Simple in-memory cache implementation for JavaScript

cache.js

/**
 * @typedef CacheOptions
 * @type {object}
 * @property {number | undefined} maxSize
 * @property {number | undefined} maxAge Max Age in Minutes
 * @property {any[] | undefined} entries
 */

class Cache extends Map {

	/**
	 * @param {CacheOptions} options
	 */
	constructor({ maxSize, maxAge, entries }) {
		super(entries);

		this.maxSize = maxSize;
		this.maxAge = maxAge;
	}

	deleteOldestEntry() {
		let keyOfOldestItem, dateOfOldestItem;

		super.forEach(({ date }, key) => {
			if (!dateOfOldestItem || dateOfOldestItem > date) {
				dateOfOldestItem = date;
				keyOfOldestItem = key;
			}
		});

		if (keyOfOldestItem) {
			super.delete(keyOfOldestItem);
		}
	}

	/**
	 * @param key
	 * @param value
	 * @return {Cache}
	 */
	set(key, value) {
		if (!super.has(key) && this.maxSize && super.size >= this.maxSize) {
			this.deleteOldestEntry();
		}

		super.set(key, {
			value,
			date:  new Date(),
		});

		return this;
	}

	/**
	 * @param key
	 * @return {undefined | any}
	 */
	get(key) {
		return this.has(key) ? super.get(key).value : undefined;
	}

	/**
	 * @param key
	 * @return {boolean}
	 */
	has(key) {
		if (super.has(key)) {
			const entry = super.get(key);
			const age = Math.round((new Date() - entry.date) / 60000);

			if (this.maxAge && this.maxAge <= age) {
				super.delete(key);
				return false;
			}

			return true;
		}

		return false;
	}
}