index.js

/** @typedef {import('./index').HTTPMethods} HTTPMethods */

if (!globalThis.fetch || typeof globalThis.fetch !== 'function') {
	throw new Error("Couldn't find fetch!");
}

/**
 * Validate URL function.
 * @param {string} url URL want to validate.
 * @return {boolean}
 */
function validateUrl(url) {
	try {
		return !!new URL(url);
	} catch {
		return false;
	}
}

/**
 * Resolve URL w/ (baseURL)
 * @param {string | URL} url Children url
 * @param {string | URL} baseUrl Parent url
 * @param {boolean} forceHost Force change the baseUrl
 * @return {URL}
 */
function resolveUrl(url, baseUrl, forceHost) {
	if (url instanceof URL) {
		if (
			baseUrl instanceof URL &&
			url.hostname !== baseUrl.hostname &&
			forceHost
		) {
			return new URL(url.pathname, baseUrl);
		}
	}
	if (
		baseUrl &&
		((typeof baseUrl === 'string' && baseUrl.length) ||
			baseUrl instanceof URL) &&
		validateUrl(baseUrl)
	) {
		baseUrl = new URL(baseUrl);
		if (baseUrl.hostname === 'localhost') baseUrl.hostname = '127.0.0.1';
		return new URL(url, baseUrl.href);
	} else {
		if (!validateUrl(url)) throw new TypeError('Invalid URL');
		else return new URL(url);
	}
}

/**
 * @class FetchPrefixUrl
 */
class FetchPrefixUrl {
	/**
	 * @param {string} baseUrl Request Base URL.
	 */
	constructor(baseUrl) {
		/** @private */
		this.baseUrl = resolveUrl(baseUrl);
	}

	/**
	 * Request
	 * @param {string | URL} url Children URL.
	 * @param {HTTPMethods} method HTTP Request Methods.
	 * @param {RequestInit} input Request input data.
	 * @return {Promise<Response>}
	 */
	async request(url, method = 'GET', input) {
		if (!/^(get|p(os|u)t|delete|options|head)$/gi.test(method))
			throw new TypeError('Invalid HTTP Method');
		method = method.toUpperCase();
		input = input || {};
		input.headers = {
			'User-Agent': 'FetchPrefixUrl/1.0',
			...input.headers,
			'Access-Control-Allow-Origin': '*',
		};
		try {
			return await fetch(resolveUrl(url, this.baseUrl, false).href, {
				method,
				...input,
			});
		} catch (err) {
			return { error: err.message };
		}
	}

	/**
	 * Do GET Request
	 * @param {string | URL} url Requested URL.
	 * @param {RequestInit} options Request options.
	 * @return {Promise<Response>}
	 */
	get(url, options) {
		return this.request(url, 'GET', options);
	}

	/**
	 * Do HEAD Request
	 * @param {string | URL} url Requested URL.
	 * @param {RequestInit} options Request options.
	 * @return {Promise<Response>}
	 */
	head(url, options) {
		return this.get(url, {
			...options,
			method: 'HEAD',
		});
	}

	/**
	 * Do POST Request
	 * @param {string | URL} url Requested URL.
	 * @param {string | Object | Array} body Requested body.
	 * @param {RequestInit} options Request options.
	 * @return {Promise<Response>}
	 */
	post(url, body, options) {
		if (Array.isArray(body) || typeof body === 'object')
			body = JSON.stringify(body);
		else if (body instanceof URLSearchParams) body = body.toString();
		return this.request(url, 'POST', {
			...options,
			body,
		});
	}

	/**
	 * Do DELETE Request
	 * @param {string | URL} url Requested URL.
	 * @param {RequestInit} options Request options.
	 * @return {Promise<Response>}
	 */
	delete(url, options) {
		return this.get(url, {
			...options,
			method: 'DELETE',
		});
	}

	/**
	 * Do OPTIONS Request
	 * @param {string | URL} url Requested URL.
	 * @param {RequestInit} options Request options.
	 * @return {Promise<Response>}
	 */
	option(url, options) {
		return this.request(url, 'OPTIONS', {
			...options,
			body,
		});
	}

	/**
	 * Set current base url.
	 * @param {string} url Set the base URL.
	 * @return {void}
	 */
	setBase(url) {
		this.baseUrl = resolveUrl(url);
	}
}

export { FetchPrefixUrl, resolveUrl, validateUrl };