Reduce code duplication in multiple copies of test_env.py.

appengine/isolate/tests/test_env.py

 # Copyright 2013 The Swarming Authors. All rights reserved.
 # Use of this source code is governed by the Apache v2.0 license that can be
 # found in the LICENSE file.
 
 import os
 import sys
 
 # isolate/
 APP_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
-# components/ (NOT isolate/components/).
-COMPONENTS_DIR = os.path.join(os.path.dirname(APP_DIR), 'components')
-
-_INITIALIZED = False
 
 
 def setup_test_env():
   """Sets up App Engine test environment."""
-  global _INITIALIZED
-  if _INITIALIZED:
-    raise Exception('Do not call test_env.setup_test_env() twice.')
-  _INITIALIZED = True
-
-  # For 'from test_support import ...'
-  sys.path.insert(0, COMPONENTS_DIR)
-  # For dependencies of support code.
-  sys.path.insert(0, os.path.join(COMPONENTS_DIR, 'third_party'))
-
-  # For unit tests not importing main.py, which should be ALL unit tests.
-  sys.path.insert(0, os.path.join(APP_DIR, 'components', 'third_party'))
   # For dependencies of app itself.
   sys.path.insert(0, os.path.join(APP_DIR, 'third_party'))
   # For application modules.
   sys.path.insert(0, APP_DIR)
 
-  from test_support import gae_sdk_utils
-  gae_sdk_dir = gae_sdk_utils.find_gae_sdk()
-  if not gae_sdk_dir:
-    raise Exception('Unable to find gae sdk path, aborting test.')
-
-  gae_sdk_utils.setup_gae_sdk(gae_sdk_dir)
-  gae_sdk_utils.setup_env(APP_DIR, None, None, None)
+  from test_support import test_env
+  test_env.setup_test_env()