Promise-based wrapper for space-constrained Node.js applications (aws lambda, gc functions, etc)

request.js

/**
 * A Promise-based wrapper for the http/https.request function
 * @param {string|URL} url - Strings are parsed as URL objects
 * @param {Object} opts - A set of options for http.request - includes `body`
 * @example let response = await request('http://jsonplaceholder.typicode.com/posts/1')
 */
function request(url, opts) {
    return new Promise((resolve, reject) => {

        if (!(url instanceof URL)) {
            url = new URL(url);
        }

        const lib = url.protocol == 'https:' ? require('https') : require('http');

        const req = lib.request(url, { ...opts }, res => {
            res.setEncoding('utf8');

            const isSuccess = String(res.statusCode).startsWith('2');
            const isRedirect = String(res.statusCode).startsWith('3');
            
            const callback = data => {
                if (isRedirect && res.headers.location) {
                    request(res.headers.location, opts).then(resolve);
                } else if (isSuccess) {
                    resolve(data);
                } else {
                    reject(data);
                }
            }
            
            let buffer = '';

            res.on('data', data => buffer += data);
            res.on('end', _ => callback(buffer));
            res.on('error', error => reject(error));
        });

        req.on('timeout', _ => req.destroy());
        req.on('error', error => reject(error));

        if (opts && opts.body) {
            req.write(opts.body);
        }

        req.end();
    });
}