[JIT] Disallow plain List type annotation without arg (#44584)

Meghan Lele · facebook-github-bot · commit 78b806ab4af9 · 2020-09-16T15:08:04.000-07:00
Summary: Pull Request resolved: #44584 **Summary** This commit extends the work done in #38130 and disallows plain Python3-style `List` type annotations. **Test Plan** This commit extends `TestList.test_no_element_type_annotation` to the Python3-style type annotation. Test Plan: Imported from OSS Reviewed By: gmagogsfm Differential Revision: D23721514 Pulled By: SplitInfinity fbshipit-source-id: 48957868286f44ab6d5bf5e1bf97f0a4ebf955df
diff --git a/test/jit/test_list_dict.py b/test/jit/test_list_dict.py
@@ -1132,17 +1132,28 @@ def to_list_float_1D(x):
             5, dtype=torch.double).cuda(),))
 
     def test_no_element_type_annotation(self):
-        def fn(x):
+        def fn_with_comment(x):
             # type: (torch.Tensor) -> List
             a: List = x.tolist()
             return a
 
-        with self.assertRaisesRegex(RuntimeError, r"Unknown type name"):
+        def annotated_fn(x: torch.Tensor) -> List:
+            a: List = x.tolist()
+            return a
+
+        with self.assertRaisesRegex(RuntimeError, r"Attempted to use List without a contained type"):
             cu = torch.jit.CompilationUnit()
-            cu.define(dedent(inspect.getsource(fn)))
+            cu.define(dedent(inspect.getsource(fn_with_comment)))
+
+        with self.assertRaisesRegex(RuntimeError, r"Attempted to use List without a contained type"):
+            cu = torch.jit.CompilationUnit()
+            cu.define(dedent(inspect.getsource(annotated_fn)))
+
+        with self.assertRaisesRegex(RuntimeError, r"Attempted to use List without a contained type"):
+            torch.jit.script(fn_with_comment)
 
-        with self.assertRaisesRegex(RuntimeError, r"Unknown type name"):
-            torch.jit.script(fn)
+        with self.assertRaisesRegex(RuntimeError, r"Attempted to use List without a contained type"):
+            torch.jit.script(annotated_fn)
 
 
 class TestDict(JitTestCase):
diff --git a/torch/_jit_internal.py b/torch/_jit_internal.py
@@ -635,6 +635,13 @@ def is_tuple(ann):
             getattr(ann, '__origin__', None) is tuple)
 
 def is_list(ann):
+    if ann is List:
+        raise RuntimeError(
+            "Attempted to use List without a "
+            "contained type. Please add a contained type, e.g. "
+            "List[int]"
+        )
+
     if not hasattr(ann, '__module__'):
         return False
     return ann.__module__ == 'typing' and \
