Convert a step value to a corresponding T-shirt size

convertToTShirtSize.js

/**
 * Converts a step value to a corresponding T-shirt size.
 * The default value '0' is equal to 'm'.
 * @param {number} step - The step value to convert into a T-shirt size.
 * @returns {string} The T-shirt size corresponding to the given step value.
 */
const convertToTShirtSize = (step = 0) => {
	const times = Math.max(0, Math.abs(step) - 1);
	const index = Math.sign(step) + 1;
	return 'x'.repeat(times) + ['s','m','l'][index];
}