Test Promise without trying expect() inside then() callback.

[AlirezaEthDev]

As I read Chai Http, Whenever we need to test a promise by Chai Http, we should try expect() in a then() callback function, like this:

chai.request(app)
  .put('/user/me')
  .send({ password: '123', confirmPassword: '123' })
  .then(function (res) {
     expect(res).to.have.status(200);
  })

My questiona are:

1. Is it possible to try expect() for a promise in out of then(), For example in another js file that requires this file?
2. How can I do that?

[keithamus]

Hey @AlirezaEthDev thanks for the issue.

The best way to do this is with async/await:

test('the thing', async () => {
  expect(
    await chai.request(app)
//  ^ note the "await"
      .send({ password: '123', confirmPassword: '123' })
  ).to.have.status(200)
})

If you can't use async await you could try chai-as-promised:

chai.use(require('chai-as-promised'))
test('the thing', () => {
  return expect(
    chai.request(app)
    .send({ password: '123', confirmPassword: '123' })
  ).to.eventually.have.status(200)
  //   ^ note the "eventually" from chai-as-promised
})

[keithamus]

Without knowing what reqTo.postReq() does I can't give you an answer I'm afraid. I can provide some basic guidelines:

• reqTo.postReq() should return a Promise of the result.
• have.status(200) will test that the result is a Chai Request Test Result (the thing that chai.request(app) creates). If it isn't, the test will fail. So reqTo.postReq() will need to call chai.request(app) internally.

[AlirezaEthDev]

Thanks again.
reqTo is:

const axios=require("axios");
const myReq={
    username:<username>,
     password: <password>
}

exports.postReq=function(){
    axios.post("http://127.0.0.1:8000/auth/",myReq).then(function(res){
       return res;
    });
}

As you see, I'm using Axios for requesting in my main code. According to your reply, I should send requests by chai.request(app)... instead axios.post(...)... in my main code, are I right?

[keithamus]

If you want to use chai-http you'll need to use chai.request(app), yes. If you want to continue to use axios, you can do so without chai-http, but you'll use regular assertions instead of the chai-http ones. If you do an internet search for "chai axios" you will come across a variety of articles about how to write tests in chai using axios.

[AlirezaEthDev]

Ok, I search and feedback to you. Yes, I want to continue to use axios.

[AlirezaEthDev]

@keithamus Hi again!
Finally, After some research I could solve the issue by JavaScript Promise object. I don't claim this is the best solution but it works.

Solution:

1. I modified reqTo.js:

const axios=require("axios");
const myReq={
    username:<username>,
     password: <password>
  }

exports.postReq=async function(){
    return await axios.post("http://127.0.0.1:8000/auth/",myReq);
}

As you can see, I just changed postReq() to an async function and removed .then() after axios.post().

2. I used this code in the test file that applies JavaScript Promise object:

const reqTo=require(".../app/reqTo.js");
const chai=require("chai");
const { describe } = require("mocha");
const expect=chai.expect;

    describe("Test Promise",function(){
        it("Test by new Promise",function(){
                    const promise=new Promise(async function(myResolve,myReject){
                        const result=await reqTo.postReq();
                              if(result.status==200){
                                myResolve(200);
                              }else{
                                myReject("Error: Expected "+result.status+" to be equal to 200");
                              }
                });
               promise.then(
                   function(value){expect(value).to.equal(200);
                       console.log("Resolved: "+value);
                }
               ).catch(function(err){
                   console.log(err);
               });
        })
    });

And I it works.

Thanks for your helps and guides!