Fixes #653 use deprecated_call as context_manager

Author: chiller

AUTHORS

@@ -28,6 +28,7 @@ Dave Hunt
 David Mohr
 Edison Gustavo Muenz
 Eduardo Schettino
+Endre Galaczi
 Elizaveta Shashkova
 Eric Hunsberger
 Eric Siegerman

CHANGELOG

@@ -6,6 +6,7 @@
 
 - Fix issue #411: Add __eq__ method to assertion comparison example.
   Thanks Ben Webb.
+- Fix issue #653: deprecated_call can be used as context manager.
 
 2.8.0
 -----------------------------

_pytest/recwarn.py

@@ -28,9 +28,18 @@ def pytest_namespace():
             'warns': warns}
 
 
-def deprecated_call(func, *args, **kwargs):
+def deprecated_call(func=None, *args, **kwargs):
     """Assert that ``func(*args, **kwargs)`` triggers a DeprecationWarning.
+
+    This function can be used as a context manager::
+
+        >>> with deprecated_call():
+        ...    myobject.deprecated_method()
     """
+    if not func:
+        warnings.simplefilter('always')
+        return WarningsChecker(expected_warning=DeprecationWarning)
+
     wrec = WarningsRecorder()
     with wrec:
         warnings.simplefilter('always')  # ensure all warnings are triggered

doc/en/recwarn.rst

@@ -114,3 +114,9 @@ command ``warnings.simplefilter('always')``::
         warnings.warn("deprecated", DeprecationWarning)
         assert len(recwarn) == 1
         assert recwarn.pop(DeprecationWarning)
+
+You can also use it as a contextmanager::
+
+    def test_global():
+        with pytest.deprecated_call():
+            myobject.deprecated_method()

testing/test_recwarn.py

@@ -79,6 +79,7 @@ def dep_explicit(i):
                                       filename="hello", lineno=3)
 
 class TestDeprecatedCall(object):
+
     def test_deprecated_call_raises(self):
         excinfo = pytest.raises(AssertionError,
                        "pytest.deprecated_call(dep, 3)")
@@ -111,6 +112,16 @@ def test_deprecated_explicit_call(self):
         pytest.deprecated_call(dep_explicit, 0)
         pytest.deprecated_call(dep_explicit, 0)
 
+    def test_deprecated_call_as_context_manager_no_warning(self):
+        with pytest.raises(pytest.fail.Exception) as ex:
+            with pytest.deprecated_call():
+                dep(1)
+        assert str(ex.value) == "DID NOT WARN"
+
+    def test_deprecated_call_as_context_manager(self):
+        with pytest.deprecated_call():
+            dep(0)
+
 
 class TestWarns(object):
     def test_strings(self):