tuplo/numberfmt

import { getDigitsFormat } from "../helpers/digits-format";
import { getFractionDigits } from "../helpers/fraction-digits";
import {
    rgFractionDigitsAreaOptional,
    rgOptionalDigits,
} from "../helpers/regex";

function handleOptionalDigits(value: number, digits: [number, number]) {
    const [required] = digits;

    return required;
}

export function getMinimumFractionDigits(value: number, format: string) {
    const digitsFormat = getDigitsFormat(format);
    const [required, optional] = getFractionDigits(digitsFormat);

    if (rgFractionDigitsAreaOptional.test(digitsFormat)) {
        const strNumber = value.toString();
        if (rgOptionalDigits.test(digitsFormat)) {
            return handleOptionalDigits(value, [required, optional]);
        }

        return strNumber.indexOf(".") > -1 ? required : 0;
    }

    return rgOptionalDigits.test(digitsFormat) ? required : required + optional;
}