add config tests

src/peft/utils/config.py

@@ -38,10 +38,15 @@ class TaskType(str, enum.Enum):
 
 @dataclass
 class PeftConfigMixin(object):
+    peft_type: Optional[PeftType] = field(default=None, metadata={"help": "The type of PEFT model."})
+
     @property
     def __dict__(self):
         return asdict(self)
 
+    def to_dict(self):
+        return self.__dict__
+
     def save_pretrained(self, save_directory):
         if os.path.isfile(save_directory):
             raise AssertionError(f"Provided path ({save_directory}) should be a directory, not a file")

tests/test_config.py

@@ -0,0 +1,79 @@
+import unittest
+import tempfile
+import os
+
+from peft import LoraConfig, PromptEncoderConfig, PrefixTuningConfig, PromptTuningConfig
+
+class PeftConfigMixin:
+    all_config_classes = (
+        LoraConfig,
+        PromptEncoderConfig,
+        PrefixTuningConfig,
+        PromptTuningConfig,
+    )
+
+
+class PeftConfigTester(unittest.TestCase, PeftConfigMixin):
+    def test_methods(self):
+        r"""
+        Test if all configs have the expected methods. Here we test
+        - to_dict
+        - save_pretrained
+        - from_pretrained
+        - from_json_file
+        """
+        # test if all configs have the expected methods
+        for config_class in self.all_config_classes:
+            config = config_class()
+            self.assertTrue(hasattr(config, "to_dict"))
+            self.assertTrue(hasattr(config, "save_pretrained"))
+            self.assertTrue(hasattr(config, "from_pretrained"))
+            self.assertTrue(hasattr(config, "from_json_file"))
+
+
+    def test_save_pretrained(self):
+        r"""
+        Test if the config is correctly saved and loaded using 
+        - save_pretrained
+        """
+        for config_class in self.all_config_classes:
+            config = config_class()
+            with tempfile.TemporaryDirectory() as tmp_dirname:
+                config.save_pretrained(tmp_dirname)
+
+                config_from_pretrained = config_class.from_pretrained(tmp_dirname)
+                self.assertEqual(config.to_dict(), config_from_pretrained.to_dict())
+    
+    def test_from_json_file(self):
+        for config_class in self.all_config_classes:
+            config = config_class()
+            with tempfile.TemporaryDirectory() as tmp_dirname:
+                config.save_pretrained(tmp_dirname)
+
+                config_from_json = config_class.from_json_file(os.path.join(tmp_dirname, "adapter_config.json"))
+                self.assertEqual(config.to_dict(), config_from_json)
+    
+
+    def test_to_dict(self):
+        r"""
+        Test if the config can be correctly converted to a dict using:
+        - to_dict 
+        - __dict__
+        """
+        for config_class in self.all_config_classes:
+            config = config_class()
+            self.assertEqual(config.to_dict(), config.__dict__)
+            self.assertTrue(isinstance(config.to_dict(), dict))
+
+    
+    def test_set_attributes(self):
+        # manually set attributes and check if they are correctly written
+        for config_class in self.all_config_classes:
+            config = config_class(peft_type="test")
+
+            # save pretrained
+            with tempfile.TemporaryDirectory() as tmp_dirname:
+                config.save_pretrained(tmp_dirname)
+
+                config_from_pretrained = config_class.from_pretrained(tmp_dirname)
+                self.assertEqual(config.to_dict(), config_from_pretrained.to_dict())