Better failure messages for assertScreenshot

python-needle · Oct 7, 2011 · 079a718 · 079a718
1 parent e26e9b5
commit 079a718
Showing 1 changed file with 7 additions and 1 deletion.
diff --git a/needle/cases.py b/needle/cases.py
@@ -69,7 +69,13 @@ def assertScreenshot(self, element, name, threshold=0.1):
         else:
             image = Image.open(filename)
             diff = ImageDiff(element.get_screenshot(), image)
-            self.assertAlmostEqual(diff.get_distance(), 0, delta=threshold)
+            distance = abs(diff.get_distance())
+            if distance > threshold:
+                raise AssertionError("The saved screenshot for '%s' did not match "
+                                     "the screenshot captured (by a distance of %.2f)" 
+                                     % (name, distance))
+
+