Handle pass-through assertion methods that are just forwarding parameters

docs/changelog.rst

@@ -2,6 +2,7 @@
 Changelog
 =========
 
+* :bug:`85` Fixed marbles handling of deprecated assertEquals and similar methods
 * :release:`0.9.5 <2018-06-24>`
 * :support:`80` Added support for ``pandas<0.24``
 * :bug:`58` Fixed test failure on OSX

marbles/core/marbles/core/marbles.py

@@ -432,9 +432,19 @@ def _find_msg_argument(signature):
         The index of the ``msg`` param, the default value for it,
         and the number of non-``msg`` positional parameters we expect.
     '''
-    names = signature.parameters.keys()
+    names = list(signature.parameters.keys())
+    if len(names) == 2:
+        param_kinds = [signature.parameters[name].kind for name in names]
+        if (param_kinds[0] == inspect.Parameter.VAR_POSITIONAL
+                and param_kinds[1] == inspect.Parameter.VAR_KEYWORD):
+            # This is likely an assertion wrapper like
+            # assertEquals(*args, **kwargs), in which case we should
+            # just forward the arguments along and catch them in the
+            # wrapped assertion method (see
+            # https://github.com/twosigma/marbles/issue/85).
+            return sys.maxsize, None, len(names)
     try:
-        msg_idx = list(names).index('msg')
+        msg_idx = names.index('msg')
         default_msg = signature.parameters['msg'].default
     except ValueError:  # 'msg' is not in list
         # It's likely that this is a custom assertion that's just

marbles/core/tests/test_marbles.py

@@ -82,6 +82,26 @@ def test_success(self):
     def test_failure(self):
         self.assertTrue(False, note='some note')
 
+    def test_deprecated_assertEquals_success(self):
+        x = 1
+        y = 1
+        self.assertEquals(x, y)
+
+    def test_deprecated_assertEquals_failure(self):
+        x = 1
+        y = 2
+        self.assertEquals(x, y)
+
+    def test_deprecated_assertEquals_success_with_note(self):
+        x = 1
+        y = 1
+        self.assertEquals(x, y, note='x should equal y')
+
+    def test_deprecated_assertEquals_failure_with_note(self):
+        x = 1
+        y = 2
+        self.assertEquals(x, y, note='x should equal y')
+
     def test_fail_without_msg_without_note(self):
         self.fail()
 
@@ -345,6 +365,29 @@ def test_annotated_assertion_error_raised(self):
         with self.assertRaises(ContextualAssertionError):
             self.case.test_failure()
 
+    def test_deprecated_assertEquals_success(self):
+        '''Does the deprecated assertEquals method still work?'''
+        if self._use_annotated_test_case:
+            with self.assertRaises(AnnotationError):
+                self.case.test_deprecated_assertEquals_success()
+            self.case.test_deprecated_assertEquals_success_with_note()
+        else:
+            self.case.test_deprecated_assertEquals_success()
+            self.case.test_deprecated_assertEquals_success_with_note()
+
+    def test_deprecated_assertEquals_failure(self):
+        '''Does the deprecated assertEquals method work on failure?'''
+        if self._use_annotated_test_case:
+            with self.assertRaises(AnnotationError):
+                self.case.test_deprecated_assertEquals_failure()
+            with self.assertRaises(ContextualAssertionError):
+                self.case.test_deprecated_assertEquals_failure_with_note()
+        else:
+            with self.assertRaises(ContextualAssertionError):
+                self.case.test_deprecated_assertEquals_failure()
+            with self.assertRaises(ContextualAssertionError):
+                self.case.test_deprecated_assertEquals_failure_with_note()
+
     def test_fail_handles_note_properly(self):
         '''Does TestCase.fail() deal with note the right way?'''
         if self._use_annotated_test_case:
@@ -515,7 +558,7 @@ def test_get_stack(self):
         self.assertEqual(e.filename, os.path.abspath(__file__))
         # This isn't great because I have to change it every time I
         # add/remove imports but oh well
-        self.assertEqual(e.linenumber, 211)
+        self.assertEqual(e.linenumber, 231)
 
     def test_assert_stmt_indicates_line(self):
         '''Does e.assert_stmt indicate the line from the source code?'''