documentation request: working example for custom authorizer

Do you want to request a feature or report a bug?

Feature

What is the current behavior?

The README mentions an authorizer but does not provide much detail about options or the expected function signature of callback. Even if these had types, developers without TypeScript would still be left wondering.

What is the expected behavior?

Some description of what to do with options and why the callback receives false (when would it be true?) would be nice. Maybe a short example that uses fetch would be illustrative?

[cainlevy]

@skellock That matches where I ended up as well. Here’s another version:

new Pusher(PUSHER_KEY, {
    cluster: PUSHER_CLUSTER,
    authorizer: (channel, _options) => ({
    authorize: async (socketID, callback) => {
        try {
            const authData = await getPusherAuth(name, socketID);

            callback(false, authData);
        } catch (e) {
            callback(true);
        }
    }
})

This is my best understanding of the authorizer API expressed as a TypeScript interface:

https://github.com/DefinitelyTyped/DefinitelyTyped/blob/9f4c75126167d0d8af759f58405d53d983e94ad0/types/pusher-js/index.d.ts#L126-L128

[skellock]

Apologies in advance for being +1 guy, but this really needs some love.

For future travelers of the internet, here’s what I ended up doing that worked for me.

const PUSHER_KEY = 'abcdef0123abcdef0123' // your 20 hex digits api key
const PUSHER_CLUSTER = '' // e.g. 'mt1'

new Pusher(PUSHER_KEY, {
  cluster: PUSHER_CLUSTER,
  encrypted: true,
  authorizer: ({ name }) => ({
    authorize: async (socketId, callback) => {
      // acquire the token somehow (fetch, or whatever)
      // let pretend this returns a string or null
      // a channel token looks like this:  '<20 hex digits>:<64 hex digits>'
      const channelToken = await loadPusherToken(name)

      if (channelToken) {
        // tell pusher about the token with this format:
        callback(false, { auth: channelToken })
      } else {
        // tell pusher we fail... null is probably not required, i just need symmetry.  :|
        callback(true, null)
      }
    },
  }),
})

FWIW, this was using pusher-js@4.2.2 and react-native@0.53.0.

Docs matter. And given my track record writing 'em, I’m probably the worst person to be dishing up that advice.