Adds error for serializing metric using layer serialization.

PiperOrigin-RevId: 527991285

keras/layers/serialization.py

@@ -50,6 +50,7 @@
 from keras.layers.rnn import cell_wrappers
 from keras.layers.rnn import gru
 from keras.layers.rnn import lstm
+from keras.metrics import base_metric
 from keras.saving import serialization_lib
 from keras.saving.legacy import serialization as legacy_serialization
 from keras.saving.legacy.saved_model import json_utils
@@ -208,6 +209,13 @@ def serialize(layer, use_legacy_format=False):
  pprint(tf.keras.layers.serialize(model))
  # prints the configuration of the model, as a dict.
  """
+ if isinstance(layer, base_metric.Metric):
+ raise ValueError(
+ f"Cannot serialize {layer} since it is a metric. "
+ "Please use the `keras.metrics.serialize()` and "
+ "`keras.metrics.deserialize()` APIs to serialize "
+ "and deserialize metrics."
+ )
  if use_legacy_format:
  return legacy_serialization.serialize_keras_object(layer)
 

keras/layers/serialization_test.py

@@ -24,6 +24,7 @@
 from keras.layers.rnn import gru_v1
 from keras.layers.rnn import lstm
 from keras.layers.rnn import lstm_v1
+from keras.metrics import Mean
 from keras.testing_infra import test_combinations
 
 
@@ -191,6 +192,11 @@ def test_serialize_deserialize_gru(self, layer):
  self.assertIsInstance(new_layer, gru_v1.GRU)
  self.assertNotIsInstance(new_layer, gru.GRU)
 
+ def test_serialize_metric_throws_error(self):
+ metric = Mean()
+ with self.assertRaisesRegex(ValueError, "since it is a metric."):
+ _ = keras.layers.serialize(metric)
+
 
 if __name__ == "__main__":
  tf.test.main()