Remove formatted messages as parameters to field bound validators, fixes

 #3354

- Update tests to reflect new error messages provided by Django field
  parent classes

rest_framework/fields.py

@@ -675,11 +675,9 @@ def __init__(self, **kwargs):
         self.min_length = kwargs.pop('min_length', None)
         super(CharField, self).__init__(**kwargs)
         if self.max_length is not None:
-            message = self.error_messages['max_length'].format(max_length=self.max_length)
-            self.validators.append(MaxLengthValidator(self.max_length, message=message))
+            self.validators.append(MaxLengthValidator(self.max_length))
         if self.min_length is not None:
-            message = self.error_messages['min_length'].format(min_length=self.min_length)
-            self.validators.append(MinLengthValidator(self.min_length, message=message))
+            self.validators.append(MinLengthValidator(self.min_length))
 
     def run_validation(self, data=empty):
         # Test for the empty string here so that it does not get validated,
@@ -820,11 +818,9 @@ def __init__(self, **kwargs):
         self.min_value = kwargs.pop('min_value', None)
         super(IntegerField, self).__init__(**kwargs)
         if self.max_value is not None:
-            message = self.error_messages['max_value'].format(max_value=self.max_value)
-            self.validators.append(MaxValueValidator(self.max_value, message=message))
+            self.validators.append(MaxValueValidator(self.max_value))
         if self.min_value is not None:
-            message = self.error_messages['min_value'].format(min_value=self.min_value)
-            self.validators.append(MinValueValidator(self.min_value, message=message))
+            self.validators.append(MinValueValidator(self.min_value))
 
     def to_internal_value(self, data):
         if isinstance(data, six.text_type) and len(data) > self.MAX_STRING_LENGTH:
@@ -854,11 +850,9 @@ def __init__(self, **kwargs):
         self.min_value = kwargs.pop('min_value', None)
         super(FloatField, self).__init__(**kwargs)
         if self.max_value is not None:
-            message = self.error_messages['max_value'].format(max_value=self.max_value)
-            self.validators.append(MaxValueValidator(self.max_value, message=message))
+            self.validators.append(MaxValueValidator(self.max_value))
         if self.min_value is not None:
-            message = self.error_messages['min_value'].format(min_value=self.min_value)
-            self.validators.append(MinValueValidator(self.min_value, message=message))
+            self.validators.append(MinValueValidator(self.min_value))
 
     def to_internal_value(self, data):
         if isinstance(data, six.text_type) and len(data) > self.MAX_STRING_LENGTH:
@@ -903,11 +897,9 @@ def __init__(self, max_digits, decimal_places, coerce_to_string=None, max_value=
         super(DecimalField, self).__init__(**kwargs)
 
         if self.max_value is not None:
-            message = self.error_messages['max_value'].format(max_value=self.max_value)
-            self.validators.append(MaxValueValidator(self.max_value, message=message))
+            self.validators.append(MaxValueValidator(self.max_value))
         if self.min_value is not None:
-            message = self.error_messages['min_value'].format(min_value=self.min_value)
-            self.validators.append(MinValueValidator(self.min_value, message=message))
+            self.validators.append(MinValueValidator(self.min_value))
 
     def to_internal_value(self, data):
         """
@@ -1606,8 +1598,7 @@ def __init__(self, model_field, **kwargs):
         max_length = kwargs.pop('max_length', None)
         super(ModelField, self).__init__(**kwargs)
         if max_length is not None:
-            message = self.error_messages['max_length'].format(max_length=max_length)
-            self.validators.append(MaxLengthValidator(max_length, message=message))
+            self.validators.append(MaxLengthValidator(max_length))
 
     def to_internal_value(self, data):
         rel = getattr(self.model_field, 'rel', None)

tests/test_bound_fields.py

@@ -39,7 +39,7 @@ class ExampleSerializer(serializers.Serializer):
         serializer.is_valid()
 
         assert serializer['text'].value == 'x' * 1000
-        assert serializer['text'].errors == ['Ensure this field has no more than 100 characters.']
+        assert serializer['text'].errors == ['Ensure this value has at most 100 characters (it has 1000).']
         assert serializer['text'].name == 'text'
         assert serializer['amount'].value is 123
         assert serializer['amount'].errors is None

tests/test_generics.py

@@ -154,7 +154,7 @@ def test_post_error_root_view(self):
         data = {'text': 'foobar' * 100}
         request = factory.post('/', data, HTTP_ACCEPT='text/html')
         response = self.view(request).render()
-        expected_error = '<span class="help-block">Ensure this field has no more than 100 characters.</span>'
+        expected_error = '<span class="help-block">Ensure this value has at most 100 characters (it has 600).</span>'
         self.assertIn(expected_error, response.rendered_content.decode('utf-8'))
 
 
@@ -301,7 +301,7 @@ def test_put_error_instance_view(self):
         data = {'text': 'foobar' * 100}
         request = factory.put('/', data, HTTP_ACCEPT='text/html')
         response = self.view(request, pk=1).render()
-        expected_error = '<span class="help-block">Ensure this field has no more than 100 characters.</span>'
+        expected_error = '<span class="help-block">Ensure this value has at most 100 characters (it has 600).</span>'
         self.assertIn(expected_error, response.rendered_content.decode('utf-8'))