How I can merge two different coverage folder?

[AgarkovRoman]

I have a few packages and each of them has own coverage folder. I want to merge them
How I can do it?
Or maybe there is a better solution? (To have one coverage folder and update it with every new package coverage)

Btw, I am using Istanbul

[AriPerkkio]

If the packages are in a monorepo you should use Vitest's workspaces. It will merge the coverage reports out-of-the-box for whole project.

If these are completely separate projects and for some reason you want to merge the coverage reports, you could use nyc for it, e.g. nyc merge: https://github.com/istanbuljs/nyc#combining-reports-from-multiple-runs

[AriPerkkio]

I think this one is it.

When you are merging reports from Playwright, make sure you are not mixing Istanbul and V8 reports. Use Istanbul on Playwright (instead of Chromium's V8) when using Istanbul on Vitest.

Here's equivalent guide for Jest: https://rafaelalmeidatk.com/blog/merging-coverage-reports-from-jest-and-cypress. Looks like it's using same json reporter.

[fkrauthan]

Oh sorry never mind somehow when I quickly looked at it it looked completely different but I should have looked at the full file. Yeah I think using json reporter should work.

[alanskovrlj]

@AriPerkkio I'm trying to achieve the same result using Vitest's workspaces, but it still seems to generate separate coverage reports for each package instead of merging them and I couldn’t find anything related to this in the documentation. Are there any examples where this is achieved out of the box?

[AriPerkkio]

@alanskovrlj here's one example https://stackblitz.com/~/edit/vitest-workspace-coverage

[alanskovrlj]

@AriPerkkio Thanks! My mistake, I realized I was running vitest command for each package in a loop instead from monorepo root. Anyway, works nicely now 😃