Testing Node.js application that uses Kue

Question

I would like to test an application that uses Kue so that job queue is empty before each test and cleared after each test. Queue should be fully functional and I need to be able to check status of jobs that are already in the queue.

I tried mock-kue and it worked well until I had to get jobs from the queue and analyze them. I couldn't get it to return jobs by job ID.

Situations that I need to be able to test:

1. Something happens and there should be a job of a given type in the queue,
2. Something happens and produces a job. Something else happens and that job gets removed and replaced with another job (rescheduling or existing job).

Seams straightforward, but I have hard time wrapping my head around the problem. All pointers are welcome.

Answer 1

In my experience it's more straightforward to simply have redis running on localhost wherever you want to run your tests rather than dealing with a mocked version of kue.

First, to make sure kue is empty before each test it could be as simple as flushing redis, eg:

var kue = require('kue');
var queue = kue.createQueue();

queue.client.flushdb(function(err) {});

For #1, kue has a rangeByType() method that should solve your problem:

var getJobs = function(type, state, cb) {
   kue.Job.rangeByType(type, state, 0, -1, 'asc', cb);    
}
// After something happens
getJobs('myJobType', 'active', function(err, jobs) {});

For #2, you can use the same method and simply keep track of the job id to know that it has been replaced:

var jobId;
getJobs('myJobType', 'active', function(err, jobs) {
    assert.lengthOf(jobs, 1);
    jobId = jobs[0].id;
});

// After the thing happens
getJobs('myJobType', 'active' function(err, jobs) {
    assert.lengthOf(jobs, 1);
    assert.notEqual(jobId, jobs[0].id);
});

And if you ever need to query a job by ID you can do it like so:

kue.Job.get(jobId, function(err, job) {});