René's URL Explorer Experiment

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Promisify server.listen","articleBody":"### Problem:\r\n```js\r\nconst server = app.listen();\r\nconsole.log(`Server listening on: ${server.address().port}`)\r\n```\r\ncan fail, as the server is created asynchronously and using the callback is not always practical/flexible\r\n\r\n### Proposal\r\neither `server.listenPromise(port)`, or even better, have `server.listen(port)` return a Promise if no callback is provided\r\n\r\n### Example\r\n```js\r\n\r\n// .... \r\n\r\nconst start = async () => {\r\n    await config.load();\r\n    await DB.connect(dbOptions);\r\n    router(app);\r\n    app.use((err, req, res, next) => { // error handler\r\n        // ...\r\n    });\r\n\r\n    const server = http.createServer(app);\r\n    // proposal:\r\n    return server.listen(process.env.PORT || 3000); // if .listen would be a promise resolving to server\r\n    // or await server.listen(...); return server; else\r\n\r\n    // currently I have to do:\r\n    // return new Promise((res, rej) => server.listen(process.env.PORT || 3000, err => err ? rej(err) : res()));\r\n\r\n    // or using express's app.listen, which wraps createServer and listen:\r\n    // return new Promise((res, rej) => app.listen(process.env.PORT || 3000, function (err) {\r\n    //      if (err) return rej(err);\r\n    //      res(this) // this is node's http Server\r\n    // }));\r\n\r\n    // using util.promisify doesn't look much better:\r\n    // return promisify(server.listen).bind(server)(process.env.PORT || 3000);\r\n    // or\r\n    // return promisify(cb => server.listen(process.env.PORT || 3000, cb))();\r\n};\r\n```\r\n\r\nthen using it somewhere else:\r\n```js\r\nstart()\r\n        .then(server => console.log(`Server listening on: ${server.address().port}`))\r\n        .catch(err => {\r\n           // ...\r\n        });\r\n```\r\n\r\nEdit: I'll try to submit this request to express, and have a similar promise method near https://github.com/expressjs/express/blob/master/lib/application.js#L616-L619\r\n\r\nEdit2: the discussion in expressjs/express#3675 has interesting details","author":{"url":"https://github.com/caub","@type":"Person","name":"caub"},"datePublished":"2018-06-23T07:11:43Z","url":"https://github.com/nodejs/node/issues/21482"}