How to test an API that calls another external API in node

Question

I'm using mocha, chai, and chai-http to test my simple API that routes calls from Slack to Habitica, integrating these two services.

I'm trying to start by creating tests, but I'm facing this issue: when I call my API, the code returns before the external API call. This is the code of the test:

var chai = require("chai");
var chaiHttp = require("chai-http");
var server = require("../src/app/index");
var should = chai.should();

chai.use(chaiHttp);

describe("/GET list", () => {
    it("it should return a list of user\'s tasks", (done) => {
        chai.request(server)
        .post("/habitica")
        .type("urlencoded")
        .send({text: "list"})
        .end((err, res) => {
            res.should.have.status(200);
            res.body.should.be.a("object");
            res.body.should.have.property("success").eql("true");
            done();
        });
    });
});

This is the code that is been called by the test:

app.post("/habitica", server.urlencodedParser, function(req, res) {
    if (typeof req.body !== "undefined" && req.body) {
        switch(req.body.text) {
            case "list":
                request({
                    url: GET_TASKS,
                    headers: { "x-api-user": process.env.HABITICA_USERID, "x-api-key": process.env.HABITICA_APITOKEN }
                }, function (apiError, apiResponse, apiBody) {
                    if (apiError) {
                        res.send(apiError);
                    } else {
                        res.send(apiBody);
                    }
                });
                break; 
            default: 
                res.send({
            "success": "false",
            "message": "Still working on tasks creation"
        });
        }
    }
});

This code returns before the call to Habitica return any value. This is the result of "npm test":

  /GET list
    1) it should return a list of user's tasks


  0 passing (2s)
  1 failing

  1) /GET list
       it should return a list of user's tasks:
     Uncaught AssertionError: expected {} to have property 'success'
      at chai.request.post.type.send.end (test/app.js:17:34)
      at Test.Request.callback (node_modules/superagent/lib/node/index.js:706:12)
      at IncomingMessage.parser (node_modules/superagent/lib/node/index.js:906:18)
      at endReadableNT (_stream_readable.js:974:12)
      at _combinedTickCallback (internal/process/next_tick.js:80:11)
      at process._tickCallback (internal/process/next_tick.js:104:9)

I've already searched in a lot of forums and sites:

Some people say that I shouldn't test code I don't own: this makes a lot of sense, but what should I've been testing since it is just a simple integration service?
Some people say that I should mock the external api result: but I won't been testing anything since, again, it is just an integration.

How can I solve this?

Thanks in advance.

So you have an endpoint /habitica in your application right? or it's third party service? — mandar.gokhale, May 10 '18 at 16:08
Yes, I have this endpoint in my application. This endpoint calls the [habitica API](https://habitica.com/apidoc/) which is the third party service. — André Maldonado, May 10 '18 at 17:19
@AndréMaldonado do you solve your problem? if yes, how can you solve it? — Slim, May 20 '19 at 12:01

score 1 · Answer 1 · answered May 10 '18 at 18:02

You should mock the calls to external API & test how your app should behave in case of failure or success after calling the external API. You can test different scenarios as follows

describe("/GET list", () => {
  // pass req.body.text = 'list'
  describe("when task list is requested", () => {
     describe("when task list fetched successfully", () => {
        // in beforeEach mock call to external API and return task list
        it('returns tasks list in response', () => {
        })
     }),
     describe("when error occurs while fetching task list", () => {
       // in beforeEach mock call to external API and return error
       it('returns error in response', () => {
       })
     })
  }),
  // when req.body.text != 'list'
  describe("when task list is not requested", () => {
     it('returns error in response', () => {
     })
  })
})

How to test an API that calls another external API in node

1 Answers1