Adapt test and underlying behavior

Author: sgugger

src/transformers/models/auto/configuration_auto.py

@@ -703,9 +703,10 @@ def from_pretrained(cls, pretrained_model_name_or_path, **kwargs):
             return config_class.from_dict(config_dict, **kwargs)
         else:
             # Fallback: use pattern matching on the string.
-            for pattern, config_class in CONFIG_MAPPING.items():
+            # We go from longer names to shorter names to catch roberta before bert (for instance)
+            for pattern in sorted(CONFIG_MAPPING.keys(), key=len, reverse=True):
                 if pattern in str(pretrained_model_name_or_path):
-                    return config_class.from_dict(config_dict, **kwargs)
+                    return CONFIG_MAPPING[pattern].from_dict(config_dict, **kwargs)
 
         raise ValueError(
             f"Unrecognized model in {pretrained_model_name_or_path}. "

tests/models/auto/test_configuration_auto.py

@@ -14,6 +14,8 @@
 # limitations under the License.
 
 import importlib
+import json
+import os
 import sys
 import tempfile
 import unittest
@@ -56,14 +58,14 @@ def test_config_for_model_str(self):
         self.assertIsInstance(config, RobertaConfig)
 
     def test_pattern_matching_fallback(self):
-        """
-        In cases where config.json doesn't include a model_type,
-        perform a few safety checks on the config mapping's order.
-        """
-        # no key string should be included in a later key string (typical failure case)
-        keys = list(CONFIG_MAPPING.keys())
-        for i, key in enumerate(keys):
-            self.assertFalse(any(key in later_key for later_key in keys[i + 1 :]))
+        with tempfile.TemporaryDirectory() as tmp_dir:
+            # This model name contains bert and roberta, but roberta ends up being picked.
+            folder = os.path.join(tmp_dir, "fake-roberta")
+            os.makedirs(folder, exist_ok=True)
+            with open(os.path.join(folder, "config.json"), "w") as f:
+                f.write(json.dumps({}))
+            config = AutoConfig.from_pretrained(folder)
+            self.assertEqual(type(config), RobertaConfig)
 
     def test_new_config_registration(self):
         try: