Clean the machine before running commands in the mini_installer test framework.

chrome/test/mini_installer/test_installer.py

 # Copyright 2013 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.
 
 """This script tests the installer with test cases specified in the config file.
 
 For each test case, it checks that the machine states after the execution of
 each command match the expected machine states. For more details, take a look at
 the design documentation at http://goo.gl/Q0rGM6
 """
@@ skipping 51 matching lines @@
     """
     return 'Test: %s' % (' -> '.join(self._test))
 
   def runTest(self):
     """Run the test case."""
     # |test| is an array of alternating state names and action names, starting
     # and ending with state names. Therefore, its length must be odd.
     self.assertEqual(1, len(self._test) % 2,
                      'The length of test array must be odd')
 
-    # TODO(sukolsak): run a reset command that puts the machine in clean state.
+    self._RunCleanCommand()
 
     state = self._test[0]
     self._VerifyState(state)
 
     # Starting at index 1, we loop through pairs of (action, state).
     for i in range(1, len(self._test), 2):
       action = self._test[i]
       self._RunCommand(self._config.actions[action])
 
       state = self._test[i + 1]
@@ skipping 28 matching lines @@
     Args:
       command: A command to run. It is expanded using ResolvePath.
     """
     resolved_command = self._path_resolver.ResolvePath(command)
     script_dir = os.path.dirname(os.path.abspath(__file__))
     exit_status = subprocess.call(resolved_command, shell=True, cwd=script_dir)
     if exit_status != 0:
       self.fail('Command %s returned non-zero exit status %s' % (
           resolved_command, exit_status))
 
+  def _RunCleanCommand(self):
+    """Puts the machine in the clean state (i.e. Chrome not installed)."""
+    # TODO(sukolsak): Read the clean state from the config file and clean
+    # the machine according to it.

[robertshield, 2013/09/10 20:59:31]

Also, consider adding a TODO to handle SxS installs (what canary does).

[sukolsak, 2013/09/10 21:26:29]

Done.

+    command = ('python uninstall_chrome.py '
+               '--chrome-long-name="$CHROME_LONG_NAME" & '

[robertshield, 2013/09/10 20:59:31]

Just to double check: it is my understanding that if either of these fail, then
they will print an informative error message to stdout or stderr. Is that
correct?

[sukolsak, 2013/09/10 21:26:29]

They will print an error message to stderr. For example, if Chrome is not
installed, they will complain that they can't find the registry key for the
uninstall command. The error message is not really useful because our goal is to
remove everything. We just give the uninstaller a chance to do a preliminary
cleanup before we do it ourselves.

+               'python uninstall_chrome.py '
+               '--chrome-long-name="$CHROME_LONG_NAME" --system-level')
+    resolved_command = self._path_resolver.ResolvePath(command)
+    script_dir = os.path.dirname(os.path.abspath(__file__))
+    subprocess.call(resolved_command, shell=True, cwd=script_dir,
+                    stderr=open(os.devnull, 'w'))
+
 
 def MergePropertyDictionaries(current_property, new_property):
   """Merges the new property dictionary into the current property dictionary.
 
   This is different from general dictionary merging in that, in case there are
   keys with the same name, we merge values together in the first level, and we
   override earlier values in the second level. For more details, take a look at
   http://goo.gl/uE0RoR
 
   Args:
@@ skipping 90 matching lines @@
   assert os.path.exists(mini_installer_path), ('Could not find file %s' %
                                                mini_installer_path)
   config = ParseConfigFile(config_filename)
   if not RunTests(mini_installer_path, config):
     return 1
   return 0
 
 
 if __name__ == '__main__':
   sys.exit(main())