Split min_value/max_value field arguments to a base class and added them to DurationField.

PR fixes.

Python 2 fix.

Author: noamkush

docs/api-guide/fields.md

@@ -360,7 +360,10 @@ Corresponds to `django.db.models.fields.DurationField`
 The `validated_data` for these fields will contain a `datetime.timedelta` instance.
 The representation is a string following this format `'[DD] [HH:[MM:]]ss[.uuuuuu]'`.
 
-**Signature:** `DurationField()`
+**Signature:** `DurationField(max_value=None, min_value=None)`
+
+- `max_value` Validate that the duration provided is no greater than this value.
+- `min_value` Validate that the duration provided is no less than this value.
 
 ---
 

rest_framework/fields.py

@@ -903,20 +903,16 @@ def to_internal_value(self, data):
 
 # Number types...
 
-class IntegerField(Field):
+class MaxMinMixin(object):
     default_error_messages = {
-        'invalid': _('A valid integer is required.'),
         'max_value': _('Ensure this value is less than or equal to {max_value}.'),
         'min_value': _('Ensure this value is greater than or equal to {min_value}.'),
-        'max_string_length': _('String value too large.')
     }
-    MAX_STRING_LENGTH = 1000  # Guard against malicious string inputs.
-    re_decimal = re.compile(r'\.0*\s*$')  # allow e.g. '1.0' as an int, but not '1.2'
 
     def __init__(self, **kwargs):
         self.max_value = kwargs.pop('max_value', None)
         self.min_value = kwargs.pop('min_value', None)
-        super(IntegerField, self).__init__(**kwargs)
+        super(MaxMinMixin, self).__init__(**kwargs)
         if self.max_value is not None:
             message = lazy(
                 self.error_messages['max_value'].format,
@@ -930,6 +926,15 @@ def __init__(self, **kwargs):
             self.validators.append(
                 MinValueValidator(self.min_value, message=message))
 
+
+class IntegerField(MaxMinMixin, Field):
+    default_error_messages = {
+        'invalid': _('A valid integer is required.'),
+        'max_string_length': _('String value too large.')
+    }
+    MAX_STRING_LENGTH = 1000  # Guard against malicious string inputs.
+    re_decimal = re.compile(r'\.0*\s*$')  # allow e.g. '1.0' as an int, but not '1.2'
+
     def to_internal_value(self, data):
         if isinstance(data, six.text_type) and len(data) > self.MAX_STRING_LENGTH:
             self.fail('max_string_length')
@@ -944,32 +949,13 @@ def to_representation(self, value):
         return int(value)
 
 
-class FloatField(Field):
+class FloatField(MaxMinMixin, Field):
     default_error_messages = {
         'invalid': _('A valid number is required.'),
-        'max_value': _('Ensure this value is less than or equal to {max_value}.'),
-        'min_value': _('Ensure this value is greater than or equal to {min_value}.'),
         'max_string_length': _('String value too large.')
     }
     MAX_STRING_LENGTH = 1000  # Guard against malicious string inputs.
 
-    def __init__(self, **kwargs):
-        self.max_value = kwargs.pop('max_value', None)
-        self.min_value = kwargs.pop('min_value', None)
-        super(FloatField, self).__init__(**kwargs)
-        if self.max_value is not None:
-            message = lazy(
-                self.error_messages['max_value'].format,
-                six.text_type)(max_value=self.max_value)
-            self.validators.append(
-                MaxValueValidator(self.max_value, message=message))
-        if self.min_value is not None:
-            message = lazy(
-                self.error_messages['min_value'].format,
-                six.text_type)(min_value=self.min_value)
-            self.validators.append(
-                MinValueValidator(self.min_value, message=message))
-
     def to_internal_value(self, data):
 
         if isinstance(data, six.text_type) and len(data) > self.MAX_STRING_LENGTH:
@@ -984,11 +970,9 @@ def to_representation(self, value):
         return float(value)
 
 
-class DecimalField(Field):
+class DecimalField(MaxMinMixin, Field):
     default_error_messages = {
         'invalid': _('A valid number is required.'),
-        'max_value': _('Ensure this value is less than or equal to {max_value}.'),
-        'min_value': _('Ensure this value is greater than or equal to {min_value}.'),
         'max_digits': _('Ensure that there are no more than {max_digits} digits in total.'),
         'max_decimal_places': _('Ensure that there are no more than {max_decimal_places} decimal places.'),
         'max_whole_digits': _('Ensure that there are no more than {max_whole_digits} digits before the decimal point.'),
@@ -1006,28 +990,12 @@ def __init__(self, max_digits, decimal_places, coerce_to_string=None, max_value=
         if self.localize:
             self.coerce_to_string = True
 
-        self.max_value = max_value
-        self.min_value = min_value
-
         if self.max_digits is not None and self.decimal_places is not None:
             self.max_whole_digits = self.max_digits - self.decimal_places
         else:
             self.max_whole_digits = None
 
-        super(DecimalField, self).__init__(**kwargs)
-
-        if self.max_value is not None:
-            message = lazy(
-                self.error_messages['max_value'].format,
-                six.text_type)(max_value=self.max_value)
-            self.validators.append(
-                MaxValueValidator(self.max_value, message=message))
-        if self.min_value is not None:
-            message = lazy(
-                self.error_messages['min_value'].format,
-                six.text_type)(min_value=self.min_value)
-            self.validators.append(
-                MinValueValidator(self.min_value, message=message))
+        super(DecimalField, self).__init__(max_value=max_value, min_value=min_value, **kwargs)
 
         if rounding is not None:
             valid_roundings = [v for k, v in vars(decimal).items() if k.startswith('ROUND_')]
@@ -1351,7 +1319,7 @@ def to_representation(self, value):
         return value.strftime(output_format)
 
 
-class DurationField(Field):
+class DurationField(MaxMinMixin, Field):
     default_error_messages = {
         'invalid': _('Duration has wrong format. Use one of these formats instead: {format}.'),
     }

tests/test_fields.py

@@ -1401,6 +1401,23 @@ class TestNoOutputFormatTimeField(FieldValues):
     field = serializers.TimeField(format=None)
 
 
+class TestMinMaxDurationField(FieldValues):
+    """
+    Valid and invalid values for `IntegerField` with min and max limits.
+    """
+    valid_inputs = {
+        '3 08:32:01.000123': datetime.timedelta(days=3, hours=8, minutes=32, seconds=1, microseconds=123),
+        86401: datetime.timedelta(days=1, seconds=1),
+    }
+    invalid_inputs = {
+        3600: ['Ensure this value is greater than or equal to 1 day, 0:00:00.'],
+        '4 08:32:01.000123': ['Ensure this value is less than or equal to 4 days, 0:00:00.'],
+        '3600': ['Ensure this value is greater than or equal to 1 day, 0:00:00.'],
+    }
+    outputs = {}
+    field = serializers.DurationField(min_value=datetime.timedelta(days=1), max_value=datetime.timedelta(days=4))
+
+
 class TestDurationField(FieldValues):
     """
     Valid and invalid values for `DurationField`.