Add mojo apptest runner.

mojo/tools/gtest.py

Index: mojo/tools/gtest.py
diff --git a/mojo/tools/gtest.py b/mojo/tools/gtest.py
new file mode 100644
index 0000000000000000000000000000000000000000..a731115ae5e777424932a1f33d793b94289ae654
--- /dev/null
+++ b/mojo/tools/gtest.py
@@ -0,0 +1,105 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import logging
+import os
+import re
+import subprocess
+import sys
+
+_logging = logging.getLogger()
+
+def _print_process_error(command_line, error):
+  """Properly format an exception raised from a failed command execution."""
+
+  if command_line:
+    print 'Failed command: %r' % command_line
+  else:
+    print 'Failed command:'
+  print 72 * '-'
+
+  if hasattr(error, 'returncode'):
+    print '  with exit code %d' % error.returncode
+    print 72 * '-'
+
+  if hasattr(error, 'output'):
+    print error.output
+  else:
+    print error
+  print 72 * '-'
+
+def set_color():
+  """Run gtests with color if we're on a TTY (and we're not being told
+  explicitly what to do)."""
+  if sys.stdout.isatty() and 'GTEST_COLOR' not in os.environ:
+    _logging.debug("Setting GTEST_COLOR=yes")
+    os.environ['GTEST_COLOR'] = 'yes'
+
+
+def _try_command_line(command_line):
+  """Returns the output of a command line or an empty string on error."""
+  _logging.debug("Running command line: %s" % command_line)
+  try:
+    return subprocess.check_output(command_line, stderr=subprocess.STDOUT)
+  except Exception as e:
+    _print_process_error(command_line, e)
+  return None
+
+
+def run_test(command_line):
+  """Runs a command line and checks the output for signs of gtest failure."""
+  output = _try_command_line(command_line)
+  # Fail on output with gtest's "[  FAILED  ]" or a lack of "[  PASSED  ]".
+  # The latter condition ensures failure on broken command lines or output.
+  # Check output instead of exit codes because mojo_shell always exits with 0.
+  if (output is None or
+      (output.find("[  FAILED  ]") != -1 or output.find("[  PASSED  ]") == -1)):
+    print "Failed test:"
+    _print_process_error(command_line, output)
+    return False
+  _logging.debug("Succeeded with output:\n%s" % output)
+  return True
+
+
+def get_fixtures(mojo_shell, apptest):
+  """Returns the "Test.Fixture" list from an apptest using mojo_shell.
+
+  Tests are listed by running the given apptest in mojo_shell and passing
+  --gtest_list_tests. The output is parsed and reformatted into a list like
+  [TestSuite.TestFixture, ... ]
+  An empty list is returned on failure, with errors logged.
+  """
+  command = [mojo_shell,
+             "--args-for={0} --gtest_list_tests".format(apptest),
+             apptest]
+  try:
+    list_output = subprocess.check_output(command, stderr=subprocess.STDOUT)
+    _logging.debug("Tests listed:\n%s" % list_output)
+    return _gtest_list_tests(list_output)
+  except Exception as e:
+    print "Failed to get test fixtures:"
+    _print_process_error(command, e)
+  return []
+
+
+def _gtest_list_tests(gtest_list_tests_output):
+  """Returns a list of strings formatted as TestSuite.TestFixture from the
+  output of running --gtest_list_tests on a GTEST application."""
+
+  if not re.match("^(\w*\.\r?\n(  \w*\r?\n)+)+", gtest_list_tests_output):
+    raise Exception("Unrecognized --gtest_list_tests output:\n%s" %
+                    gtest_list_tests_output)
+
+  output_lines = gtest_list_tests_output.split('\n')
+
+  test_list = []
+  for line in output_lines:
+    if not line:
+      continue
+    if line[0] != ' ':
+      suite = line.strip()
+      continue
+    test_list.append(suite + line.strip())
+
+  return test_list