test utils coverage report broken for Vue2 projects

[MikeOverbeck]

Version

1.3.0

Reproduction link

github.com

Steps to reproduce

create a vue2 app with Jest unit testing with vue create
add collectCoverage: true in jest.config.js
write a method in the HelloWorld.vue component. Do not write a unit test for it.
yarn test:unit
jest will falsely report 100% code coverage in its reporting.

What is expected?

coverage report under 100% for untested code.

What is actually happening?

While test are running and pass/failing appropriately, none of the code within the export default{} block of components is being counted in the code coverage report, always resulting in a 100% coverage report.

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[MikeOverbeck]

Upgraded @vue/test-utils to 1.3.0 in repo to confirm bug persists with latest version

[lmiller1990]

I think this bug needs to be fixed in Vue Jest, since that's what instruments the code coverage for Jest.

Projects definitely have code coverage working for Vue with Jest, though. I wonder if it's a config issue.

[1amardeep]

Same issue is reported on stackoverflow.
https://stackoverflow.com/questions/72674342/vue-2-coverage-issue-getting-different-behaviour-for-vue-2-and-vue-3

[cpontvieux-systra]

vuejs/vue-jest#480

[ebisbe]

vuejs/vue-jest#480

Reading the comments seems the issue is not here. Closing for now.