Running tests in verbose mode with console logging breaks output

[jeysal]

Repro: https://github.com/yldio/yld.io/tree/38514750c72574747c96de405ab0ec174b75692d

yarn add -D [email protected]
yarn test add-frontmatter --reporters=jest-react-reporter 

It also does not show test case details like the default reporter, not sure if it is supposed to do that.

[SimenB]

It also does not show test case details like the default reporter, not sure if it is supposed to do that.

It's supposed to work the exact same, at least for a first iteration. Could you open up a separate issue for it? Or send a PR 🙂

Opened one up: #6

[SimenB]

Haven't tried, but I'm wondering if it's related to vadimdemedes/ink#162

[SimenB]

Testing now, it's something to do with @testing-library/react's async act warning (just a console.error). Deleting that line from node_modules fixes the issue. Not sure why it's not properly intercepted...

[SimenB]

Figured out what's going on, although I have no idea how to fix it...

The issue is that, since we're only running a single test, Jest switches into verbose mode: https://github.com/facebook/jest/blob/18dfcbb41965a6c2682e1235b5f76dd071be24a1/packages/jest-core/src/runJest.ts#L231. Since we're verbose, we use the custom console instead of the buffered one: https://github.com/facebook/jest/blob/18dfcbb41965a6c2682e1235b5f76dd071be24a1/packages/jest-runner/src/runTest.ts#L135-L141. This console writes directly to stderr on log messages, rather than buffering them and relying on the reporter to print it: https://github.com/facebook/jest/blob/18dfcbb41965a6c2682e1235b5f76dd071be24a1/packages/jest-console/src/CustomConsole.ts#L46-L51

There is jestjs/jest#6441 which we should do, but it'll cause log entries to be printed twice... I think the only proper way to solve this is to land jestjs/jest#9001 and also stream individual console entries as they happen.

We don't wanna force people to use the buffered logger, since e.g. tests that time out or hang forever would not get any logging out.

Thoughts? /cc @thymikee @rogeliog

Edit: It means vadimdemedes/ink#162 would help, but I think the issue lies with Jest itself and allowing a stream of data rather than just complete test results should allow us to fix this.

[rogeliog]

Yes, I agree that we might need something like jestjs/jest#9001 and jestjs/jest#6441 would make sense for this.