 'x'
 [out]
 [out2]
 mypy: can't read file 'tmp/nonexistent.py': No such file or directory
+-- '
 
 [case testSerializeAbstractPropertyIncremental]
 from abc import abstractmethod
@@ -2484,7 +2507,7 @@ A = Dict[str, int]
 [out]
 
 -- Some crazy self-referential named tuples, types dicts, and aliases
--- to be sure that everything can be _serialized_ (i.e. ForwardRef's are removed).
+-- to be sure that everything can be _serialized_ (i.e. ForwardRefs are removed).
 -- For this reason errors are silenced (tests with # type: ignore have equivalents in other files)
 
 [case testForwardTypeAliasInBase1]

test-data/unit/check-newtype.test

@@ -194,7 +194,7 @@ def func() -> None:
     A = NewType('A', str)
     B = NewType('B', str)
 
-    a = A(3)  # E: Argument 1 to "A" has incompatible type "int"; expected "str"
+    a = A(3)  # E: Argument 1 to "A@6" has incompatible type "int"; expected "str"
     a = A('xyz')
     b = B('xyz')