Documentation on how to use with `vitest shard`

[jak]

Hey,

Thanks for the action - very helpful!

It'd be useful to know how (or if?) this can be used with the multiple outputs from the shard command

[davelosert]

Hey @jak,

unfortunately, I don't know the shard feature just yet (haven't been doing a lot of development with vitest recently), so I would have to look deeper into this. I am not sure when I will be able to do so.

However, I am always happy to accept pull-requests that will document how this works with this library, or enable this library to work with the command. 🙂

Sorry I can't be more helpful right now - time is a rare asset 🕐

[alec-oms]

@jak, did you work this out?

[alec-oms]

After a few days of pain, I have finally worked this out and vitest-coverage-report-action will work with shard command out of the box so long as you get your config right.

When using shard you may think that you don't need coverage enabled whilst you're using reporter=blob, since any other coverage report will only be a partial, but...

If you don't keep coverage enabled then the blob report will not include any coverage information, so when you come to use the --merge-reports command the file coverage-summary.json (required by this action) will have unknown % values and the coverage-final.json will also be empty.

With that in mind, if you follow vitest sharding github example and add then use this action after you've merged the reports, it should all work fingers crossed!

[gushecht]

hiya @alec-oms – do you mind sharing your full github action? ty!

[alec-oms]

hiya @alec-oms – do you mind sharing your full github action? ty!

I'm afraid I can't share it all, but essentially it's the example in the Vitest docs with a few extra params included:

For the run tests step:

yarn vitest run --reporter=blob --reporter=default --shard=${{ matrix.shardIndex }}/${{ matrix.shardTotal }} --coverage.enabled=true --coverage.thresholds.lines=0 --coverage.thresholds.functions=0 --coverage.thresholds.branches=0 --coverage.thresholds.statements=0

I've enabled coverage in the vite.config but you can do it inline as above. I've also disabled thresholds inline to prevent it failing threshold checks against a single shard.

For the merge reports step:

yarn vitest run --merge-reports ./.vitest-reports --coverage.reporter=json-summary --reporter=github-actions --reporter=default

It first downloads the blobs (as per the Vitest example). This includes the coverage info for each shard. After the merge-reports it'll also be checking the thresholds against the combined results and alsos reports with the Vitest github-actions too.

Happy to help if I can, and hope this helps.

[gushecht]

thank you so much @alec-oms!

in case helpful for anyone else, i had to add --coverage.enabled=true to the merge-reports command like so

pnpm vitest run --merge-reports ./.vitest-reports --coverage.enabled=true --reporter=github-actions --reporter=default