getValue.ts

const numberInput = document.createElement('input');
numberInput.type = 'number';
export function getValidValue(value: string) {
	if (!this.isUserInput) {
		numberInput.value = value;
		return numberInput.value;
	}

	if (value === '' || value === '-' || value === '.') {
		return value;
	}

	const decimalSplit = value.split('.');
	let valueSuffix = '';
	if (decimalSplit.length === 2 && decimalSplit[1] === '') {
		valueSuffix = '.';
		numberInput.value = value.slice(0, -1);
	} else {
		numberInput.value = value;
	}

	if (numberInput.value === '') {
		return this.currentValue;
	}
	return numberInput.value + valueSuffix;
};

old.getValidValue.ts

export function getValidValue(value: string) {
    function isValueInvalidValid(value: string): boolean {
        return decimalSplit.length > 3 || !!value.match(/\.\.+/gm) || isNaN(parseFloat(validValue));
    }

    function removePossibleTrailingExtraDecimal(value: string): string {
        if (decimalSplit.length === 3 && decimalSplit[2] === '') {
            value = decimalSplit[0] + '.' + decimalSplit[1];
        }
        return value;
    }

    function addLeadingOrTrailingDecimal(value: string): string {
        if (decimalSplit.length === 2) {
            if (decimalSplit[1] === '') {
                value += '.';
            } else if (decimalSplit[0] === '') {
                value = '.' + decimalSplit[1];
            }
        }
        return value;
    }

    function setInMinMaxBoundaries(value: string, min: number, max: number) {
        const numericValue: number = parseFloat(parseFloat(value).toPrecision(12));
        const minValue: number = min !== undefined ? min : numericValue;
        const maxValue: number = max !== undefined ? max : numericValue;

        if (numericValue < minValue) {
            value = minValue.toString();
        } else if (numericValue > maxValue) {
            value = maxValue.toString();
        } else {
            value = numericValue.toString();
        }

        return value;
    }

    if (value === '-') {
        return '-';
    }

    const decimalSplit = value.split('.');
    let validValue: string = value;

    if (isValueInvalidValid(validValue)) {
        return '';
    }

    validValue = removePossibleTrailingExtraDecimal(validValue);

    validValue = setInMinMaxBoundaries(validValue, this.min, this.max);

    validValue = addLeadingOrTrailingDecimal(validValue);

    return validValue;
}