refactor: clarifying responsibility boundaries for folder_paths

src/nodes/_diffusers_pipeline_loader.py

@@ -28,6 +28,7 @@ class DiffusersPipelineLoader:
         checkpoint_name: str,
         handler: PipelineHandler = Provide[Container.pipeline_handler],
     ) -> tuple[ComfyUIPipelineDTO]:
-        pipeline_model = handler.create(checkpoint_name)
+        checkpoint_path = folder_paths.get_full_path("checkpoints", checkpoint_name)
+        pipeline_model = handler.create(checkpoint_path)
         pipeline_dto = ComfyUIPipelineDTO.from_domain(pipeline_model)
         return (pipeline_dto,)

src/nodes/_diffusers_vae_loader.py

@@ -28,6 +28,7 @@ class DiffusersVaeLoader:
         vae_name: str,
         handler: AutoencoderHandler = Provide[Container.autoencoder_handler],
     ) -> tuple[ComfyUIAutoencoderDTO]:
-        autoencoder_model = handler.create(vae_name)
+        vae_path = folder_paths.get_full_path("vae", vae_name)
+        autoencoder_model = handler.create(vae_path)
         autoencoder_dto = ComfyUIAutoencoderDTO.from_domain(autoencoder_model)
         return (autoencoder_dto,)

src/ui/_autoencoder_handler.py

@@ -1,7 +1,5 @@
 import os
 
-import folder_paths  # pyright: ignore[reportMissingImports]
-
 from ..domain.model import Autoencoder
 from ..service import AutoencoderService
 
@@ -10,8 +8,10 @@ class AutoencoderHandler:
     def __init__(self, autoencoder_service: AutoencoderService) -> None:
         self.create_autoencoder_service = autoencoder_service
 
-    def create(self, checkpoint_name: str) -> Autoencoder:
-        checkpoint_path = folder_paths.get_full_path("vae", checkpoint_name)
-        if not os.path.exists(checkpoint_path):
-            raise FileNotFoundError(f"VAE file not found: {checkpoint_name}")
-        return self.create_autoencoder_service.create_from_checkpoint(checkpoint_path)
+    def create(self, vae_path: str) -> Autoencoder:
+        if not os.path.exists(vae_path):
+            raise FileNotFoundError(f"VAE file not found: {vae_path}")
+        autoencoder = self.create_autoencoder_service.create_from_checkpoint(vae_path)
+        if autoencoder is None:
+            raise RuntimeError(f"Failed to create autoencoder from checkpoint: {vae_path}")
+        return autoencoder

src/ui/_pipeline_handler.py

@@ -1,7 +1,5 @@
 import os
 
-import folder_paths  # pyright: ignore[reportMissingImports]
-
 from ..domain.model import Pipeline
 from ..service import PipelineService
 
@@ -10,8 +8,10 @@ class PipelineHandler:
     def __init__(self, pipeline_service: PipelineService) -> None:
         self.create_pipeline_service = pipeline_service
 
-    def create(self, checkpoint_name: str) -> Pipeline:
-        checkpoint_path = folder_paths.get_full_path("checkpoints", checkpoint_name)
+    def create(self, checkpoint_path: str) -> Pipeline:
         if not os.path.exists(checkpoint_path):
-            raise FileNotFoundError(f"Checkpoint file not found: {checkpoint_name}")
-        return self.create_pipeline_service.create_from_checkpoint(checkpoint_path)
+            raise FileNotFoundError(f"Checkpoint file not found: {checkpoint_path}")
+        pipeline = self.create_pipeline_service.create_from_checkpoint(checkpoint_path)
+        if pipeline is None:
+            raise RuntimeError(f"Failed to create pipeline from checkpoint: {checkpoint_path}")
+        return pipeline