fix(reporter): allow dot reporter to work in non interactive terminals

[bstephen1]

Description

Updates dot reporter to support non-TTY terminals instead of silently switching to basic reporter. Closes #3932

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[AriPerkkio]

We definitely do not want to make changes to logger.ts just for dot reporter.

Instead, the dot reporter should maybe print multiple test results at once instead of one-by-one, when in non-TTY.

[bstephen1]

I don't think there's a way to ensure the next console log will print with a prepending newline unless there's a wrapper like that in the logger to determine if the last write was a dot. If you print all the tests in a module at once then the next console log will still print on the same line since writing dots will never include a newline. The only way to avoid it completely would be to print all the tests at once at the end, where you could explicitly add the newline since the tests are done.

I would assume if you're running the dot reporter in CI you probably are suppressing console logs to have minimal output so I'm not sure if it would really be an issue to print them on the same line. I would think the typical output would just be the dots if everything passed. I tried it with the playwright dot reporter and it prints console logs inline too.

[AriPerkkio]

We should not try to intercept the console logs at all here. Instead, let's not write test results one-by-one on onTestCaseResult - let's instead write test cases in batches at onTestModuleEnd.

Removing this isTTY condition should make the reporter print tests as soon as there are enough finished tests to fill a single terminal row:

vitest/packages/vitest/src/node/reporters/dot.ts

Lines 80 to 87 in c00983c

	onTestModuleEnd(testModule: TestModule): void {
	super.onTestModuleEnd(testModule)
	if (!this.isTTY) {
	return
	}
	const columns = this.ctx.logger.getColumns()

[bstephen1]

Is that worth the tradeoff of not printing tests as they come in? You won't be able to check in on the test runner as it's running. It can take a long time to get through a whole row of dots, especially if you're testing browser code. You might not even have enough tests for a full row of dots.

I did some demos with other dot reporters and I couldn't find any that work like that. They all print tests as they finish and either print console logs in line or don't print them at all.

node -- ignores all console logs

mocha -- prints inline

cypress -- ignores all console logs

playwright -- prints inline

japa -- prints inline

I would propose the behavior from the first commit that doesn't touch the logger, prints tests as they finish, and has no extra handling for console logs.

[AriPerkkio]

I would propose the behavior from the first commit that doesn't touch the logger, prints tests as they finish, and has no extra handling for console logs.

Yeah, you are right. There's no easy way to make this work perfectly. When we rewrote Vitest's reporters, this part was something we spent a lot of time optimizing in. But that was just for the TTY mode where we can control the terminal completely.

Let's do this how it was in the first commit. It seems to be inline with other test runners. Thanks for testing other tools too! 💯

[AriPerkkio]

Looks good, thanks for the PR @bstephen1! 🎉