Fix Literal parse error in RemoveImportsVisitor (#1130)

libcst/codemod/visitors/_gather_string_annotation_names.py

@@ -44,6 +44,11 @@ def visit_Annotation(self, node: cst.Annotation) -> bool:
     def leave_Annotation(self, original_node: cst.Annotation) -> None:
         self._annotation_stack.pop()
 
+    def visit_Subscript(self, node: cst.Subscript) -> bool:
+        qnames = self.get_metadata(QualifiedNameProvider, node)
+        # A Literal["foo"] should not be interpreted as a use of the symbol "foo".
+        return not any(qn.name == "typing.Literal" for qn in qnames)
+
     def visit_Call(self, node: cst.Call) -> bool:
         qnames = self.get_metadata(QualifiedNameProvider, node)
         if any(qn.name in self._typing_functions for qn in qnames):
@@ -71,7 +76,11 @@ def handle_any_string(
         value = node.evaluated_value
         if value is None:
             return
-        mod = cst.parse_module(value)
+        try:
+            mod = cst.parse_module(value)
+        except cst.ParserSyntaxError:
+            # Not all strings inside a type annotation are meant to be valid Python code.
+            return
         extracted_nodes = m.extractall(
             mod,
             m.Name(

libcst/codemod/visitors/tests/test_gather_string_annotation_names.py

@@ -80,3 +80,14 @@ def test_dotted_names(self) -> None:
             visitor.names,
             {"api", "api.http_exceptions", "api.http_exceptions.HttpException"},
         )
+
+    def test_literals(self) -> None:
+        visitor = self.gather_names(
+            """
+            from typing import Literal
+            a: Literal["in"]
+            b: list[Literal["1x"]]
+            c: Literal["Any"]
+            """
+        )
+        self.assertEqual(visitor.names, set())