Hot-fix: do not share tags between ModelHubMixin siblings (#2394)

* Hot-fix: do not share tags between ModelHubMixin sibligs

* reference regression test

Author: Wauplin

src/huggingface_hub/hub_mixin.py

@@ -230,12 +230,21 @@ def __init_subclass__(
         tags.append("model_hub_mixin")
 
         # Initialize MixinInfo if not existent
-        if not hasattr(cls, "_hub_mixin_info"):
-            cls._hub_mixin_info = MixinInfo(
-                model_card_template=model_card_template,
-                model_card_data=ModelCardData(),
-            )
-        info = cls._hub_mixin_info
+        info = MixinInfo(model_card_template=model_card_template, model_card_data=ModelCardData())
+
+        # If parent class has a MixinInfo, inherit from it as a copy
+        if hasattr(cls, "_hub_mixin_info"):
+            # Inherit model card template from parent class if not explicitly set
+            if model_card_template == DEFAULT_MODEL_CARD:
+                info.model_card_template = cls._hub_mixin_info.model_card_template
+
+            # Inherit from parent model card data
+            info.model_card_data = ModelCardData(**cls._hub_mixin_info.model_card_data.to_dict())
+
+            # Inherit other info
+            info.docs_url = cls._hub_mixin_info.docs_url
+            info.repo_url = cls._hub_mixin_info.repo_url
+        cls._hub_mixin_info = info
 
         if languages is not None:
             warnings.warn(
@@ -269,6 +278,8 @@ def __init_subclass__(
             else:
                 info.model_card_data.tags = tags
 
+        info.model_card_data.tags = sorted(set(info.model_card_data.tags))
+
         # Handle encoders/decoders for args
         cls._hub_mixin_coders = coders or {}
         cls._hub_mixin_jsonable_custom_types = tuple(cls._hub_mixin_coders.keys())

tests/test_hub_mixin_pytorch.py

@@ -111,12 +111,20 @@ def __init__(self, config: Namespace):
             super().__init__()
             self.config = config
 
+    class DummyModelWithTag1(nn.Module, PyTorchModelHubMixin, tags=["tag1"]):
+        """Used to test tags not shared between sibling classes (only inheritance)."""
+
+    class DummyModelWithTag2(nn.Module, PyTorchModelHubMixin, tags=["tag2"]):
+        """Used to test tags not shared between sibling classes (only inheritance)."""
+
 else:
     DummyModel = None
     DummyModelWithModelCard = None
     DummyModelNoConfig = None
     DummyModelWithConfigAndKwargs = None
     DummyModelWithModelCardAndCustomKwargs = None
+    DummyModelWithTag1 = None
+    DummyModelWithTag2 = None
 
 
 @requires("torch")
@@ -451,3 +459,21 @@ def test_config_with_custom_coders(self):
         assert isinstance(reloaded.config, Namespace)
         assert reloaded.config.a == 1
         assert reloaded.config.b == 2
+
+    def test_inheritance_and_sibling_classes(self):
+        """
+        Test tags are not shared between sibling classes.
+
+        Regression test for #2394.
+        See https://github.com/huggingface/huggingface_hub/pull/2394.
+        """
+        assert DummyModelWithTag1._hub_mixin_info.model_card_data.tags == [
+            "model_hub_mixin",
+            "pytorch_model_hub_mixin",
+            "tag1",
+        ]
+        assert DummyModelWithTag2._hub_mixin_info.model_card_data.tags == [
+            "model_hub_mixin",
+            "pytorch_model_hub_mixin",
+            "tag2",
+        ]