Merge branch 'feature/fix-float-rounding-precision-bug' into 'master'

Refactor precision calculation due to boundary float values

See merge request !43

schematics/types/custom.py

+import decimal
 import json
 
 import operator
@@ -54,9 +55,17 @@ class DecimalIntegerType(NumberType):
     def is_precision_valid(self, value):
         """
         Check if value has less than `strict` decimal numbers
-        works with numbers less than .9999999999996 decimal part
         """
-        return round(value * self.get_strict()) == round(value * self.get_strict(), 10)
+        try:
+            value = decimal.Decimal(str(value).strip())
+        except (TypeError, decimal.InvalidOperation):
+            raise ValidationError(
+                self.messages['number_coerce'].format(value, self.number_type.lower())
+            )
+        _, _, exponent = value.as_tuple()
+        if exponent <= 0:
+            return abs(exponent) <= self.strict
+        return True
 
     def validate_range(self, value, context=None):
         """

tests/custom_types/test_decimal_integer_type.py

@@ -133,7 +133,12 @@ class TestDecimalIntegerType:
         [-655.31, 2],
         [0.31, 2],
         [5 ** (10*100), 2],
-        [0.9999999999996, 2],
+        [1000.99999999999996, 2],  # float rounding cases
+        [100.999999999999996, 2],  # float rounding cases
+        [10.9999999999999996, 2],  # float rounding cases
+        [1.99999999999999996, 2],  # float rounding cases
+        [1999999999999999.96, 2],  # float rounding cases
+        [199999999999999.996, 2],  # float rounding cases
     ])
     def test_value_precision(self, value, strict):
         test_field = types.DecimalIntegerType(strict=strict)
@@ -147,16 +152,21 @@ class TestDecimalIntegerType:
         (10.1, 2, does_not_raise()),
         (10.001, 2, pytest.raises(exceptions.ValidationError)),
         (10.009, 2, pytest.raises(exceptions.ValidationError)),
+        (10.9999999, 2, pytest.raises(exceptions.ValidationError)),
         (10.9999999999, 2, pytest.raises(exceptions.ValidationError)),
         (10.9999999999995, 2, pytest.raises(exceptions.ValidationError)),
         (3.55, 2, does_not_raise()),
-        (3., 0, does_not_raise()),
-        (3.0, 0, does_not_raise()),
+        (3, 0, does_not_raise()),
+        (3., 0, pytest.raises(exceptions.ValidationError)),
+        (3.00000, 0, pytest.raises(exceptions.ValidationError)),
         (92.1, 2, does_not_raise()),
         (5 ** (10*100), 0, does_not_raise()),
         (-(5 ** (10*100)), 0, does_not_raise()),
-        (types.DecimalIntegerType._max_int, 0, does_not_raise()),
-        (-types.DecimalIntegerType._max_int, 0, does_not_raise()),
+        (-(5 ** (10*100)), 0, does_not_raise()),
+        (1234575889578.63, 2, does_not_raise()),
+        (1234575889578.91, 2, does_not_raise()),
+        (types.DecimalIntegerType._max_int/100, 2, does_not_raise()),
+        (-types.DecimalIntegerType._max_int/100, 2, does_not_raise()),
     ])
     def test_precision_validation(self, value, strict, expectation):
         test_field = types.DecimalIntegerType(strict=strict)