Compiler: something up with promise catch

[josephjclark]

I confused myself over this today and it became a problem

I want to do this:

each($.data, get()
  .then(...)
  .catch(...)
)

Ie for each item, I call get(), and I do one thing if the request succeeds, and another thing if it fails.

But I think there's a problem on the catch, because it doesn't receive a state object. Or maybe it receives a wierd one? Or wait I think I'm catching an error on the .then() handler, not the get itself?

This also doesn't work:

each($.data, get()
  .catch(...)
  .then(...)
)

Because it'll catch the error and THEN trigger the .then(), which isn't what we want.

Something is up here, and the docs don't show an example of a .then() AND a .catch() on the same operation. Need to investigate, fix and clarify.

Also, while I'm here, need to ensure that catch receives the last-good-state (the state before the throw), and that whatever the catch returns is the next state going forward.

[josephjclark]

This code behaves as I expect:

fn(s => {
  throw {}
})
  .catch((s) => Object.assign(s, { catch: true }))
  .then((s) => Object.assign(s, { then: true }))

fn(s => {
  console.log(s)
  return s
})

Which is to say:

• fn throws
• it is caught by catch()
• then() does not get called

It compiles like this:

export default [
	_defer(
		fn(s => {
		  throw {}
		}),
		p => p.then((s) => Object.assign(s, { then: true })),
		(s) => Object.assign(s, { catch: true })
	),
	fn(s => {
  console.log(s)
  return s
})];

Which is hard to read, but it's basically doing this:

export default [
	_defer(fn, then, catch),
	fn(),
];

Which is what I expect

[josephjclark]

This also behaves correctly - and this is basically just stripped down customer code:

fn((s) => {
	s.data=[1,2,3]
	return s;
})

each(
  $.data,
  fn((state) => {
  	if(state.data === 2 )  {
	  	throw new Error(state,data)
	  }
	  return state
  })
    .catch((error, state) => {
      console.log('CATCH',state.data)
      return state;
    })
    .then((state) => {
      console.log('THEN', state.data)
      return state;
    })
);