[node. js] Testing ES6 Promises in node. js using Mocha and Chai

Writing great ES6 style Promises for node. JS is only half the battle. Your great modules must include tests as well to ensure the future iterations don ' t break them. In this lesson, I show you a simple ES6 Promise in node. js, then walk to through creating tests in Mocha using Chai and C hai-as-promised to test both resolve and reject methods.

Install:

NPM i-D Chai chai-as-promised

Index.js

Exports.foo = (opts) = = {    return NewPromise (Resolve, Reject)= {            if(opts = = =1) {Reject ('Found An error'); } Else{setTimeout ()={Console.log (opts);                Resolve (opts); },  -); }        }    );}; Exports.foo (2).Catch(Err ={console.log (err);});

Test/index.js:

ConstChai = require ('Chai');ConstExpect =Chai.expect;Constchaiaspromised = require ('chai-as-promised');Constindex = require ('.. /index.js'); Chai.use (chaiaspromised);d Escribe ('Function Foo', () ={It ('should accpet anything but one', () = {        ConstPromise = Index.foo (0); returnExpect (promise). To.eventually.equal (0);    }); It ('should throw error is apply one', () = {        ConstPromise = Index.foo (1); //return expect (promise). to.be.rejected;        returnExpect (promise). To.be.rejectedWith ('Found An error'); })});

[node. js] Testing ES6 Promises in node. js using Mocha and Chai