Tasks that return a Promise of a stream

[ineentho]

Is there any particular reason why promises that resolve to a stream aren't supported? For example:

gulp.task('task', () => {
  return Promise.resolve().then(() => {
    return gulp.src(...).pipe(gulp.dest(...))
  })
})

Intuitively, I thought this would be supported, the same way that a Promise that resolves to a Promise waits for both.

Now that async/wait is supported in node, I'd say the case for supporting this is even stronger, take for example (very abstract, I know, but I'm sure you too can see a real world use case for this):

gulp.task('task', async () => {
  const config = await getConfigFromFile()
  return gulp.src(...)
    .pipe(doSomething(config))
    .pipe(gulp.dest(...))
})

Currently I'm using node-promisepipe to work around this, but I think this could be supported natively. Thoughts?

[robrich]

At the surface, I'd expect this to work too. Want to add a pull request with a failing test for this case?

[ineentho]

Sure, done. While I was at it, I noticed that because of the promise, all errors in the start callback were swallowed by the promise. Would it be desirable to run process.nextTick around the done.call in runTask to avoid that?