Add support for BinOr typing union syntax

Author: UnknownPlatypus

pyupgrade/_plugins/typing_classes.py

@@ -46,6 +46,8 @@ def _unparse(node: ast.expr) -> str:
         return '[{}]'.format(', '.join(_unparse(elt) for elt in node.elts))
     elif isinstance(node, ast.NameConstant):
         return repr(node.value)
+    elif isinstance(node, ast.BinOp) and isinstance(node.op, ast.BitOr):
+        return f'{_unparse(node.left)} | {_unparse(node.right)}'
     else:
         raise NotImplementedError(ast.dump(node))
 

tests/features/typing_classes_test.py

@@ -210,6 +210,16 @@ def test_typing_named_tuple_noop(s):
 
             id='preserves comments without alignment',
         ),
+        pytest.param(
+            'from typing import NamedTuple\n'
+            'Foo = NamedTuple("Foo", [("union", str | None)])',
+
+            'from typing import NamedTuple\n'
+            'class Foo(NamedTuple):\n'
+            '    union: str | None',
+
+            id='BitOr unparse error',
+        ),
     ),
 )
 def test_fix_typing_named_tuple(s, expected):
@@ -393,6 +403,16 @@ def test_typing_typed_dict_noop(s):
 
             id='right after a dedent',
         ),
+        pytest.param(
+            'from typing import TypedDict\n'
+            'Foo = TypedDict("Foo", {"union": str | int | None})',
+
+            'from typing import TypedDict\n'
+            'class Foo(TypedDict):\n'
+            '    union: str | int | None',
+
+            id='BitOr unparse error',
+        ),
     ),
 )
 def test_typing_typed_dict(s, expected):