django/tests/utils_tests/test_numberformat.py

from decimal import Decimal
from sys import float_info

from django.test import SimpleTestCase
from django.utils.numberformat import format as nformat


class TestNumberFormat(SimpleTestCase):
    def test_format_number(self):
        self.assertEqual(nformat(1234, "."), "1234")
        self.assertEqual(nformat(1234.2, "."), "1234.2")
        self.assertEqual(nformat(1234, ".", decimal_pos=2), "1234.00")
        self.assertEqual(nformat(1234, ".", grouping=2, thousand_sep=","), "1234")
        self.assertEqual(
            nformat(1234, ".", grouping=2, thousand_sep=",", force_grouping=True),
            "12,34",
        )
        self.assertEqual(nformat(-1234.33, ".", decimal_pos=1), "-1234.3")
        # The use_l10n parameter can force thousand grouping behavior.
        with self.settings(USE_THOUSAND_SEPARATOR=True):
            self.assertEqual(
                nformat(1234, ".", grouping=3, thousand_sep=",", use_l10n=False), "1234"
            )
            self.assertEqual(
                nformat(1234, ".", grouping=3, thousand_sep=",", use_l10n=True), "1,234"
            )

    def test_format_string(self):
        self.assertEqual(nformat("1234", "."), "1234")
        self.assertEqual(nformat("1234.2", "."), "1234.2")
        self.assertEqual(nformat("1234", ".", decimal_pos=2), "1234.00")
        self.assertEqual(nformat("1234", ".", grouping=2, thousand_sep=","), "1234")
        self.assertEqual(
            nformat("1234", ".", grouping=2, thousand_sep=",", force_grouping=True),
            "12,34",
        )
        self.assertEqual(nformat("-1234.33", ".", decimal_pos=1), "-1234.3")
        self.assertEqual(
            nformat(
                "10000", ".", grouping=3, thousand_sep="comma", force_grouping=True
            ),
            "10comma000",
        )

    def test_large_number(self):
        most_max = (
            "{}179769313486231570814527423731704356798070567525844996"
            "598917476803157260780028538760589558632766878171540458953"
            "514382464234321326889464182768467546703537516986049910576"
            "551282076245490090389328944075868508455133942304583236903"
            "222948165808559332123348274797826204144723168738177180919"
            "29988125040402618412485836{}"
        )
        most_max2 = (
            "{}35953862697246314162905484746340871359614113505168999"
            "31978349536063145215600570775211791172655337563430809179"
            "07028764928468642653778928365536935093407075033972099821"
            "15310256415249098018077865788815173701691026788460916647"
            "38064458963316171186642466965495956524082894463374763543"
            "61838599762500808052368249716736"
        )
        int_max = int(float_info.max)
        self.assertEqual(nformat(int_max, "."), most_max.format("", "8"))
        self.assertEqual(nformat(int_max + 1, "."), most_max.format("", "9"))
        self.assertEqual(nformat(int_max * 2, "."), most_max2.format(""))
        self.assertEqual(nformat(0 - int_max, "."), most_max.format("-", "8"))
        self.assertEqual(nformat(-1 - int_max, "."), most_max.format("-", "9"))
        self.assertEqual(nformat(-2 * int_max, "."), most_max2.format("-"))

    def test_float_numbers(self):
        tests = [
            (9e-10, 10, "0.0000000009"),
            (9e-19, 2, "0.00"),
            (0.00000000000099, 0, "0"),
            (0.00000000000099, 13, "0.0000000000009"),
            (1e16, None, "10000000000000000"),
            (1e16, 2, "10000000000000000.00"),
            # A float without a fractional part (3.) results in a ".0" when no
            # decimal_pos is given. Contrast that with the Decimal('3.') case
            # in test_decimal_numbers which doesn't return a fractional part.
            (3.0, None, "3.0"),
        ]
        for value, decimal_pos, expected_value in tests:
            with self.subTest(value=value, decimal_pos=decimal_pos):
                self.assertEqual(nformat(value, ".", decimal_pos), expected_value)
        # Thousand grouping behavior.
        self.assertEqual(
            nformat(1e16, ".", thousand_sep=",", grouping=3, force_grouping=True),
            "10,000,000,000,000,000",
        )
        self.assertEqual(
            nformat(
                1e16,
                ".",
                decimal_pos=2,
                thousand_sep=",",
                grouping=3,
                force_grouping=True,
            ),
            "10,000,000,000,000,000.00",
        )

    def test_decimal_numbers(self):
        self.assertEqual(nformat(Decimal("1234"), "."), "1234")
        self.assertEqual(nformat(Decimal("1234.2"), "."), "1234.2")
        self.assertEqual(nformat(Decimal("1234"), ".", decimal_pos=2), "1234.00")
        self.assertEqual(
            nformat(Decimal("1234"), ".", grouping=2, thousand_sep=","), "1234"
        )
        self.assertEqual(
            nformat(
                Decimal("1234"), ".", grouping=2, thousand_sep=",", force_grouping=True
            ),
            "12,34",
        )
        self.assertEqual(nformat(Decimal("-1234.33"), ".", decimal_pos=1), "-1234.3")
        self.assertEqual(
            nformat(Decimal("0.00000001"), ".", decimal_pos=8), "0.00000001"
        )
        self.assertEqual(nformat(Decimal("9e-19"), ".", decimal_pos=2), "0.00")
        self.assertEqual(nformat(Decimal(".00000000000099"), ".", decimal_pos=0), "0")
        self.assertEqual(
            nformat(
                Decimal("1e16"), ".", thousand_sep=",", grouping=3, force_grouping=True
            ),
            "10,000,000,000,000,000",
        )
        self.assertEqual(
            nformat(
                Decimal("1e16"),
                ".",
                decimal_pos=2,
                thousand_sep=",",
                grouping=3,
                force_grouping=True,
            ),
            "10,000,000,000,000,000.00",
        )
        self.assertEqual(nformat(Decimal("3."), "."), "3")
        self.assertEqual(nformat(Decimal("3.0"), "."), "3.0")
        # Very large & small numbers.
        tests = [
            ("9e9999", None, "9e+9999"),
            ("9e9999", 3, "9.000e+9999"),
            ("9e201", None, "9e+201"),
            ("9e200", None, "9e+200"),
            ("1.2345e999", 2, "1.23e+999"),
            ("9e-999", None, "9e-999"),
            ("1e-7", 8, "0.00000010"),
            ("1e-8", 8, "0.00000001"),
            ("1e-9", 8, "0.00000000"),
            ("1e-10", 8, "0.00000000"),
            ("1e-11", 8, "0.00000000"),
            ("1" + ("0" * 300), 3, "1.000e+300"),
            ("0.{}1234".format("0" * 299), 3, "0.000"),
        ]
        for value, decimal_pos, expected_value in tests:
            with self.subTest(value=value):
                self.assertEqual(
                    nformat(Decimal(value), ".", decimal_pos), expected_value
                )

    def test_decimal_subclass(self):
        class EuroDecimal(Decimal):
            """
            Wrapper for Decimal which prefixes each amount with the € symbol.
            """

            def __format__(self, specifier, **kwargs):
                amount = super().__format__(specifier, **kwargs)
                return "€ {}".format(amount)

        price = EuroDecimal("1.23")
        self.assertEqual(nformat(price, ","), "€ 1,23")