add test for sharded checkpoint

Author: SunMarc

src/diffusers/models/modeling_utils.py

@@ -825,7 +825,7 @@ def from_pretrained(cls, pretrained_model_name_or_path: Optional[Union[str, os.P
                     dduf_entries=dduf_entries,
                 )
                 # TODO: https://github.com/huggingface/diffusers/issues/10013
-                if hf_quantizer is not None:
+                if hf_quantizer is not None or dduf_entries:
                     model_file = _merge_sharded_checkpoints(
                         sharded_ckpt_cached_folder, sharded_metadata, dduf_entries=dduf_entries
                     )

tests/pipelines/test_pipelines.py

@@ -1875,6 +1875,18 @@ def test_wrong_model(self):
         assert "is of type" in str(error_context.exception)
         assert "but should be" in str(error_context.exception)
 
+    @require_hf_hub_version_greater("0.26.5")
+    @require_transformers_version_greater("4.47.1")
+    def test_dduf_load_sharded_checkpoint_diffusion_model(self):
+        with tempfile.TemporaryDirectory() as tmpdir:
+            pipe = DiffusionPipeline.from_pretrained(
+                "hf-internal-testing/tiny-flux-dev-pipe-sharded-checkpoint-DDUF",
+                dduf_file="tiny-flux-dev-pipe-sharded-checkpoint.dduf",
+                cache_dir=tmpdir,
+            ).to(torch_device)
+
+            pipe(prompt="dog", num_inference_steps=5, generator=torch.manual_seed(0), output_type="np").images
+
 
 @slow
 @require_torch_gpu