[FIX] mock infer in diffusers pipeline inferencer ut. (open-mmlab#2026)

mock infer

tests/test_apis/test_inferencers/test_diffusers_pipeline_inferencer.py

@@ -26,15 +26,10 @@ def test_diffusers_pipeline_inferencer():
 
     inferencer_instance = DiffusersPipelineInferencer(cfg, None)
 
-    def mock_encode_prompt(prompt, do_classifier_free_guidance,
-                           num_images_per_prompt, *args, **kwargs):
-        batch_size = len(prompt) if isinstance(prompt, list) else 1
-        batch_size *= num_images_per_prompt
-        if do_classifier_free_guidance:
-            batch_size *= 2
-        return torch.randn(batch_size, 5, 16)  # 2 for cfg
-
-    inferencer_instance.model._encode_prompt = mock_encode_prompt
+    def mock_infer(*args, **kwargs):
+        return dict(samples=torch.randn(1, 3, 64, 64))
+
+    inferencer_instance.model.infer = mock_infer
 
     text_prompts = 'Japanese anime style, girl'
     negative_prompt = 'bad face, bad hands'