Remove "matching '...'" part from the pytest.raises message

_pytest/python_api.py

@@ -571,7 +571,6 @@ def raises(expected_exception, *args, **kwargs):
             message = kwargs.pop("message")
         if "match" in kwargs:
             match_expr = kwargs.pop("match")
-            message += " matching '{0}'".format(match_expr)
         return RaisesContext(expected_exception, message, match_expr)
     elif isinstance(args[0], str):
         code, = args
@@ -618,6 +617,6 @@ def __exit__(self, *tp):
         suppress_exception = issubclass(self.excinfo.type, self.expected_exception)
         if sys.version_info[0] == 2 and suppress_exception:
             sys.exc_clear()
-        if self.match_expr:
+        if self.match_expr and suppress_exception:
             self.excinfo.match(self.match_expr)
         return suppress_exception

changelog/3222.bugfix

@@ -0,0 +1 @@
+Errors shown when a ``pytest.raises()`` with ``match=`` fails are now cleaner on what happened: When no exception was raised, the "matching '...'" part got removed as it falsely implies that an exception was raised but it didn't match. When a wrong exception was raised, it's now thrown (like ``pytest.raised()`` without ``match=`` would) instead of complaining about the unmatched text.

testing/python/raises.py

@@ -132,3 +132,13 @@ def test_raises_match(self):
         with pytest.raises(AssertionError, match=expr):
             with pytest.raises(ValueError, match=msg):
                 int('asdf', base=10)
+
+    def test_raises_match_wrong_type(self):
+        """Raising an exception with the wrong type and match= given.
+
+        pytest should throw the unexpected exception - the pattern match is not
+        really relevant if we got a different exception.
+        """
+        with pytest.raises(ValueError):
+            with pytest.raises(IndexError, match='nomatch'):
+                int('asdf')