make compare_rendered_pictures_test.py run end-to-end test

gm/rebaseline_server/base_unittest.py

 #!/usr/bin/python
 
 """
 Copyright 2014 Google Inc.
 
 Use of this source code is governed by a BSD-style license that can be
 found in the LICENSE file.
 
 A wrapper around the standard Python unittest library, adding features we need
 for various unittests within this directory.
 """
 
 import filecmp
 import os
 import shutil
+import subprocess
 import tempfile
 import unittest
 
 PARENT_DIR = os.path.dirname(os.path.realpath(__file__))
+TRUNK_DIR = os.path.dirname(os.path.dirname(PARENT_DIR))
 TESTDATA_DIR = os.path.join(PARENT_DIR, 'testdata')
 OUTPUT_DIR_ACTUAL = os.path.join(TESTDATA_DIR, 'outputs', 'actual')
 OUTPUT_DIR_EXPECTED = os.path.join(TESTDATA_DIR, 'outputs', 'expected')
 
 
 class TestCase(unittest.TestCase):
 
   def setUp(self):
     self._input_dir = os.path.join(TESTDATA_DIR, 'inputs')
     self._output_dir_actual   = os.path.join(OUTPUT_DIR_ACTUAL, self.id())
@@ skipping 22 matching lines @@
         ('found differing files:\n' +
          '\n'.join(['tkdiff %s %s &' % (
              os.path.join(self._output_dir_actual, basename),
              os.path.join(self._output_dir_expected, basename))
                     for basename in different_files]))
 
   def shortDescription(self):
     """Tell unittest framework to not print docstrings for test cases."""
     return None
 
+  def run_command(self, args):

[borenet, 2014/05/07 18:47:49]

Why not just use subprocess.check_output which seems to do the same thing?

[epoger, 2014/05/07 19:27:49]

Because I'm stupid, that's why.

+    """Runs a program from the command line and returns stdout.
+
+    Args:
+      args: Command line to run, as a list of string parameters. args[0] is the
+            binary to run.
+
+    Returns:
+      stdout from the program, as a single string.
+
+    Raises:
+      Exception: the program exited with a nonzero return code.
+    """
+    proc = subprocess.Popen(args,
+                            stdout=subprocess.PIPE,
+                            stderr=subprocess.PIPE)
+    (stdout, stderr) = proc.communicate()
+    if proc.returncode is not 0:
+      raise Exception('command "%s" failed: %s' % (args, stderr))
+    return stdout
+
+  def find_path_to_program(self, program):
+    """Returns path to an existing program binary.
+
+    Args:
+      program: Basename of the program to find (e.g., 'render_pictures').
+
+    Returns:
+      Absolute path to the program binary, as a string.
+
+    Raises:
+      Exception: unable to find the program binary.
+    """
+    possible_paths = [os.path.join(TRUNK_DIR, 'out', 'Release', program),
+                      os.path.join(TRUNK_DIR, 'out', 'Debug', program),
+                      os.path.join(TRUNK_DIR, 'out', 'Release',
+                                   program + '.exe'),
+                      os.path.join(TRUNK_DIR, 'out', 'Debug',
+                                   program + '.exe')]
+    for try_path in possible_paths:
+      if os.path.isfile(try_path):
+        return try_path
+    raise Exception('cannot find %s in paths %s; maybe you need to '
+                    'build %s?' % (program, possible_paths, program))
+
 
 def create_empty_dir(path):
   """Create an empty directory at the given path."""
   if os.path.isdir(path):
     shutil.rmtree(path)
   elif os.path.lexists(path):
     os.remove(path)
   os.makedirs(path)
 
 
@@ skipping 22 matching lines @@
   for common_dir in dircmp.common_dirs:
     differing_files.extend(find_different_files(
         os.path.join(dir1, common_dir), os.path.join(dir2, common_dir)))
   return differing_files
 
 
 def main(test_case_class):
   """Run the unit tests within the given class."""
   suite = unittest.TestLoader().loadTestsFromTestCase(test_case_class)
   results = unittest.TextTestRunner(verbosity=2).run(suite)