[Tests] fix: lumina2 lora fuse_nan test (#10911)

fix: lumina2 lora fuse_nan test

tests/lora/test_lora_layers_lumina2.py

@@ -15,6 +15,8 @@
 import sys
 import unittest
 
+import numpy as np
+import pytest
 import torch
 from transformers import AutoTokenizer, GemmaForCausalLM
 
@@ -24,12 +26,12 @@ from diffusers import (
     Lumina2Text2ImgPipeline,
     Lumina2Transformer2DModel,
 )
-from diffusers.utils.testing_utils import floats_tensor, require_peft_backend
+from diffusers.utils.testing_utils import floats_tensor, is_torch_version, require_peft_backend, skip_mps, torch_device
 
 
 sys.path.append(".")
 
-from utils import PeftLoraLoaderMixinTests  # noqa: E402
+from utils import PeftLoraLoaderMixinTests, check_if_lora_correctly_set  # noqa: E402
 
 
 @require_peft_backend
@@ -130,3 +132,41 @@ class Lumina2LoRATests(unittest.TestCase, PeftLoraLoaderMixinTests):
     @unittest.skip("Text encoder LoRA is not supported in Lumina2.")
     def test_simple_inference_with_text_lora_save_load(self):
         pass
+
+    @skip_mps
+    @pytest.mark.xfail(
+        condition=torch.device(torch_device).type == "cpu" and is_torch_version(">=", "2.5"),
+        reason="Test currently fails on CPU and PyTorch 2.5.1 but not on PyTorch 2.4.1.",
+        strict=False,
+    )
+    def test_lora_fuse_nan(self):
+        for scheduler_cls in self.scheduler_classes:
+            components, text_lora_config, denoiser_lora_config = self.get_dummy_components(scheduler_cls)
+            pipe = self.pipeline_class(**components)
+            pipe = pipe.to(torch_device)
+            pipe.set_progress_bar_config(disable=None)
+            _, _, inputs = self.get_dummy_inputs(with_generator=False)
+
+            if "text_encoder" in self.pipeline_class._lora_loadable_modules:
+                pipe.text_encoder.add_adapter(text_lora_config, "adapter-1")
+                self.assertTrue(
+                    check_if_lora_correctly_set(pipe.text_encoder), "Lora not correctly set in text encoder"
+                )
+
+            denoiser = pipe.transformer if self.unet_kwargs is None else pipe.unet
+            denoiser.add_adapter(denoiser_lora_config, "adapter-1")
+            self.assertTrue(check_if_lora_correctly_set(denoiser), "Lora not correctly set in denoiser.")
+
+            # corrupt one LoRA weight with `inf` values
+            with torch.no_grad():
+                pipe.transformer.layers[0].attn.to_q.lora_A["adapter-1"].weight += float("inf")
+
+            # with `safe_fusing=True` we should see an Error
+            with self.assertRaises(ValueError):
+                pipe.fuse_lora(components=self.pipeline_class._lora_loadable_modules, safe_fusing=True)
+
+            # without we should not see an error, but every image will be black
+            pipe.fuse_lora(components=self.pipeline_class._lora_loadable_modules, safe_fusing=False)
+            out = pipe(**inputs)[0]
+
+            self.assertTrue(np.isnan(out).all())