Functional template can't be mounted

Version

1.0.0-beta.10

Reproduction link

https://github.com/noamcore/functional-template

Steps to reproduce

git clone https://github.com/noamcore/functional-template.git
cd functional-template
npm install
npm run unit

What is expected?

The component can be tested using <template functional/>.

What is actually happening?

Error saying that mount.context can only be used when mounting a functional component

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Functional component using functional attribute on template is on Vue 2.5.0 .

[LinusBorg]

Does that only happen when the functional component is a completely empty one like yours?

[LinusBorg]

Hm, I think this rather is a problem with vue-jest. vue-test-utils never gets to see the <template> element as that's converted when impotrting the component into the test file. So vue-jest has to make sure that functional: true is set on that component's options. However it seems that vue-jest does something different, namely kind of converting a functional component into a "normal" one....

https://github.com/eddyerburgh/vue-jest/blob/master/lib/process.js#L30-L38

/cc @eddyerburgh

[eddyerburgh]

Thanks for the bug report 🙂

Could you please open this issue in vue-jest? As @LinusBorg says, this needs to be fixed there