fix: use Teleport with disabled=true instead of stub

[victor141516]

fixes #2628

cc @Alevagre7

As part of #1889 the child of Teleport is wrapped with an arrow function. This aligns with how Vue expects it (that's why we don't have the warning anymore). However the stub doesn't use the same implementation for the Teleport as Vue does: Vue doesn't render the children, but waits for the Teleport component to be mounted, then render the children in the teleport target element.

Instead of using a stub, we have a proposal to utilize the disabled prop from the Vue API for the Teleport component (https://vuejs.org/guide/built-ins/teleport#disabling-teleport) instead of creating a custom stub for it.

By using the official API, we can rely on native functionality rather than introducing a stub, which can lead to more friction and increase the likelihood of errors. The disabled prop allows us to effectively "disable" the teleport behavior, which aligns with the intent behind stubbing—removing specific behavior from the unit test.

In essence, whenever someone creates a stub for a component, the goal is typically to abstract away its behavior during testing. Using the disabled prop achieves the same outcome in a cleaner and more reliable manner.

The implementation may not be the best, so @cexbrayat if you have suggestions for it we can change it.

Thanks!

[netlify]

✅ Deploy Preview for vue-test-utils-docs ready!

Name	Link
🔨 Latest commit	cda399f
🔍 Latest deploy log	https://app.netlify.com/sites/vue-test-utils-docs/deploys/67d30d8b0d7a6c000871749a
😎 Deploy Preview	https://deploy-preview-2632--vue-test-utils-docs.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site configuration.

[cexbrayat]

Thanks for looking into this @victor141516

The idea is interesting but I think we shouldn't lose the teleport-stub element, to be more aligned with all the other stubs. I guess it would be fine if the result was:

<teleport-stub to="body">
    <!--teleport start-->
    <div id="count">1</div>
    <!--teleport end-->
</teleport-stub>

Even if that might already be breaking for some people, I suppose we could live with that.

Or maybe we have a better alternative: we could provide a TeleportStub that does exactly what you suggest, which would be similar to what we do with RouterLinkStub (see https://github.com/vuejs/test-utils/blob/main/src/components/RouterLinkStub.ts). People would then use it like:

const wrapper = mount(Component, {
  global: {
    stubs: {
      Teleport: TeleportStub,
    },
  },
})

I think this could be a good option. Would that be enough for your use-case?

[victor141516]

Hey @cexbrayat thanks for the feedback!

Okay let's go with the better alternative :D

So if I understood correctly, you are suggesting that:

1. If stubs.Teleport === false then nothing is stubbed
2. If stubs.Teleport === true then it's stubbed using the createStub function
3. If stubs.Teleport === TeleportStub then it'll use the aforementioned TeleportStub

Is that right?

[cexbrayat]

Yes, exactly.

VTU will just have to offer the TeleportStub, and developers can opt-in when needed.