Add missing to_type_hint to WindowedValueCoder (#33403)

* Add missing to_type_hint to WindowedValueCoder * Add type ignore to make mypy happy.
apache · Dec 17, 2024 · 470d7d6 · 470d7d6
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commit 470d7d6
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diff --git a/sdks/python/apache_beam/coders/coders.py b/sdks/python/apache_beam/coders/coders.py
@@ -1446,6 +1446,9 @@ def from_type_hint(cls, typehint, registry):
     # pickle coders.
     return cls(registry.get_coder(typehint.inner_type))
 
+  def to_type_hint(self):
+    return typehints.WindowedValue[self.wrapped_value_coder.to_type_hint()]
+
 
 Coder.register_structured_urn(
     common_urns.coders.WINDOWED_VALUE.urn, WindowedValueCoder)

diff --git a/sdks/python/apache_beam/coders/coders_test.py b/sdks/python/apache_beam/coders/coders_test.py
@@ -258,6 +258,12 @@ def test_numpy_int(self):
         _ = indata | "CombinePerKey" >> beam.CombinePerKey(sum)
 
 
+class WindowedValueCoderTest(unittest.TestCase):
+  def test_to_type_hint(self):
+    coder = coders.WindowedValueCoder(coders.VarIntCoder())
+    self.assertEqual(coder.to_type_hint(), typehints.WindowedValue[int])  # type: ignore[misc]
+
+
 if __name__ == '__main__':
   logging.getLogger().setLevel(logging.INFO)
   unittest.main()