@@ -1,2 +1,3 @@ .DS_Store -*.pyc \ No newline at end of file +*.pyc +sample/* .gitignore @@ -4,12 +4,14 @@ CSS is hard to test automatically. Their appear to be two potential approaches which might have merit in solving this problem and and this sample code represents one of them. -The idea is to check whether a URL or segment of a given URL looks identical -to a reference image. +The basic idea resolves around programatic comparison of images, some based on +screen shots and others generated dynamically from URLs. The capability to +analyse only a segment of a page has also been included. The overhead introduced by the need to take screenshots of a site makes this technique more useful for spotting regression issues in a live site than for -a test driven approach to writing CSS. +a test driven approach to writing CSS. Tools will be provided to make this +easier at a later date. As this is currently a proof of concept in that it only supports testing in webkit, and even then only on OS X. Support for other browsers relies on @@ -46,7 +48,7 @@ class CSSTests(unittest.TestCase): else: self.assert_(False, "%s and %s are not identical" % (expected, actual)) - commands.getoutput("rm diff.png") + #commands.getoutput("rm diff.png") def assert_image_and_url_same(self, image, url): """ @@ -65,7 +67,33 @@ class CSSTests(unittest.TestCase): self.assert_(False, "the page found at %s does not look like %s" % (url, image)) commands.getoutput("rm %s-full.png" % filename) - commands.getoutput("rm diff.png") + #commands.getoutput("rm diff.png") + + def assert_urls_same(self, expected, actual): + """ + Check that two specified urls are visualy identical + """ + commands.getoutput("webkit2png -F %s" % expected) + expected_filename = re.sub('\W', '', expected) + expected_filename = re.sub('^http', '', expected_filename) + expected_filename = "%s-full.png" % expected_filename + + + commands.getoutput("webkit2png -F %s" % actual) + actual_filename = re.sub('\W', '', actual) + actual_filename = re.sub('^http', '', actual_filename) + actual_filename = "%s-full.png" % actual_filename + + output = commands.getoutput("compare -metric PSNR %s %s diff.png" + % (expected_filename, actual_filename)) + if output == "inf": + self.assert_(True) + else: + self.assert_(False, "the page found at %s does not look like %s" + % (actual, expected)) + commands.getoutput("rm %s-full.png" % expected_filename) + commands.getoutput("rm %s-full.png" % actual_filename) + #commands.getoutput("rm diff.png") def assert_image_and_url_segment_same(self, image, url, segment): """ @@ -89,7 +117,7 @@ class CSSTests(unittest.TestCase): % (url, image)) commands.getoutput("rm %s-full.png" % filename) commands.getoutput("rm %s-segment.png" % filename) - commands.getoutput("rm diff.png") + #commands.getoutput("rm diff.png") class SampleCSSTests(CSSTests): """ @@ -104,7 +132,6 @@ class SampleCSSTests(CSSTests): commands.getoutput("rm localhost8000-full.png") def test_assert_image_and_url_same(self): - image = "sample/localhost8000-full.png" url = "http://localhost:8000" self.assert_image_and_url_same(image, url) @@ -115,5 +142,10 @@ class SampleCSSTests(CSSTests): segment = "500x500+200+200" self.assert_image_and_url_segment_same(image, url, segment) + def test_assert_urls_same(self): + expected = "http://localhost:8000" + actual = "http://localhost:8000" + self.assert_urls_same(expected, actual) + if __name__ == "__main__": unittest.main() \ No newline at end of file test_image.py 4285f51235d06fd8d0f2fa578a8095bb70d8d9b0 Gareth Rushgrove gareth@morethanseven.net http://github.com/garethr/css-test/commit/a1b9163ced7c6941d0cc94feb66ba7ec82406cae a1b9163ced7c6941d0cc94feb66ba7ec82406cae 2008-11-22T04:32:18-08:00 2008-11-22T04:32:18-08:00 ignore sample folder in gitignore f8f21126c353b690a5ff14f932ed5210a5158689 Gareth Rushgrove gareth@morethanseven.net