# HG changeset patch
# Parent eb392fcc6177d30e32f8e0c9a02dd8697800d796
# User Julien Pagès <j.parkouss@gmail.com>
add a TestCase.patch method

diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
--- a/Doc/library/unittest.rst
+++ b/Doc/library/unittest.rst
@@ -753,16 +753,37 @@ Test cases
       A test case can contain any number of subtest declarations, and
       they can be arbitrarily nested.
 
       See :ref:`subtests` for more information.
 
       .. versionadded:: 3.4
 
 
+   .. method:: patch(*args, **kargs)
+
+      Convenience method that calls :func:`unittest.mock.patch` and returns the
+      mock instance used as the patch.
+
+      Example of use::
+
+          import platform
+
+          class TestCase(unittest.TestCase):
+              def setUp(self):
+                  self.patch('platform.system', return_value='PatchedLinux')
+
+              def test_patched(self):
+                  self.assertEqual(platform.system(), 'PatchedLinux')
+
+      Note that the patch will automatically be removed with :meth:`doCleanups`.
+
+      .. versionadded:: 3.5
+
+
    .. method:: debug()
 
       Run the test without collecting the result.  This allows exceptions raised
       by the test to be propagated to the caller, and can be used to support
       running tests under a debugger.
 
    .. _assert-methods:
 
diff --git a/Lib/unittest/case.py b/Lib/unittest/case.py
--- a/Lib/unittest/case.py
+++ b/Lib/unittest/case.py
@@ -628,16 +628,24 @@ class TestCase(object):
         """Run the test without collecting errors in a TestResult"""
         self.setUp()
         getattr(self, self._testMethodName)()
         self.tearDown()
         while self._cleanups:
             function, args, kwargs = self._cleanups.pop(-1)
             function(*args, **kwargs)
 
+    def patch(self, *args, **kwargs):
+        # lazy import
+        from unittest.mock import patch
+        p = patch(*args, **kwargs)
+        result = p.start()
+        self.addCleanup(p.stop)
+        return result
+
     def skipTest(self, reason):
         """Skip this test."""
         raise SkipTest(reason)
 
     def fail(self, msg=None):
         """Fail immediately, with the given message."""
         raise self.failureException(msg)
 
diff --git a/Lib/unittest/test/test_case.py b/Lib/unittest/test/test_case.py
--- a/Lib/unittest/test/test_case.py
+++ b/Lib/unittest/test/test_case.py
@@ -1564,11 +1564,27 @@ test case
             def test2(self):
                 raise MyException()
 
         for method_name in ('test1', 'test2'):
             testcase = TestCase(method_name)
             testcase.run()
             self.assertEqual(MyException.ninstance, 0)
 
+    @staticmethod
+    def to_be_patched():
+        return 1
+
+    def test_patch(self):
+        patch_name = __name__ + '.' + self.__class__.__name__ + '.to_be_patched'
+        class TestCase(unittest.TestCase):
+            def setUp(self):
+                self.patch(patch_name, return_value=2)
+
+        testcase = TestCase()
+        self.assertEqual(self.to_be_patched(), 1)
+        testcase.setUp()
+        self.assertEqual(self.to_be_patched(), 2)
+        testcase.doCleanups()
+        self.assertEqual(self.to_be_patched(), 1)
 
 if __name__ == "__main__":
     unittest.main()