Fix runtime validation entrypoint and export test

tests/runtime/run_runtime_validation.py

@@ -13,8 +13,6 @@ from io import StringIO
 from pathlib import Path
 from typing import Callable
 
-from comfyui_to_python_utils import get_comfyui_path
-
 ROOT = Path(__file__).resolve().parents[2]
 FIXTURE_DIR = ROOT / "tests" / "fixtures" / "runtime"
 GENERATED_DIR = ROOT / "tests" / "runtime" / "generated"
@@ -24,6 +22,8 @@ COMFYUI_INPUT_DIRNAME = "input"
 if str(ROOT) not in sys.path:
     sys.path.insert(0, str(ROOT))
 
+from comfyui_to_python_utils import get_comfyui_path
+
 
 class ValidationFailure(RuntimeError):
     def __init__(self, classification: str, message: str):

tests/test_upscale_model_loader_export.py

@@ -95,7 +95,7 @@ class UpscaleModelLoaderExportTest(unittest.TestCase):
         generated = output.getvalue()
 
         self.assertIn("from nodes import NODE_CLASS_MAPPINGS", generated)
-        self.assertIn("from tests.test_upscale_model_loader_export import (", generated)
+        self.assertIn(f"from {LoadImage.__module__} import (", generated)
         self.assertIn("LoadImage,", generated)
         self.assertIn("UpscaleModelLoader,", generated)
         self.assertIn("ImageUpscaleWithModel,", generated)
@@ -145,6 +145,30 @@ class UpscaleModelLoaderExportTest(unittest.TestCase):
         self.assertIn('"nodes": []', generated)
         self.assertNotIn('"source": "workflow_api"', generated)
 
+    def test_export_without_frontend_workflow_leaves_png_workflow_metadata_absent(self):
+        workflow = {
+            "1": {
+                "class_type": "LoadImage",
+                "inputs": {
+                    "image": "example.png",
+                },
+            }
+        }
+
+        output = StringIO()
+        ComfyUItoPython(
+            workflow=json.dumps(workflow),
+            output_file=output,
+            node_class_mappings={
+                "LoadImage": LoadImage,
+            },
+        )
+
+        generated = output.getvalue()
+
+        self.assertIn("extra_pnginfo = None", generated)
+        self.assertNotIn('"workflow": json.loads(', generated)
+
     def test_run_accepts_frontend_workflow_file_for_cli_metadata(self):
         workflow = {
             "1": {