test(approvaltests reporter): create png if not exists

Author: matthiasschaub

tests/approvaltests_reporters.py

@@ -16,6 +16,7 @@
 from approvaltests.reporters.report_with_diff_command_line import (
     ReportWithDiffCommandLine,
 )
+from PIL import Image
 
 
 class BlockingGenericDiffReporter(GenericDiffReporter):
@@ -172,6 +173,9 @@ def report(self, received_path: str, approved_path: str) -> bool:
                 raw = json.load(file)
             approved_figure = pgo.Figure(raw)
             approved_figure.write_image(approved_path_image)
+        else:
+            image = Image.new("RGB", (1, 1))
+            image.save(approved_path_image, "PNG")
 
         with open(received_path, "r") as file:
             raw = json.load(file)