improve coverage

tests/node_tests/image_demo.py

@@ -9,17 +9,23 @@ import backend.nodes  # noqa: F401
 
 def test_load_demo():
     from backend.nodes.image_demo import ImageDemo
+    from backend.nodes.helpers import DEMO_DIR
     node = ImageDemo()
 
     result = node.load(name="nanoparticles.npy")
-    assert len(result) >= 1
-    assert isinstance(result[0], DataField)
-    assert result[0].data.ndim == 2
+    # result[0] is the FILE_PATH string, fields follow
+    assert len(result) >= 2
+    assert isinstance(result[0], str)
+    assert isinstance(result[1], DataField)
+    assert result[1].data.ndim == 2
 
-    result_ibw = node.load(name="whiskers.ibw")
-    assert len(result_ibw) == 4
-    for field in result_ibw:
-        assert isinstance(field, DataField)
+    ibw_path = DEMO_DIR / "whiskers.ibw"
+    if ibw_path.exists():
+        result_ibw = node.load(name="whiskers.ibw")
+        fields = [v for v in result_ibw if isinstance(v, DataField)]
+        assert len(fields) == 4
+        for field in fields:
+            assert isinstance(field, DataField)
 
     try:
         node.load(name="nonexistent_file.png")
@@ -36,21 +42,26 @@ def test_load_demo_cache():
     Image._load_fields_cached.cache_clear()
 
     with patch.object(Image, "_load_image_or_array", wraps=Image._load_image_or_array) as loader:
-        first, = node.load(name="nanoparticles.npy")
-        second, = node.load(name="nanoparticles.npy")
+        _, first = node.load(name="nanoparticles.npy")
+        _, second = node.load(name="nanoparticles.npy")
         assert loader.call_count == 1
 
     assert np.allclose(first.data, second.data)
     assert first is not second
     first.data[0, 0] = -999.0
 
-    third, = node.load(name="nanoparticles.npy")
+    _, third = node.load(name="nanoparticles.npy")
     assert third.data[0, 0] != -999.0
 
     Image._load_fields_cached.cache_clear()
 
 
 def test_load_demo_multi_layer_preview_payload():
+    from backend.nodes.helpers import DEMO_DIR
+    ibw_path = DEMO_DIR / "whiskers.ibw"
+    if not ibw_path.exists():
+        return
+
     previews = []
     prompt = {
         "1": {