happy-dom/src/nodes/html-input-element/HTMLInputElementValueStepping.ts

Happy DOM is a JavaScript implementation of a web browser without its graphical user interface. It includes many web standards from WHATWG DOM and HTML.

import DOMException from '../../exception/DOMException.js';

/**
 * HTML input element value stepping.
 */
export default class HTMLInputElementValueStepping {
	/**
	 * Steps up or down.
	 *
	 * @param type Type.
	 * @param value Value.
	 * @param direction Direction.
	 * @param [increment] Increment.
	 * @returns New value.
	 */
	public static step(type: string, value: string, direction: -1 | 1, increment?: number): string {
		switch (type) {
			case 'number':
				return String(
					Number(value) + (increment !== undefined ? increment * direction : direction)
				);
			case 'date':
			case 'month':
			case 'week':
			case 'time':
			case 'datetime-local':
			case 'range':
				// TODO: Implement support for additional types
				return null;
			default:
				throw new DOMException('This form element is not steppable.');
		}
	}
}