Handle case when no watermark config is available appropriately

Author: grst

src/dso/api.py

@@ -136,6 +136,8 @@ def WatermarkedFile(output_file: Path | str, **kwargs):
     Yields
     ------
     Temporary filename to which the non-watermarked file needs to be written.
+    If no watermark configuration is present (neither in params nor in kwargs),
+    yields the output file path directly without applying any watermark.
 
     Example
     -------
@@ -151,8 +153,11 @@ def WatermarkedFile(output_file: Path | str, **kwargs):
 
     watermark_config.update(kwargs)
 
-    with NamedTemporaryFile(suffix=output_file.suffix) as f:
-        try:
-            yield f.name
-        finally:
-            Watermarker.add_watermark(f.name, output_file, **watermark_config)
+    if not watermark_config:
+        yield output_file
+    else:
+        with NamedTemporaryFile(suffix=output_file.suffix) as f:
+            try:
+                yield f.name
+            finally:
+                Watermarker.add_watermark(f.name, output_file, **watermark_config)

tests/test_api.py

@@ -64,3 +64,21 @@ def test_watermarked_file(quarto_stage, tmp_path, format):
 
     assert output_file.exists()
     assert output_file.stat().st_size > 0
+
+
+def test_watermarked_file_no_config(quarto_stage, tmp_path):
+    """Test that WatermarkedFile yields output path directly when no watermark config is present."""
+    chdir(quarto_stage)
+    # Ensure no watermark config is set
+    dso.api.CONFIG.dso_config = {}
+
+    output_file = tmp_path / "output.png"
+
+    with WatermarkedFile(output_file) as f:
+        # When no watermark config, should yield the output file path directly
+        assert Path(f) == output_file
+        img = Image.new("RGB", (100, 100), color=(73, 109, 137))
+        img.save(f)
+
+    assert output_file.exists()
+    assert output_file.stat().st_size > 0