test.js

// Run with mocha: http://visionmedia.github.com/mocha/
var assert = require('assert');
var SyncQueue = require('./SyncQueue');
var sq = null;

describe('SyncQueue.js tests', function () {
  before(function () {
    sq = new SyncQueue();
  });
  it('should execute asynchronous jobs in FIFO order and maintain proper state', function (done) {
    // Track current runs and total planned runs
    var runs = 0;
    var total = 10;
    // Generate total # jobs to execute
    for (var i = 0; i < total; i++) {
      (function (j) {
        sq.push(function (next) {
          setTimeout(function () {
            // Check job number against current run number
            assert.equal(j, runs++);
            // Execute next job
            next();
          }, 100 - (j * 10)); // Each job runs faster than the last
        });
      })(i);
    }
    // Push one final job to be executed at the very end
    sq.push(function (next) {
      // Check queue state to be running and have run the proper number of jobs
      assert.equal(true, sq._running);
      assert.equal(total, runs);
      // There is no next job, so this will shut down the queue until there is a next job
      next();
      // Check queue state to be not running and have zero jobs in queue
      assert.equal(false, sq._running);
      assert.equal(0, sq._queue);
      // Now that queue has been verified to be shut down, push one more job to make sure it can start back up
      sq.push(function (next) {
        // This last job finishes the test
        done();
      });
    });
  });
});