CODEWITHSUNDEEP
javascriptangularjsunit-testingsinon
spinker
spinker

Reputation: 308

how to write unit test to "request" node module with sinon.stub?

I have this function in my code :

let request = require("request");
let getDrillDownData = function (userId, query, callback) {

query.id = userId;
let urlQuery = buildUrlFromQuery(query);

request.get({
    url: urlQuery,
    json: true
}, function (error, response, data) {
    if (!error && response.statusCode === 200) {
        return callback(null, calculateExtraData(data));
    } else if (error) {
        return callback(error, null);
    }
});


};

and I wish to write some unit test which verify that when the function is called with correct parameters, it is running OK, and if there is an error, it did return the error

I wrote this unit test code :

describe.only('Server Service Unit Test', function(){
var sinon = require('sinon'),
    rewire = require('rewire');

var reportService;
var reportData = require('./reportData.json');

beforeEach(function(){
    reportService = rewire('../../services/reports.server.service');
});

describe('report methods', function(){
    var reportData;
    var query = { id: "test"};
    var userId = 'testuser';
    var getDrillDownData;

    var request;

    beforeEach(function(){
        getDrillDownData = reportService.__get__('getDrillDownData');
    });

    it ('should get drill down data by userId and query', function(done){
        var getCallback = sinon.stub();

        request = {
            get: sinon.stub().withArgs({
                url: query,
                json: true
            }, getCallback.withArgs("error", {statusCode: 200}, reportData))
        };

        reportService.__set__('request', request);

        getDrillDownData(userId, query, function(err, returnData){
            (err === null).should.eql(true);
            //(getCallback.withArgs(undefined, {statusCode: 200}, reportData).calledOnce).equal(true);
            done();
        });
});
});

But I keep getting this error:

Error: timeout of 2000ms exceeded. Ensure the done() callback is being called in this test.

Can someone help? Thanks

Upvotes: 2

Views: 2156

Answers (1)

robertklep
robertklep

Reputation: 203534

I would stub request.get() directly:

describe('report methods', function() {

  // Make `request.get()` a Sinon stub.
  beforeEach(function() {
    sinon.stub(request, 'get');
  });

  // Restore the original function.
  afterEach(function() {
    request.get.restore();
  });

  it ('should get drill down data by userId and query', function(done) {
    // See text.
    request.get.yields(null, { statusCode : 200 }, { foo : 'bar' });

    // Call your function.
    getDrillDownData('userId', {}, function(err, data) {
      ...your test cases here...
      done();
    });
  });
});

Using request.get.yields() (which calls the first function argument that Sinon can find in the argument list; in this case, it's the (error, response, data) callback that gets passed to request.get() in your function) you can tell Sinon which arguments to use to call the callback.

That way, you can check if the callback to request.get() handles all arguments properly.

You can use .withArgs() too (request.get.withArgs(...).yields(...)), although you have to be sure that you're using it correctly; otherwise, if the exact arguments don't match, Sinon will call the original request.get() instead of using the stubbed version.

Instead, I prefer using stub.calledWith() to check for the correct arguments after the call has been made. That integrates much better with Mocha as well, as you can use explicit assertions.

Upvotes: 5

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