Changed selenium tests to recover from test crashes/hangs. Divided perceptual...

tests/selenium/pdiff_test.py

Index: tests/selenium/pdiff_test.py
===================================================================
--- tests/selenium/pdiff_test.py	(revision 0)
+++ tests/selenium/pdiff_test.py	(revision 0)
@@ -0,0 +1,139 @@
+import os
+import re
+import subprocess
+import unittest
+import sys
+
+import selenium_utilities
+import selenium_constants
+
+class PDiffTest(unittest.TestCase):
+  """A perceptual diff test class, for running perceptual diffs on any
+  number of screenshots."""
+  
+  def __init__(self, name, num_screenshots, screenshot_name, pdiff_path,
+               gen_dir, ref_dir, options):
+    unittest.TestCase.__init__(self, name)
+    self.name = name
+    self.num_screenshots = num_screenshots
+    self.screenshot_name = screenshot_name
+    self.pdiff_path = pdiff_path
+    self.gen_dir = gen_dir
+    self.ref_dir = ref_dir
+    self.options = options
+
+  def shortDescription(self):
+    """override unittest.TestCase shortDescription for our own descriptions."""
+    return "Screenshot comparison for: " + self.name
+    
+  def PDiffTest(self):
+    """Runs a generic Perceptual Diff test."""
+    # Get arguments for perceptual diff.
+    pixel_threshold = "10"
+    alpha_threshold = "1.0"
+    use_colorfactor = False
+    use_downsample = False
+    use_edge = True
+    edge_threshold = "5"
+
+    for opt in self.options:
+      if opt.startswith("pdiff_threshold"):
+        pixel_threshold = selenium_utilities.GetArgument(opt)
+      elif (opt.startswith("pdiff_threshold_mac") and
+            sys.platform == "darwin"):
+        pixel_threshold = selenium_utilities.GetArgument(opt)
+      elif (opt.startswith("pdiff_threshold_win") and
+            sys.platform == 'win32' or sys.platform == "cygwin"):
+        pixel_threshold = selenium_utilities.GetArgument(opt)
+      elif (opt.startswith("pdiff_threshold_linux") and
+            sys.platform[:5] == "linux"):
+        pixel_threshold = selenium_utilities.GetArgument(opt)
+      elif (opt.startswith("colorfactor")):
+        colorfactor = selenium_utilities.GetArgument(opt)
+        use_colorfactor = True
+      elif (opt.startswith("downsample")):
+        downsample_factor = selenium_utilities.GetArgument(opt)
+        use_downsample = True
+      elif (opt.startswith("pdiff_edge_ignore_off")):
+        use_edge = False
+      elif (opt.startswith("pdiff_edge_threshold")):
+        edge_threshold = selenium_utilities.GetArgument(opt)
+
+    results = []
+    # Loop over number of screenshots.
+    for screenshot_no in range(self.num_screenshots):
+      # Find reference image.
+      J = os.path.join
+      platform_img_path = J(self.ref_dir,
+                            selenium_constants.PLATFORM_SCREENSHOT_DIR,
+                            self.screenshot_name + str(screenshot_no + 1) +
+                            '_reference.png')
+      reg_img_path = J(self.ref_dir,
+                       selenium_constants.DEFAULT_SCREENSHOT_DIR,
+                       self.screenshot_name + str(screenshot_no + 1) +
+                       '_reference.png')
+
+      if os.path.exists(platform_img_path):
+        ref_img_path = platform_img_path
+      elif os.path.exists(reg_img_path):
+        ref_img_path = reg_img_path
+      else:
+        self.fail('Reference image for ' + self.screenshot_name + ' not found.'
+                  + '\nNeither file exists %s NOR %s' %
+                  (reg_img_path, platform_img_path))
+  
+      # Find generated image.
+      gen_img_path = J(self.gen_dir, self.screenshot_name +
+                       str(screenshot_no + 1) + '.png')
+      diff_img_path = J(self.gen_dir, 'cmp_' + self.screenshot_name +
+                        str(screenshot_no + 1) + '.png')
+       
+      self.assertTrue(os.path.exists(gen_img_path),
+                      'Generated screenshot for ' + self.screenshot_name +
+                      ' not found.\nFile does not exist: %s' % gen_img_path)
+
+      # Run perceptual diff
+      arguments = [self.pdiff_path,
+                   ref_img_path,
+                   gen_img_path,
+                   "-output", diff_img_path,
+                   "-fov", "45",
+                   "-alphaThreshold", alpha_threshold,
+                   # Turn on verbose output for the percetual diff so we
+                   # can see how far off we are on the threshold.
+                   "-verbose",
+                   # Set the threshold to zero so we can get a count
+                   # of the different pixels.  This causes the program
+                   # to return failure for most images, but we can compare
+                   # the values ourselves below.
+                   "-threshold", "0"]
+      if use_colorfactor:
+        arguments += ["-colorfactor", colorfactor]
+      if use_downsample:
+        arguments += ["-downsample", downsample_factor]
+      if use_edge:
+        arguments += ["-ignoreEdges", edge_threshold]
+
+      pdiff_pipe = subprocess.Popen(arguments,
+                                    stdout=subprocess.PIPE,
+                                    stderr=subprocess.PIPE)
+      (pdiff_stdout, pdiff_stderr) = pdiff_pipe.communicate()
+      result = pdiff_pipe.returncode
+      # Find out how many pixels were different by looking at the output.
+      pixel_re = re.compile("(\d+) pixels are different", re.DOTALL)
+      pixel_match = pixel_re.search(pdiff_stdout)
+      different_pixels = "0"
+      if pixel_match:
+        different_pixels = pixel_match.group(1)
+
+      results += [(gen_img_path, int(different_pixels))]
+
+    all_tests_passed = True
+    msg = "Pixel Threshold is %s. Failing screenshots:\n" % pixel_threshold
+    for path, pixels in results:
+      if pixels >= pixel_threshold:
+        all_tests_passed = False
+        msg += "     %s, differing by %s\n" % (path, str(pixels))
+
+    if not all_tests_passed:
+      self.assertTrue(all_tests_passed, msg)