feat: added reference utils to compare renderings of widgets

.gitlab-ci.yml

@@ -145,7 +145,7 @@ tests:
         coverage_format: cobertura
         path: coverage.xml
     paths:
-      - tests/unit_tests/reference_failures/
+      - tests/reference_failures/
     when: always
 
 test-matrix:

bec_widgets/utils/reference_utils.py

@@ -0,0 +1,92 @@
+import os
+import sys
+
+from PIL import Image, ImageChops
+from qtpy.QtGui import QPixmap
+
+import bec_widgets
+
+REFERENCE_DIR = os.path.join(
+    os.path.dirname(os.path.dirname(bec_widgets.__file__)), "tests/references"
+)
+REFERENCE_DIR_FAILURES = os.path.join(
+    os.path.dirname(os.path.dirname(bec_widgets.__file__)), "tests/reference_failures"
+)
+
+
+def compare_images(image1_path: str, reference_image_path: str):
+    """
+    Load two images and compare them pixel by pixel
+
+    Args:
+        image1_path(str): The path to the first image
+        reference_image_path(str): The path to the reference image
+
+    Raises:
+        ValueError: If the images are different
+    """
+    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
+        os.makedirs(REFERENCE_DIR_FAILURES, exist_ok=True)
+        image_name = os.path.join(REFERENCE_DIR_FAILURES, os.path.basename(image1_path))
+        image1.save(image_name)
+        print(f"Image saved to {image_name}")
+
+        raise ValueError("Images are different")
+
+
+def snap_and_compare(widget: any, output_directory: str, suffix: str = ""):
+    """
+    Save a rendering of a widget and compare it to a reference image
+
+    Args:
+        widget(any): The widget to render
+        output_directory(str): The directory to save the image to
+        suffix(str): A suffix to append to the image name
+
+    Raises:
+        ValueError: If the images are different
+
+    Examples:
+        snap_and_compare(widget, tmpdir, suffix="started")
+
+    """
+
+    if not isinstance(output_directory, str):
+        output_directory = str(output_directory)
+
+    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 = os.path.join(output_directory, name)
+    pixmap = QPixmap(widget.size())
+    widget.render(pixmap)
+    pixmap.save(test_image_path)
+
+    try:
+        reference_path = os.path.join(REFERENCE_DIR, f"{widget.__class__.__name__}")
+        reference_image_path = os.path.join(reference_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)
+        os.makedirs(REFERENCE_DIR_FAILURES, exist_ok=True)
+        image_name = os.path.join(REFERENCE_DIR_FAILURES, name)
+        image.save(image_name)
+        print(f"Image saved to {image_name}")
+        raise

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")