zurvan/tests/ComplexScenarioTests.js

A library for simulating time in Node.js

'use strict';
var assert = require('assert');
var zurvan = require('../zurvan');
var bluebird = require('bluebird');

var NodeVersion = require('../detail/utils/NodeVersion');

describe('zurvan', function() {
  var expectedOrder = NodeVersion.features.hasMicroqueuedNextTick
    ? [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]
    : [1, 3, 5, 2, 4, 6, 7, 11, 8, 9, 12, 13, 14, 10, 15, 18, 16, 17];

  complexTestSuite('bluebird', bluebird, expectedOrder);

  if (NodeVersion.features.hasPromise) {
    complexTestSuite('native', global.Promise, expectedOrder);
  }

  function complexTestSuite(name, scheduler, expectedCallOrder) {
    describe(
      'after intercepting timers with ' + name + ' scheduler',
      function() {
        beforeEach(function() {
          return zurvan.interceptTimers({
            promiseScheduler: scheduler,
            bluebird: bluebird
          });
        });

        afterEach(function() {
          return zurvan.releaseTimers();
        });

        it('can handle complex scenarios on the queue in a single moment', function(done) {
          var calls = [];
          setImmediate(function() {
            calls.push(1);
            process.nextTick(function() {
              calls.push(3);
              process.nextTick(function() {
                calls.push(5);
                setImmediate(function() {
                  calls.push(7);
                  process.nextTick(function() {
                    calls.push(11);
                  });
                });
                setImmediate(function() {
                  calls.push(8);
                  setImmediate(function() {
                    calls.push(15);
                    process.nextTick(function() {
                      calls.push(18);
                    });
                  });
                });
                setImmediate(function() {
                  calls.push(9);
                  process.nextTick(function() {
                    calls.push(12);
                    process.nextTick(function() {
                      calls.push(13);
                      process.nextTick(function() {
                        calls.push(14);
                        setImmediate(function() {
                          calls.push(17);
                        });
                      });
                      setImmediate(function() {
                        calls.push(16);
                      });
                    });
                  });
                });
              });
            });
          });

          zurvan
            .waitForEmptyQueue()
            .then(function() {
              assert.deepEqual(calls, expectedCallOrder);
              assert.equal(process.uptime(), 0);
            })
            .then(done, done);

          setImmediate(function() {
            calls.push(2);
            process.nextTick(function() {
              calls.push(4);
              process.nextTick(function() {
                calls.push(6);
                setImmediate(function() {
                  calls.push(10);
                });
              });
            });
          });
        });
      }
    );
  }
});