beelzebub/examples/api/async.js

One Hell of a Task Master!

'use strict';
// !-- FOR TESTS
let wrapper = function (options) {
// --!

// =====================================================
// <EXAMPLE>
  let Beelzebub = require('../../');
  let bz = Beelzebub(options || { verbose: true });

  class MyTasks extends Beelzebub.Tasks {
    constructor (config) {
      super(config);
      this.$setName('MyTasks');

      this._delayTime = 500;
    }

    _delay (message, delay) {
      return new Promise((resolve, reject) => {
        setTimeout(() => {
          this.logger.log(message);
          resolve();
        }, delay);
      });
    }

    /**
     * Promise based task
     */
    task1 () {
      this.logger.log('MyTasks task1: before');
      return this._delay('MyTasks task1: promise delay ' + this._delayTime, this._delayTime)
        .then(() => {
          this.logger.log('MyTasks task1: after');
        });
    }

    /**
     * generator based tasks
     */
    * task2 () {
      let delay = this._delayTime + 200;
      this.logger.log('MyTasks task2: before');
      yield this._delay('MyTasks task2: yield delay ' + delay, delay);
      this.logger.log('MyTasks task2: after');
    }

    /**
     * async/await based task
     */
    // async task3() {
    //    this.logger.log('MyTasks task3: before');
    //    await this._delay('MyTasks task3: await delay'+this._delayTime);
    //    this.logger.log('MyTasks task3: after');
    // }
}
  bz.add(MyTasks);

  let p = bz.run( // all args run in sequence
    'MyTasks.task1',
    'MyTasks.task2',
    // 'MyTasks.task3',
    [ // arrays run in parallel
      'MyTasks.task1',
      'MyTasks.task2'
        //, 'MyTasks.task3'
    ]
  );
/* Output:
MyTasks task1: before
MyTasks task1: promise delay 500
MyTasks task1: after
MyTasks task2: before
MyTasks task2: yield delay 700
MyTasks task2: after
MyTasks task1: before
MyTasks task2: before
MyTasks task1: promise delay 500
MyTasks task1: after
MyTasks task2: yield delay 700
MyTasks task2: after
*/
// </EXAMPLE>
// =====================================================

// !-- FOR TESTS
  return p.then(() => { return bz; });
};
module.exports = wrapper;
// if not running in test, then run wrapper
if (typeof global.it !== 'function') wrapper();
// --!