Re-render markup when components prop changes

[d3x7r0]

Fix for issue #25: change the shouldComponentUpdate function to allow re-rendering when the components prop changes.

[developit]

I know I'd suggested this implementation previously, but I think we might be able to swap it and save a few bytes+ticks. Also Object.keys(undefined) throws, which seems like it would make the component error out if components={} weren't passed.

if (components) {
  // we have a list of components, but there wasn't one before:
  if (!p.components) return true;
  for (let i in components) {
    // one of the components changed:
    if (p.components[i]!==components[i]) return true;
  }
  for (let i in p.components) {
    // one of the components was removed:
    if (!(i in components)) return true;
  }
}
else if (p.components) {
  // we used to have a list of components, but don't anymore:
  return true;
}

[d3x7r0]

Good catch. Sorry it took me so long to reply but I've done the change now.

[d3x7r0]

I see that the lib got bumped to preact X (👍) but now my new tests don't run (☹️). Any idea how I can test the updates without preact-render-spy?

[developit]

Should work with two render() calls - the tests run in a browser environment, so rendering is okay:

const XFoo = () => (<div class="x-foo">hello foo</div>);
const XBar = () => (<div class="x-bar">hello bar</div>);

render(
	<Markup type="html" markup='<x-component />' components={{ XComponent: XFoo }} />,
	scratch
);

expect(scratch.textContent).to.equal('hello foo');

render(
	<Markup type="html" markup='<x-component />' components={{ XComponent: XBar }} />,
	scratch
);

expect(scratch.textContent).to.equal('hello bar');

[developit]

(admittedly, this is less nice than the preact-render-spy version. I really want to make things work together here)

[d3x7r0]

Sorry, real life happened and I had completely forgotten about this until now. I've updated the test with your suggestion. Thanks for the help 👍

[developit]

heh I'm with you there, thanks for jumping back in though!

[developit]

It's weird that Github isn't showing the easy "update" button - I fixed the test runner issue on master.

[d3x7r0]

I rebased with master anyway, that should get Travis running

[d3x7r0]

Hey, can we get this merged? It would really help in my current project.

[danielweck]

This PR looks like it could / should be merged? :)

I would just change this comment:

// one of the components changed:

...with:

// one of the components changed, or a new one was added:

(to more accurately describe the possible cases)