Fix ignore_mismatched_sizes (#14085)

* Fix

* Style

* Name

* Fix tests

* Style

* Remove embed sizes checking

* Disable some tests

* Fix

* Apply suggestion

tests/test_modeling_tf_common.py

@@ -59,6 +59,7 @@ if is_tf_available():
         TF_MODEL_FOR_SEQUENCE_CLASSIFICATION_MAPPING,
         TF_MODEL_FOR_TOKEN_CLASSIFICATION_MAPPING,
         BertConfig,
+        TFAutoModel,
         TFAutoModelForSequenceClassification,
         TFBertModel,
         TFSharedEmbeddings,
@@ -104,6 +105,7 @@ class TFModelTesterMixin:
     model_tester = None
     all_model_classes = ()
     all_generative_model_classes = ()
+    test_mismatched_shapes = True
     test_resize_embeddings = True
     test_head_masking = True
     is_encoder_decoder = False
@@ -1312,6 +1314,8 @@ class TFModelTesterMixin:
                 self.assertEqual(sum([tf.reduce_sum(w).numpy() for w in attn_weights]), 0.0)
 
     def test_load_with_mismatched_shapes(self):
+        if not self.test_mismatched_shapes:
+            return
         config, inputs_dict = self.model_tester.prepare_config_and_inputs_for_common()
 
         for model_class in self.all_model_classes:
@@ -1328,6 +1332,8 @@ class TFModelTesterMixin:
                     # Fails when we don't set ignore_mismatched_sizes=True
                     with self.assertRaises(ValueError):
                         new_model = TFAutoModelForSequenceClassification.from_pretrained(tmp_dir, num_labels=42)
+                    with self.assertRaises(ValueError):
+                        new_model_without_prefix = TFAutoModel.from_pretrained(tmp_dir, vocab_size=10)
 
                     logger = logging.get_logger("transformers.modeling_tf_utils")
                     with CaptureLogger(logger) as cl:
@@ -1339,6 +1345,20 @@ class TFModelTesterMixin:
                     logits = new_model(**inputs).logits
                     self.assertEqual(logits.shape[1], 42)
 
+                    with CaptureLogger(logger) as cl:
+                        new_model_without_prefix = TFAutoModel.from_pretrained(
+                            tmp_dir, vocab_size=10, ignore_mismatched_sizes=True
+                        )
+                    self.assertIn("the shapes did not match", cl.out)
+
+                    # Although Tf models always have a prefix pointing to `MainLayer`,
+                    # we still add this "without prefix" test to keep a consistency between tf and pt tests.
+                    input_ids = ids_tensor((2, 8), 10)
+                    if self.is_encoder_decoder:
+                        new_model_without_prefix(input_ids, decoder_input_ids=input_ids)
+                    else:
+                        new_model_without_prefix(input_ids)
+
     def _generate_random_bad_tokens(self, num_bad_tokens, model):
         # special tokens cannot be bad tokens
         special_tokens = []