Add a visual test to verify the check_window() method

Author: mdmintz

examples/visual_test.py

@@ -0,0 +1,25 @@
+from seleniumbase import BaseCase
+
+
+class AutomatedVisualTest(BaseCase):
+
+    def test_applitools_helloworld(self):
+        self.open('https://applitools.com/helloworld?diff1')
+        print('Creating baseline in "visual_baseline" folder...')
+        self.check_window(name="helloworld", baseline=True)
+        self.click('a[href="?diff1"]')
+        # Verify html tags match previous version
+        self.check_window(name="helloworld", level=1)
+        # Verify html tags + attributes match previous version
+        self.check_window(name="helloworld", level=2)
+        # Verify html tags + attributes + values match previous version
+        self.check_window(name="helloworld", level=3)
+        # Change the page enough for a Level-3 comparison to fail
+        self.click("button")
+        self.check_window(name="helloworld", level=1)
+        self.check_window(name="helloworld", level=2)
+        with self.assertRaises(Exception):
+            self.check_window(name="helloworld", level=3)
+        # Now that we know the exception was raised as expected,
+        # let's print out the comparison results by running in Level-0.
+        self.check_window(name="helloworld", level=0)