Companion server upload events

[mifi]

Expose companion emitter to allow the consumer to subscribe to upload success/failure events

fixes #3435

example code for how to listen to upload events: (can add to companion documentation)

const companionApp = companion.app(options)
const { companionEmitter: emitter } = companionApp

emitter.on('upload-start', ({ token }) => {
  console.log('Upload started', token)

  function onUploadEvent(message) {
    if (message.action === 'success') {
      emitter.off(token, onUploadEvent)
      console.log('Upload finished', token, message.payload.url);
    } else if (message.action === 'error') {
      emitter.off(token, onUploadEvent)
      console.error('Upload failed', message.payload);
    }
  }
  emitter.on(token, onUploadEvent)
})

Other improvements:

• timeout waiting for client connection - fixes memory leak
• fix test

[Murderlon]

Can emitter.off also disable internal events which companion relies on? We have this problem in Uppy

[mifi]

Can emitter.off also disable internal events which companion relies on? We have this problem in Uppy

As far as I know it will only remove the listener function that you specify

From https://nodejs.org/api/events.html#emitterremovelistenereventname-listener :

Removes the specified listener from the listener array for the event named eventName.

[mifi]

While working on this I got hit by a lot of issues related to tests depending on global state, so I created an issue about this: #3545