from decimal import Decimal from django.core import validators from django.core.exceptions import ValidationError from django.db import models from django.test import TestCase from .models import BigD, Foo class DecimalFieldTests(TestCase): def test_to_python(self): f = models.DecimalField(max_digits=4, decimal_places=2) self.assertEqual(f.to_python(3), Decimal('3')) self.assertEqual(f.to_python('3.14'), Decimal('3.14')) # to_python() converts floats and honors max_digits. self.assertEqual(f.to_python(3.1415926535897), Decimal('3.142')) self.assertEqual(f.to_python(2.4), Decimal('2.400')) # Uses default rounding of ROUND_HALF_EVEN. self.assertEqual(f.to_python(2.0625), Decimal('2.062')) self.assertEqual(f.to_python(2.1875), Decimal('2.188')) def test_invalid_value(self): field = models.DecimalField(max_digits=4, decimal_places=2) msg = 'ā€œ%sā€ value must be a decimal number.' tests = [ (), [], {}, set(), object(), complex(), 'non-numeric string', b'non-numeric byte-string', ] for value in tests: with self.subTest(value): with self.assertRaisesMessage(ValidationError, msg % (value,)): field.clean(value, None) def test_default(self): f = models.DecimalField(default=Decimal('0.00')) self.assertEqual(f.get_default(), Decimal('0.00')) def test_get_prep_value(self): f = models.DecimalField(max_digits=5, decimal_places=1) self.assertIsNone(f.get_prep_value(None)) self.assertEqual(f.get_prep_value('2.4'), Decimal('2.4')) def test_filter_with_strings(self): """ Should be able to filter decimal fields using strings (#8023). """ foo = Foo.objects.create(a='abc', d=Decimal('12.34')) self.assertEqual(list(Foo.objects.filter(d='12.34')), [foo]) def test_save_without_float_conversion(self): """ Ensure decimals don't go through a corrupting float conversion during save (#5079). """ bd = BigD(d='12.9') bd.save() bd = BigD.objects.get(pk=bd.pk) self.assertEqual(bd.d, Decimal('12.9')) def test_fetch_from_db_without_float_rounding(self): big_decimal = BigD.objects.create(d=Decimal('.100000000000000000000000000005')) big_decimal.refresh_from_db() self.assertEqual(big_decimal.d, Decimal('.100000000000000000000000000005')) def test_lookup_really_big_value(self): """ Really big values can be used in a filter statement. """ # This should not crash. Foo.objects.filter(d__gte=100000000000) def test_max_digits_validation(self): field = models.DecimalField(max_digits=2) expected_message = validators.DecimalValidator.messages['max_digits'] % {'max': 2} with self.assertRaisesMessage(ValidationError, expected_message): field.clean(100, None) def test_max_decimal_places_validation(self): field = models.DecimalField(decimal_places=1) expected_message = validators.DecimalValidator.messages['max_decimal_places'] % {'max': 1} with self.assertRaisesMessage(ValidationError, expected_message): field.clean(Decimal('0.99'), None) def test_max_whole_digits_validation(self): field = models.DecimalField(max_digits=3, decimal_places=1) expected_message = validators.DecimalValidator.messages['max_whole_digits'] % {'max': 2} with self.assertRaisesMessage(ValidationError, expected_message): field.clean(Decimal('999'), None) def test_roundtrip_with_trailing_zeros(self): """Trailing zeros in the fractional part aren't truncated.""" obj = Foo.objects.create(a='bar', d=Decimal('8.320')) obj.refresh_from_db() self.assertEqual(obj.d.compare_total(Decimal('8.320')), Decimal('0'))