Add a utility class that makes it easy to use strict/nice mocks.

The idea is to formalize the friending/named constructor patterns
used in the existing mocks, and extend them to support creating
nice and strict mocks in addition to the default ones.

I have deliberately changed the default mock constructor
from create() to create_default(); I want it to be explicit
which variant is being used, and I also want existing code
to fail so I can update it.  Strict mocks should really be
the default in most cases.

3 files changed, 95 insertions, 2 deletions

diff --git a/src/generic/util/mocks/Makefile.am b/src/generic/util/mocks/Makefile.am
index 6b88c48d..67c8ed5f 100644
--- a/src/generic/util/mocks/Makefile.am
+++ b/src/generic/util/mocks/Makefile.am
@@ -1 +1 @@
-EXTRA_DIST = throttle.h
\ No newline at end of file
+EXTRA_DIST = mock_util.h throttle.h
\ No newline at end of file
diff --git a/src/generic/util/mocks/SConscript b/src/generic/util/mocks/SConscript
index 025e0f15..fffd9451 100644
--- a/src/generic/util/mocks/SConscript
+++ b/src/generic/util/mocks/SConscript
@@ -1,3 +1,3 @@
 Import('programs_env')
 
-programs_env.Dist('throttle.h')
+programs_env.Dist('mock_util.h', 'throttle.h')
diff --git a/src/generic/util/mocks/mock_util.h b/src/generic/util/mocks/mock_util.h
new file mode 100644
index 00000000..e8cf4d9e
--- /dev/null
+++ b/src/generic/util/mocks/mock_util.h
@@ -0,0 +1,93 @@
+// \file mock_util.h            -*-c++-*-
+//
+// Copyright (C) 2010 Daniel Burrows
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of the
+// License, or (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful, but
+// WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program; see the file COPYING.  If not, write to
+// the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+// Boston, MA 02111-1307, USA.
+
+#ifndef APTITUDE_GENERIC_MOCK_UTIL_H
+#define APTITUDE_GENERIC_MOCK_UTIL_H
+
+// System includes:
+#include <boost/make_shared.hpp>
+#include <boost/shared_ptr.hpp>
+
+#include <gmock/gmock.h>
+
+namespace aptitude
+{
+  namespace util
+  {
+    namespace mocks
+    {
+      /** \brief Convenience mixin that instruments a mock class with
+       *  a standard set of static constructors: one for nice mocks,
+       *  one for default mocks, and one for strict mocks.
+       *
+       *  \tparam SubMockType The class to instrument; must be a subclass
+       *  of this class.  Must be default-constructable.
+       *
+       *  If the constructor of MockType is hidden, then
+       *  NiceMock<MockType> and StrictMock<MockType> must be friends
+       *  of Mock (so that they can subclass it).  See MOCK_FRIENDS()
+       *  for a convenient way to declare this.
+       */
+      template<typename SubMockType>
+      class Mock
+      {
+      public:
+        virtual ~Mock()
+        {
+        }
+
+        typedef SubMockType MockType;
+        typedef testing::NiceMock<MockType> NiceMockType;
+        typedef testing::StrictMock<MockType> StrictMockType;
+
+        /** \brief Create a default-style mock. */
+        static boost::shared_ptr<MockType> create_default()
+        {
+          return boost::make_shared<MockType>();
+        }
+
+        /** \brief Create a nice mock. */
+        static boost::shared_ptr<MockType> create_nice()
+        {
+          return boost::make_shared<NiceMockType>();
+        }
+
+        /** \brief Create a strict mock. */
+        static boost::shared_ptr<MockType> create_strict()
+        {
+          return boost::make_shared<StrictMockType>();
+        }
+      };
+
+      /** \brief Convenience macro to support mocks with hidden
+       *  constructors.
+       *
+       *  This expands to the friend declarations that are required
+       *  for Mock to function.  It must be invoked in the class body
+       *  of a subclass of Mock that does not declare the name
+       *  MockType.
+       */
+#define MOCK_FRIENDS()                                  \
+      friend class testing::NiceMock<MockType>;         \
+      friend class testing::StrictMock<MockType>;
+    }
+  }
+}
+
+#endif // APTITUDE_GENERIC_MOCK_UTIL_H