Dangerous Behavior

[tech-a-go-go]

Hi there,

Please take a look at this simple code.

const Promise = require('bluebird');
const StateMachine = require('fsm-as-promised');
StateMachine.Promise = Promise;

var fsm = StateMachine({
    initial: 'here',
    events: [
      { name: 'jump', from: 'here', to: 'sky' },
      { name: 'run',  from: 'here', to: 'office' },
    ],
    callbacks: {
      onjump: function (options) {
        return new Promise(function (resolve, reject) {
          resolve(options);
        });
      }
    }
  });

fsm.jump().then((a) => {
  console.log('jump', fsm.current, a);
}).catch((err) => {
  console.log('err jump', err);
});

fsm.run().then((a) => {
  console.log('run', fsm.current, a);
}).catch((err) => {
  console.log('err run', err);
});

I thought fsm.jump() will succeed and fsm's state will be sky and fsm.run() will fail because fsm's state has already been changed to sky.

But the result is as follows.

jump office { name: 'jump', from: 'here', to: 'sky', args: [] }
run office { name: 'run', from: 'here', to: 'office', args: [] }

jump office !?

jump can only go to the sky...

I know jump() and run() are not connected with a promise chain so while jump() was being processed, run() was executed and run()'s result was taken effect at last.
I believe run() should throw an error or return a promise reject when it's called while other events are being processed..

I think this is very dangerous.

Cheers

[vstirbu]

@tech-a-go-go thanks for spotting this behaviour! it was not just dangerous, it was plain faulty...