Merge 6d3d82ae54 into 565c722762

rest_framework/fields.py

@@ -997,7 +997,7 @@ class DecimalField(Field):
     MAX_STRING_LENGTH = 1000  # Guard against malicious string inputs.
 
     def __init__(self, max_digits, decimal_places, coerce_to_string=None, max_value=None, min_value=None,
-                 localize=False, **kwargs):
+                 localize=False, rounding=None, **kwargs):
         self.max_digits = max_digits
         self.decimal_places = decimal_places
         self.localize = localize
@@ -1029,6 +1029,12 @@ class DecimalField(Field):
             self.validators.append(
                 MinValueValidator(self.min_value, message=message))
 
+        if rounding is not None:
+            valid_roundings = [v for k, v in vars(decimal).items() if k.startswith('ROUND_')]
+            assert rounding in valid_roundings, (
+                'Invalid rounding option %s. Valid values for rounding are: %s' % (rounding, valid_roundings))
+        self.rounding = rounding
+
     def to_internal_value(self, data):
         """
         Validate that the input is a decimal number and return a Decimal
@@ -1121,6 +1127,7 @@ class DecimalField(Field):
             context.prec = self.max_digits
         return value.quantize(
             decimal.Decimal('.1') ** self.decimal_places,
+            rounding=self.rounding,
             context=context
         )
 

tests/test_fields.py

@@ -1092,6 +1092,22 @@ class TestNoDecimalPlaces(FieldValues):
     field = serializers.DecimalField(max_digits=6, decimal_places=None)
 
 
+class TestRoundingDecimalField(TestCase):
+    def test_valid_rounding(self):
+        field = serializers.DecimalField(max_digits=4, decimal_places=2, rounding='ROUND_UP')
+        assert field.to_representation(Decimal('1.234')) == '1.24'
+
+        field = serializers.DecimalField(max_digits=4, decimal_places=2, rounding='ROUND_DOWN')
+        assert field.to_representation(Decimal('1.234')) == '1.23'
+
+    def test_invalid_rounding(self):
+        with pytest.raises(AssertionError) as excinfo:
+            serializers.DecimalField(max_digits=1, decimal_places=1, rounding='ROUND_UNKNOWN')
+        assert 'Invalid rounding option' in str(excinfo.value)
+
+
+
+
 # Date & time serializers...
 
 class TestDateField(FieldValues):