prev.params should always exist

[timwis]

The code I suggested in #166 (comment) requires you check if prev.params exists before checking one of its properties, otherwise you'll throw a runtime error on the first load.

const view = (state, prev, send) => {
  if (!prev.params || !prev.params.user || prev.params.user !== state.params.user) {
    send('fetch', state.params.user)
  }
  return html`<div>...</div>`
}

This pull request lets you always check properties of prev.params:

const view = (state, prev, send) => {
  if (!prev.params.user || prev.params.user !== state.params.user) {
    send('fetch', state.params.user)
  }
  return html`<div>...</div>`
}

[yoshuawuyts]

💯 yeah nice one - patch version I reckon?

[yoshuawuyts]

Wooh!