feat: added reference utils to compare renderings of widgets

tests/unit_tests/test_spinner.py

@@ -1,11 +1,7 @@
-import os
-import sys
-
 import pytest
 import qdarktheme
-from PIL import Image, ImageChops
-from qtpy.QtGui import QPixmap
 
+from bec_widgets.utils.reference_utils import snap_and_compare
 from bec_widgets.widgets.spinner.spinner import SpinnerWidget
 
 
@@ -18,75 +14,17 @@ def spinner_widget(qtbot):
     yield spinner
 
 
-def save_pixmap(widget, filename):
-    pixmap = QPixmap(widget.size())
-    widget.render(pixmap)
-    pixmap.save(str(filename))
-    return pixmap
-
-
-def compare_images(image1_path: str, reference_image_path: str):
-    image1 = Image.open(image1_path)
-    image2 = Image.open(reference_image_path)
-    if image1.size != image2.size:
-        raise ValueError("Image size has changed")
-    diff = ImageChops.difference(image1, image2)
-    if diff.getbbox():
-        # copy image1 to the reference directory to upload as artifact
-        output_dir = os.path.join(os.path.dirname(__file__), "reference_failures")
-        os.makedirs(output_dir, exist_ok=True)
-        image_name = os.path.join(output_dir, os.path.basename(image1_path))
-        image1.save(image_name)
-        print(f"Image saved to {image_name}")
-
-        raise ValueError("Images are different")
-
-
 def test_spinner_widget_paint_event(spinner_widget, qtbot):
     spinner_widget.paintEvent(None)
 
 
-def snap_and_compare(widget, tmpdir, suffix=""):
-    os_suffix = sys.platform
-
-    name = (
-        f"{widget.__class__.__name__}_{suffix}_{os_suffix}.png"
-        if suffix
-        else f"{widget.__class__.__name__}_{os_suffix}.png"
-    )
-
-    # Save the widget to a pixmap
-    test_image_path = str(tmpdir / name)
-    pixmap = QPixmap(widget.size())
-    widget.render(pixmap)
-    pixmap.save(test_image_path)
-
-    try:
-        references_path = os.path.join(os.path.dirname(__file__), "references")
-        reference_image_path = os.path.join(references_path, name)
-
-        if not os.path.exists(reference_image_path):
-            raise ValueError(f"Reference image not found: {reference_image_path}")
-
-        compare_images(test_image_path, reference_image_path)
-
-    except ValueError:
-        image = Image.open(test_image_path)
-        output_dir = os.path.join(os.path.dirname(__file__), "reference_failures")
-        os.makedirs(output_dir, exist_ok=True)
-        image_name = os.path.join(output_dir, name)
-        image.save(image_name)
-        print(f"Image saved to {image_name}")
-        raise
-
-
 def test_spinner_widget_rendered(spinner_widget, qtbot, tmpdir):
     spinner_widget.update()
     qtbot.wait(200)
-    snap_and_compare(spinner_widget, tmpdir, suffix="")
+    snap_and_compare(spinner_widget, str(tmpdir), suffix="")
 
     spinner_widget._started = True
     spinner_widget.update()
     qtbot.wait(200)
 
-    snap_and_compare(spinner_widget, tmpdir, suffix="started")
+    snap_and_compare(spinner_widget, str(tmpdir), suffix="started")