After/Ready error handling

[delvedor]

Implementation of the discussion done in fastify/fastify#59.

[mcollina]

I do not think after()  should be called with an error at all. We should bail off the plugin loading.

[delvedor]

Why not, in this way the user can handle the error inside the after.
Example:
If plugin 1 fails => load plugin 2.

[mcollina]

that should be in the register callback, not in after IMHO.

[delvedor]

Agree, but at the moment this is the behaviour:

test('error', (t) => {
  t.plan(2)

  const server = { my: 'server' }
  const app = boot(server)

  app.use(function (s, opts, done) {
    done(new Error('err'))
  }, err => {
    t.ok(err)
    app.use(function (s, opts, done) {
      done()
    })
  })

  app.ready(function (err) {
    t.ok(err)
  })
})

As you can see, we have not that capability, because the error will arrive to the ready callback in every case.
With after I can "block" that error ina specific point, as you can see here:

test('error', (t) => {
  t.plan(3)

  const server = { my: 'server' }
  const app = boot(server)

  app.use(function (s, opts, done) {
    done(new Error('err'))
  }, err => {
    t.ok(err)
  })

  app.after(function (err) {
    t.ok(err)
    app.use(function (s, opts, done) {
      done()
    })
  })

  app.ready(function (err) {
    t.error(err)
  })
})

This is why yesterday I was saying that we should raise the error in the ready callback only if the error is not handled in the use callback.

[mcollina]

OK for this behavior you are describing right know.

[delvedor]

Sorry, I didn't understand, do you want me to implement this behaviour?

This is why yesterday I was saying that we should raise the error in the ready callback only if the error is not handled in the use callback.

[mcollina]

This is why yesterday I was saying that we should raise the error in the ready callback only if the error is not handled in the use callback.

yes.

[mcollina]

LGTM