Use unicode message if regex is also unicode in ExceptionInfo.match

src/_pytest/_code/code.py

@@ -572,9 +572,13 @@ class ExceptionInfo(object):
         raised.
         """
         __tracebackhide__ = True
-        value = safe_str(self.value)
+        value = (
+            text_type(self.value) if isinstance(regexp, text_type) else str(self.value)
+        )
         if not re.search(regexp, value):
-            assert 0, "Pattern '{!s}' not found in '{!s}'".format(regexp, value)
+            raise AssertionError(
+                "Pattern '{!s}' not found in '{!s}'".format(regexp, value)
+            )
         return True
 
 

testing/python/raises.py

@@ -279,6 +279,8 @@ class TestRaises(object):
                     pass
             assert "via __class__" in excinfo.value.args[0]
 
-    def test_u(self):
+    def test_unicode_message(self):
+        """pytest.raises should be able to match unicode messages when using a unicode regex (#5478)
+        """
         with pytest.raises(AssertionError, match=u"\u2603"):
             assert False, u"\u2603"