wrapper.setProps doesn't work on Functional component

[jonnyparris]

Version

1.0.0-beta.11

Reproduction link

https://github.com/jonnyparris/vue-test-utils-mocha-webpack-example/blob/e2e634e4640ce40180b957b4feab51076b77a780/test/Message.spec.js#L19

Steps to reproduce

use setData() as per docs

What is expected?

data should be set

What is actually happening?

data remains unchanged

---

Bug seems to have been introduced somewhere between version beta3 and beta11 (only just upgraded packages across my project)

[eddyerburgh]

There isn't any data in a functional component, so you calling setData will have no effect. We should add error handling to tell the user that they can't call setData on a functional component.

But there is an issue with setProps and functional components. It's going to be tricky to fix.

[jonnyparris]

MessageToggle.vue has a data object - I'm not sure I understand what you mean. Please can you explain?
To clarify on my side, I have a bunch of tests that were working fine using setData that suddenly stop working withe the latest version.
I just forked that example from the docs to both verify it was that method in particular but also to use a minimal example.

[eddyerburgh]

You're calling setData on the wrapper of a functional component. Functional components are stateless, so there's no data to set.

If the tests were previously working correctly with setData, it was because setData was behaving incorrectly.

[jonnyparris]

Thanks & my bad, I thought I was testing MessageToggle but actually it was just the Message component that wrote the spec for.
Adding the same setData spec to MessageToggle passes with beta11 but the prop test that was already in the repo is indeed failing.

I'm going to have to double check my original failing setData tests then 😕

[dimensi]

@eddyerburgh if setProps and setData not working. How set props on functional component?
propsData, not working too

[beyer-martin]

In what state is this?

[eddyerburgh]

It's not being worked on. I think we need a change in core to be able to implement this. I believe we need to have access to the render context, but it's not exposed—https://github.com/vuejs/vue/blob/dev/src/core/vdom/create-functional-component.js#L97.

If you want to look into this, I'd be happy to help.

[artf]

@dimensi you can mount it via context https://vue-test-utils.vuejs.org/api/options.html#context