Add module discovery and autoloading to expect_tests.

scripts/slave/unittests/expect_tests/unittest_helper.py

 # Copyright 2014 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 unittest
 
 from .type_definitions import Test, Result, MultiTest, FuncCall, Bind
 
+from .util import covers
+
 
 def _SetUpClass(test_class):
   inst = test_class('__init__')
   inst.setUpClass()
   return inst
 
 
 def _TearDownClass(test_class_inst):
   test_class_inst.tearDownClass()
 
 
 def _RunTestCaseSingle(test_case, test_name, test_instance=None):
   # The hack is so that unittest.TestCase has something to pretend is the
   # test method without the BS of wrapping each method in a new TestCase
   # class...
   test_instance = test_instance or test_case('__init__')
   test_instance.setUp()
   try:
     return Result(getattr(test_instance, test_name)())
   finally:
     test_instance.tearDown()
 
 
-def UnittestTestCase(test_case, name_prefix='', ext='json'):
+def UnittestTestCase(test_case):
   """Yield a MultiTest or multiple Test instances for the unittest.TestCase
   derived |test_case|.
 
   If the TestCase has a field `__expect_tests_serial__` defined to be True, then
   all test methods in the TestCase will be guaranteed to run in a single process
   with the same instance. This is automatically set to True if your test class
   relies on setUpClass/tearDownClass.
 
   If the TestCase has a field `__expect_tests_atomic__` defined to be True, then
   in the event of a test filter which matches any test method in |test_case|,
   the ENTIRE |test_case| will be executed (i.e. the TestCase has interdependant
   test methods). This should only need to be set for very poorly designed tests.
 
   `__expect_tests_atomic__` implies `__expect_tests_serial__`.
 
   @type test_case: unittest.TestCase
   """
-  name_prefix = name_prefix + test_case.__name__
-  def _tests_from_class(cls, *args, **kwargs):
-    for test_name in unittest.defaultTestLoader.getTestCaseNames(cls):
-      yield Test(
-          name_prefix + '.' + test_name,
-          FuncCall(_RunTestCaseSingle, cls, test_name, *args, **kwargs),
-          ext=ext, break_funcs=[getattr(cls, test_name)],
+  @covers(lambda: Test.covers_obj(test_case))
+  def _inner():
+    name_prefix = '.'.join((test_case.__module__, test_case.__name__))
+
+    def _tests_from_class(cls, *args, **kwargs):
+      for test_name in unittest.defaultTestLoader.getTestCaseNames(cls):
+        yield Test(
+            name_prefix + '.' + test_name,
+            FuncCall(_RunTestCaseSingle, cls, test_name, *args, **kwargs),
+            expect_dir=Test.expect_dir_obj(cls),
+            expect_base=cls.__name__ + '.' + test_name,
+            break_funcs=[getattr(cls, test_name)],
+            covers=Test.covers_obj(cls)
+        )
+
+    if hasattr(test_case, '__expect_tests_serial__'):
+      serial = getattr(test_case, '__expect_tests_serial__', False)
+    else:
+      default_setup = unittest.TestCase.setUpClass.im_func
+      default_teardown = unittest.TestCase.tearDownClass.im_func
+      serial = (
+          test_case.setUpClass.im_func is not default_setup or
+          test_case.tearDownClass.im_func is not default_teardown)
+
+    atomic = getattr(test_case, '__expect_tests_atomic__', False)
+    if atomic or serial:
+      yield MultiTest(
+          name_prefix,
+          FuncCall(_SetUpClass, test_case),
+          FuncCall(_TearDownClass, Bind(name='context')),
+          list(_tests_from_class(test_case,
+                                 test_instance=Bind(name='context'))),
+          atomic
       )
-
-  if hasattr(test_case, '__expect_tests_serial__'):
-    serial = getattr(test_case, '__expect_tests_serial__', False)
-  else:
-    default_setup = unittest.TestCase.setUpClass.im_func
-    default_teardown = unittest.TestCase.tearDownClass.im_func
-    serial = (
-        test_case.setUpClass.im_func is not default_setup or
-        test_case.tearDownClass.im_func is not default_teardown)
-
-  atomic = getattr(test_case, '__expect_tests_atomic__', False)
-  if atomic or serial:
-    yield MultiTest(
-        name_prefix,
-        FuncCall(_SetUpClass, test_case),
-        FuncCall(_TearDownClass, Bind(name='context')),
-        list(_tests_from_class(test_case, test_instance=Bind(name='context'))),
-        atomic
-    )
-  else:
-    for test in _tests_from_class(test_case):
-      yield test
+    else:
+      for test in _tests_from_class(test_case):
+        yield test
+  return _inner
 
 
-def UnitTestModule(test_module, name_prefix='', ext='json'):
+def _is_unittest(obj):
+  return isinstance(obj, type) and issubclass(obj, unittest.TestCase)
+
+
+def UnitTestModule(test_module):
   """Yield MultiTest's and/or Test's for the python module |test_module| which
   contains zero or more unittest.TestCase implementations.
 
   @type test_module: types.ModuleType
   """
-  name_prefix = name_prefix + test_module.__name__ + '.'
   for name in dir(test_module):
     obj = getattr(test_module, name)
-    if isinstance(obj, type) and issubclass(obj, unittest.TestCase):
-      for test in UnittestTestCase(obj, name_prefix, ext):
+    if _is_unittest(obj):
+      for test in UnittestTestCase(obj)():
         yield test
     # TODO(iannucci): Make this compatible with the awful load_tests hack?