Safe lookup

[delvedor]

In the case there are two nodes and one of them is a client node, if the not-client node goes down, the client node will throw an exception here:

swim-hashring/hashring.js

Line 213 in 6d0a92d

return this._entries[index].peer

Because it's searching the key peer on and undefined object.
I'm having some trouble to test this, any suggestion?

Do we agree on the fix?

[mcollina]

Can you add a unit test?

[mcollina]

In which case index >= this._entries.length? I think it might happen, but a comment would be good.

[delvedor]

@mcollina I would like to do it, but I'm having some issue to reproduce the error outside of a project which I'm working on.
This is what I've done so far, but is not working (the close callback is never called):

test('gracefully shutdown a client if there are no more node in the ring', t => {
  t.plan(1)

  const peer = hashring({
    joinTimeout: 1000
  })

  peer.on('up', () => {
    console.log('peer up')
    const client = hashring({
      joinTimeout: 1000,
      client: true,
      base: [peer.whoami()]
    })

    client.on('up', () => {
      console.log('client up')
      peer.close(() => {
        console.log('peer closed')
      })
    })
  })
})