Initial commit for the Automated Installer Testing 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 a series of 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
+"""
+
+import optparse

[gab, 2013/08/05 15:43:48]

nit: Fix alphabetical order of imports

[sukolsak, 2013/08/05 18:03:51]

Done.

+import json
+import os
+import settings
+import subprocess
+import verifier
+
+
+class Config:
+  """Describes the machine states, actions, and test cases.
+
+  A state is a dictionary where each key is a verifier's name and the
+  associated value is the input to that verifier. An action is a shorthand for
+  a command. A test is array of alternating state names and action names,
+  starting and ending with state names. An instance of this class stores a map
+  from state names to state objects, a map from action names to commands, and
+  an array of test objects.
+  """
+  def __init__(self):
+    self.states = {}
+    self.actions = {}
+    self.tests = []
+
+
+def MergeProperties(current_property, new_property):
+  """Merges the new Property object into the current Property object
+
+  Args:
+    current_property: The Property object to be modified.
+    new_property: The new Property object.
+  """
+  for key, value in new_property.iteritems():
+    if key not in current_property:
+      current_property[key] = value
+    else:
+      assert(isinstance(current_property[key], dict) and
+          isinstance(value, dict))
+      # This merges two dictionaries together. In case there are properties with
+      # the same name, the latter will override the former.
+      current_property[key] = dict(
+          current_property[key].items() + value.items())
+
+
+def ParseProperty(directory, property_filename):
+  """Parses a .prop file.
+
+  Args:
+    property_filename: A Property filename.
+    directory: The directory where the Config file and all Property files
+        reside in.
+
+  Returns:
+    A Property object.
+  """
+  property_path = os.path.join(directory, property_filename)
+  with open(property_path, "r") as property_file:
+    return json.load(property_file)
+
+
+def ParseProperties(directory, property_filenames):
+  """Parses an array of .prop files.
+
+  Args:
+    property_filenames: An array of Property filenames.
+    directory: The directory where the Config file and all Property files
+        reside in.
+
+  Returns:
+    A Property object created by merging all Property objects specified in
+        the array.
+  """
+  current_property = {}
+  for property_filename in property_filenames:
+    new_property = ParseProperty(directory, property_filename)
+    MergeProperties(current_property, new_property)
+  return current_property
+
+
+def ParseConfig(config_filename):
+  """Parses a .config file.
+
+  Args:
+    config_filename: A Config filename.
+
+  Returns:
+    A config object.
+  """
+  config = Config()
+
+  with open(config_filename, "r") as config_file:
+    config_data = json.load(config_file)
+  directory = os.path.dirname(os.path.abspath(config_filename))
+
+  for state_name, state_property_filenames in config_data["states"]:
+    config.states[state_name] = ParseProperties(directory,
+                                                state_property_filenames)
+  for action_name, action_command in config_data["actions"]:
+    config.actions[action_name] = action_command
+  config.tests = config_data["tests"]
+  return config
+
+
+def VerifyState(config, state):
+  """Verifies that the current machine states match the given machine states.
+
+  Args:
+    config: A Config object.
+    state: The current state.
+  """
+  # TODO(sukolsak): Think of ways of preserving the log when the test fails but
+  # not printing these when the test passes.
+  print settings.PRINT_STATE_PREFIX + state
+  verifier.Verify(config.states[state])
+
+
+def RunCommand(command):
+  print settings.PRINT_COMMAND_PREFIX + command
+  subprocess.call(command, shell=True)
+
+
+def RunResetCommand():
+  print settings.PRINT_COMMAND_PREFIX + "Reset"
+  # TODO(sukolsak): Need to figure how exactly we want to reset.
+
+
+def Test(config):
+  """Tests the installer using the given Config object.
+
+  Args:
+    config: A Config object.
+  """
+  for test in config.tests:
+    print settings.PRINT_TEST_PREFIX + " -> ".join(test)
+
+    # A Test object is an array of alternating state names and action names.
+    # The array starts and ends with states. Therefore, the length must be odd.
+    assert(len(test) % 2 == 1)
+
+    RunResetCommand()
+
+    current_state = test[0]
+    VerifyState(config, current_state)
+    # TODO(sukolsak): Quit the test early if VerifyState fails at any point.
+
+    for i in range(1, len(test), 2):
+      action = test[i]
+      RunCommand(config.actions[action])
+
+      current_state = test[i + 1]
+      VerifyState(config, current_state)
+
+
+def main():
+  usage = "usage: %prog configfile"
+  parser = optparse.OptionParser(usage, description="Test the installer.")

[gab, 2013/08/05 15:43:48]

Use parser.add_option, see
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/tools/build...
for an example.

[sukolsak, 2013/08/05 18:03:51]

add_option doesn't support required arguments. The Python doc recommends using
positional arguments for required arguments instead of adding options.
http://docs.python.org/2/library/optparse.html#what-are-options-for 

[gab, 2013/08/05 18:13:05]

I see then the error message below should be a more verbose help message
detailing what the expected syntax is (does optparse support some kind of
generic help message; e.g., either triggered via -h/--help or forced when
incoming command-line is incorrect?).

+  (options, args) = parser.parse_args()

[gab, 2013/08/05 15:43:48]

Do not even store |args|, see
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/tools/build...

+  if len(args) != 1:
+    parser.error("incorrect number of arguments")
+
+  config = ParseConfig(args[0])
+  Test(config)
+
+
+if __name__ == "__main__":
+  main()