Better error message for additionalProperties: false when there are patternProperties.

jsonschema/_validators.py

@@ -29,8 +29,18 @@ def additionalProperties(validator, aP, instance, schema):
             for error in validator.descend(instance[extra], aP, path=extra):
                 yield error
     elif not aP and extras:
-        error = "Additional properties are not allowed (%s %s unexpected)"
-        yield ValidationError(error % _utils.extras_msg(extras))
+        if "patternProperties" in schema:
+            patterns = sorted(schema["patternProperties"].keys())
+            if len(extras) == 1:
+                verb = "does"
+            else:
+                verb = "do"
+            error = "%s %s not match any of the regexs: %s" % (
+                ", ".join(map(repr, sorted(extras))), verb, ", ".join(patterns))
+            yield ValidationError(error)
+        else:
+            error = "Additional properties are not allowed (%s %s unexpected)"
+            yield ValidationError(error % _utils.extras_msg(extras))
 
 
 def items(validator, items, instance, schema):

jsonschema/tests/test_validators.py

@@ -191,6 +191,26 @@ class TestValidationErrorMessages(unittest.TestCase):
         self.assertIn(repr("thing"), message)
         self.assertIn("is not a", message)
 
+    def test_additionalProperties_false_patternProperties(self):
+        schema = {u"type": u"object",
+                  u"additionalProperties": False,
+                  u"patternProperties": {
+                      u"$abc^": {u"type": u"string"},
+                      u"$def^": {u"type": u"string"}
+                  }}
+        message = self.message_for({u"zebra": 123}, schema,
+                                   cls=Draft4Validator)
+        self.assertEqual(
+            message,
+            "{} does not match any of the regexs: $abc^, $def^".format(
+                repr(u"zebra")))
+        message = self.message_for({u"zebra": 123, u"fish": 456}, schema,
+                                   cls=Draft4Validator)
+        self.assertEqual(
+            message,
+            "{}, {} do not match any of the regexs: $abc^, $def^".format(
+                repr(u"fish"), repr(u"zebra")))
+
 
 class TestValidationErrorDetails(unittest.TestCase):
     # TODO: These really need unit tests for each individual validator, rather