Handle fussy typing._type_check (#2)

alexmojaki · Dec 16, 2023 · 1b05f64 · 1b05f64
1 parent 5bed613
commit 1b05f64
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/eval_type_backport/eval_type_backport.py b/eval_type_backport/eval_type_backport.py
@@ -131,7 +131,13 @@ def visit_BinOp(self, node) -> ast.BinOp | ast.Subscript:
 
         def visit_Subscript(self, node):
             value_node = self.visit(node.value)
-            value_val = self.eval_type(value_node)
+            try:
+                value_val = self.eval_type(value_node)
+            except TypeError:
+                # Likely typing._type_check complaining that the result isn't a type,
+                # e.g. that it's a plain `Literal`.
+                # Either way, this probably isn't one of the new generic types that needs replacing.
+                return self.generic_visit(node)
             if value_val not in new_generic_types:
                 return self.generic_visit(node)
             slice_node = self.visit(node.slice)

diff --git a/tests/test_eval_type_backport.py b/tests/test_eval_type_backport.py
@@ -92,6 +92,13 @@ def test_eval_type_backport():
             ]
         ],
     )
+    if hasattr(t, 'Literal'):
+        check_eval('t.Literal[1]', t.Literal[1])
+        check_eval('t.Literal[1] | t.Literal[2]', t.Union[t.Literal[1], t.Literal[2]])
+        check_eval(
+            't.List[t.Literal[1] | t.Literal[2]]',
+            t.List[t.Union[t.Literal[1], t.Literal[2]]],
+        )
 
 
 def test_other_type_error():