setData/setProps

[lmiller1990]

As per vuejs/rfcs#151 (comment)

We need to keep setData and setProps. or have something similar. I think only supporting the top level wrapper is fine for now, since we don't have find(Comp) yet.

[afontcu]

While this is something we might end up needing in VTU, what if we released the first alpha(s) of vtu-next without setData, so we can spot the areas where it can be helpful?

Also, I believe there are some technical limitations due to Vue 3 nature – correct me if I'm wrong!

[lmiller1990]

I just released alpha 0 about 10 min ago :D check the README for this repo. I added some info. Feel free to change anything in the README btw. I agree 100% - the sooner we get feedback, the better.

The main reason we don't have it is technical limitations. If it is a critical feature, we may need to add something in core for it. Lucky Vue 3 is still alpha.

Let's chat to Evan and get his opinion. I don't like the idea of changing too much in core for a specific feature for a specific lib. But I also think we have at least some responsibility not to break everyone's tests. I have a feeling most setData usage can be converted to using mounting options (maybe 95% of cases), so maybe it's not a big deal.

[lmiller1990]

So you can hack in your own "setProps" like so:

import { h, reactive } from 'vue'

import { mount } from '../src'

test.only('', async () => {
  const Foo = {
    props: ['foo'],
    template: '<div>{{ foo }}</div>'
  }
  const data = reactive({ 
    foo: 'foo'
  })
  const Wrapper = {
    components: { Foo },
    data() {
      return data
    },
    template: '<div><Foo :foo="foo" /></div>'
  }

  const wrapper = mount(Wrapper)

  console.log(wrapper.html()) //=> '<div>foo</div>
  data.foo = 'bar'
  await wrapper.vm.$nextTick()

  console.log(wrapper.html()) //=> '<div>bar</div>
})

I wonder if we can wrap this nicely. Eg, it might become setProps(wrapper, { foo: bar }). I think it's okay if the API looks a bit different, as long as their is a clear migration path.

I wonder if changing from the "subject verb" style (eg, wrapper.setProps) to "verb subject" (setProps(wrapper)) would make the implementation cleaner.

[lmiller1990]

these are done. setData will be merged in at a later date.