Added MockerTestCase.assertMethodsMatch(). It will verify if all

public methods found in the class passed as the first argument are
also present in the class passed as the second argument, and that
they accept the same arguments.  This is useful to verify if a fake
or stub class have the same API as the real class being simulated.

1 files changed, 34 insertions, 0 deletions

diff --git a/mocker.py b/mocker.py
index fe27892..7d7160c 100644
--- a/mocker.py
+++ b/mocker.py
@@ -192,12 +192,46 @@ class MockerTestCase(unittest.TestCase):
             raise self.failureException(msg or "abs(%r - %r) <= %r" %
                                         (first, second, tolerance))
 
+    def failUnlessMethodsMatch(self, first, second):
+        """Assert that public methods in C{first} are present in C{second}.
+
+        This method asserts that all public methods found in C{first} are also
+        present in C{second} and accept the same arguments.  C{first} may
+        have its own private methods, though, and may not have all methods
+        found in C{second}.  Note that if a private method in C{first} matches
+        the name of one in C{second}, their specification is still compared.
+
+        This is useful to verify if a fake or stub class have the same API as
+        the real class being simulated.
+        """
+        first_methods = dict(inspect.getmembers(first, inspect.ismethod))
+        second_methods = dict(inspect.getmembers(second, inspect.ismethod))
+        for name, first_method in first_methods.items():
+            first_argspec = inspect.getargspec(first_method)
+            first_formatted = inspect.formatargspec(*first_argspec)
+
+            second_method = second_methods.get(name)
+            if second_method is None:
+                if name[:1] == "_":
+                    continue # First may have its own private methods.
+                raise self.failureException("%s.%s%s not present in %s" %
+                    (first.__name__, name, first_formatted, second.__name__))
+
+            second_argspec = inspect.getargspec(second_method)
+            if first_argspec != second_argspec:
+                second_formatted = inspect.formatargspec(*second_argspec)
+                raise self.failureException("%s.%s%s != %s.%s%s" %
+                    (first.__name__, name, first_formatted,
+                     second.__name__, name, second_formatted))
+
+
     assertIs = failUnlessIs
     assertIsNot = failIfIs
     assertIn = failUnlessIn
     assertNotIn = failIfIn
     assertApproximates = failUnlessApproximates
     assertNotApproximates = failIfApproximates
+    assertMethodsMatch = failUnlessMethodsMatch
 
     # The following is provided for compatibility with Twisted's trial.
     assertIdentical = assertIs