Allow to decorate class with mock

Now it is possible to mock not only a function but also a class:

  class TestClass(object)

    def test_func_a(self, m):
      m.register_uri('GET', 'http://test.com', text='data')
      ...

    def test_func_b(self, m)
      m.register_uri('GET', 'http://test.com', text='data')
      ...

This new behavior mimics behavior of `patch` from `mock` library.
Added docs for this new feature.

Closes-Bug: #1404805
Change-Id: I8303dc4bc682cf12ffe86e7712b5a1c54de83efb

docs/mocker.rst

@@ -47,6 +47,37 @@ If the position of the mock is likely to conflict with other arguments you can p
     >>> test_kw_function()
     'resp'
 
+Class Decorator
+===============
+
+Mocker can also be used to decorate a whole class. It works exactly like in case of decorating a normal function.
+When used in this way they wrap every test method on the class. The mocker recognise methods that start with *test* as being test methods.
+This is the same way that the `unittest.TestLoader` finds test methods by default.
+It is possible that you want to use a different prefix for your tests. You can inform the mocker of the different prefix by setting `requests_mock.Mocker.TEST_PREFIX`:
+
+.. doctest::
+
+    >>> requests_mock.Mocker.TEST_PREFIX = 'foo'
+    >>>
+    >>> @requests_mock.Mocker()
+    ... class Thing(object):
+    ...     def foo_one(self, m):
+    ...        m.register_uri('GET', 'http://test.com', text='resp')
+    ...        return requests.get('http://test.com').text
+    ...     def foo_two(self, m):
+    ...         m.register_uri('GET', 'http://test.com', text='resp')
+    ...         return requests.get('http://test.com').text
+    ...
+    >>>
+    >>> Thing().foo_one()
+    'resp'
+    >>> Thing().foo_two()
+    'resp'
+
+
+This behavior mimics how patchers from `mock` library works.
+
+
 Methods
 =======
 

requests_mock/mocker.py

@@ -123,6 +123,10 @@ class MockerCore(object):
 class Mocker(MockerCore):
     """The standard entry point for mock Adapter loading.
     """
+
+    #: Defines with what should method name begin to be patched
+    TEST_PREFIX = 'test'
+
     def __init__(self, **kwargs):
         """Create a new mocker adapter.
 
@@ -141,7 +145,26 @@ class Mocker(MockerCore):
     def __exit__(self, type, value, traceback):
         self.stop()
 
-    def __call__(self, func):
+    def __call__(self, obj):
+        if isinstance(obj, type):
+            return self.decorate_class(obj)
+
+        return self.decorate_callable(obj)
+
+    def copy(self):
+        """Returns an exact copy of current mock
+        """
+        m = Mocker(
+            kw=self._kw,
+            real_http=self._real_http
+        )
+        return m
+
+    def decorate_callable(self, func):
+        """Decorates a callable
+
+        :param callable func: callable to decorate
+        """
         @functools.wraps(func)
         def inner(*args, **kwargs):
             with self as m:
@@ -155,5 +178,25 @@ class Mocker(MockerCore):
 
         return inner
 
+    def decorate_class(self, klass):
+        """Decorates methods in a class with request_mock
+
+        Method will be decorated only if it name begins with `TEST_PREFIX`
+
+        :param object klass: class which methods will be decorated
+        """
+        for attr_name in dir(klass):
+            if not attr_name.startswith(self.TEST_PREFIX):
+                continue
+
+            attr = getattr(klass, attr_name)
+            if not hasattr(attr, '__call__'):
+                continue
+
+            m = self.copy()
+            setattr(klass, attr_name, m(attr))
+
+        return klass
+
 
 mock = Mocker

requests_mock/tests/test_mocker.py

@@ -88,6 +88,70 @@ class MockerTests(base.TestCase):
         inner()
         self.assertMockStopped()
 
+    def test_with_class_decorator(self):
+        outer = self
+
+        @requests_mock.mock()
+        class Decorated(object):
+
+            def test_will_be_decorated(self, m):
+                outer.assertMockStarted()
+                outer._do_test(m)
+
+            def will_not_be_decorated(self):
+                outer.assertMockStopped()
+
+        decorated_class = Decorated()
+
+        self.assertMockStopped()
+        decorated_class.test_will_be_decorated()
+        self.assertMockStopped()
+        decorated_class.will_not_be_decorated()
+        self.assertMockStopped()
+
+    def test_with_class_decorator_and_custom_kw(self):
+        outer = self
+
+        @requests_mock.mock(kw='custom_m')
+        class Decorated(object):
+
+            def test_will_be_decorated(self, **kwargs):
+                outer.assertMockStarted()
+                outer._do_test(kwargs['custom_m'])
+
+            def will_not_be_decorated(self):
+                outer.assertMockStopped()
+
+        decorated_class = Decorated()
+
+        self.assertMockStopped()
+        decorated_class.test_will_be_decorated()
+        self.assertMockStopped()
+        decorated_class.will_not_be_decorated()
+        self.assertMockStopped()
+
+    @mock.patch.object(requests_mock.mock, 'TEST_PREFIX', 'foo')
+    def test_with_class_decorator_and_custom_test_prefix(self):
+        outer = self
+
+        @requests_mock.mock()
+        class Decorated(object):
+
+            def foo_will_be_decorated(self, m):
+                outer.assertMockStarted()
+                outer._do_test(m)
+
+            def will_not_be_decorated(self):
+                outer.assertMockStopped()
+
+        decorated_class = Decorated()
+
+        self.assertMockStopped()
+        decorated_class.foo_will_be_decorated()
+        self.assertMockStopped()
+        decorated_class.will_not_be_decorated()
+        self.assertMockStopped()
+
     @requests_mock.mock()
     def test_query_string(self, m):
         url = 'http://test.url/path'
@@ -114,6 +178,13 @@ class MockerTests(base.TestCase):
         self.assertEqual(m.request_history, matcher.request_history)
         self.assertIs(m.last_request, matcher.last_request)
 
+    def test_copy(self):
+        mocker = requests_mock.mock(kw='foo', real_http=True)
+        copy_of_mocker = mocker.copy()
+        self.assertIsNot(copy_of_mocker, mocker)
+        self.assertEqual(copy_of_mocker._kw, mocker._kw)
+        self.assertEqual(copy_of_mocker._real_http, mocker._real_http)
+
 
 class MockerHttpMethodsTests(base.TestCase):