Promisable WEB Worker Runner

Run task on web worker and retrieve the result, simply by Promise api.

How to use it

Inside the main script, import and initialize a WorkersManager

// include WorkersManager.js first
var workersManager = new WorkersManager();

Inside the worker executive script, import and initialize a ActualWorker with a work method

There're two ways to initialize a ActualWorker:

1. Directly pass work method to constructor:

javascript // include ActualWorker.js first var worker = new ActualWorker({work: fnDoWork});

2. Extend to a sub class of `ActualWorker` (by es6 js):

```javascript
// include ActualWorker.js first
class RealWorker extends ActualWorker {
    work: fnDoWork
}

var worker = new RealWorker();

Use WorkersManager to run work. E.g.:

workersManager
    .work(inputData)
    .then(function (outputData) {
        ...
    })
    .catch(function (outputError) {
        ...
    });

API

// Create a new worker and let it do the work with specified data
// @returns Promise with work output data if succeeds
WorkersManager.prototype.work(data: *, workerFile: string/*url to a worker script file*/)

// Receive work input and produce direct output or Promise for aync
// @returns * | Promise with work output data if succeeds
ActualWorker.prototype.work(data: *)