Addon Test: Correctly stop Storybook when Vitest closes

[JReinhold]

Closes #28890

What I did

Noticed that when we start Storybook as part of running Vitest, Storybook contains a nested list of 3 child processes. So when the Storybook process was killed at the end of a Vitest run, only the root SB process was killed, and the rest stayed alive, including the one that actually listens on the port.

Using node-tree-kill to kill the entire process tree fixed the issue.

I'm not a huge fan of the solution, I'd rather like to understand why Storybook has multiple child processes, and figure out why they aren't killed when the root process is killed. But I couldn't find anywhere in the code where we explicitly spawn new child processes.

EDIT: 👆 We figured it out. Storybook doesn't have multiple processes, but when doing spawn('yarn storybook dev', { shell: true }), it spawns a process for Yarn, which spawns a node process with with Storybook, which is why there are multiple nested processes.

Checklist for Contributors

Testing

1. Create a sandbox in the monorepo
2. Ensure no Storybook is already running
3. Go into it and run yarn vitest run Button
4. Run lsof -i :6006
5. You shouldn't see any output because no process should still be listening on port 6006 when the tests are done.

The changes in this PR are covered in the following automated tests:

• stories
• unit tests
• integration tests
• end-to-end tests

Manual testing

This section is mandatory for all contributions. If you believe no manual test is necessary, please state so explicitly. Thanks!

Documentation

• Add or update documentation reflecting your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Checklist for Maintainers

• When this PR is ready for testing, make sure to add ci:normal, ci:merged or ci:daily GH label to it to run a specific set of sandboxes. The particular set of sandboxes can be found in code/lib/cli-storybook/src/sandbox-templates.ts

• Make sure this PR contains one of the labels below:

  Available labels

  • bug: Internal changes that fixes incorrect behavior.
  • maintenance: User-facing maintenance tasks.
  • dependencies: Upgrading (sometimes downgrading) dependencies.
  • build: Internal-facing build tooling & test updates. Will not show up in release changelog.
  • cleanup: Minor cleanup style change. Will not show up in release changelog.
  • documentation: Documentation only changes. Will not show up in release changelog.
  • feature request: Introducing a new feature.
  • BREAKING CHANGE: Changes that break compatibility in some way with current major version.
  • other: Changes that don't fit in the above categories.

🦋 Canary release

This PR does not have a canary release associated. You can request a canary release of this pull request by mentioning the @storybookjs/core team here.

core team members can create a canary release here or locally with gh workflow run --repo storybookjs/storybook canary-release-pr.yml --field pr=<PR_NUMBER>

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createSize	0 B	0 B	0 B	-	-
generateSize	77.7 MB	77.7 MB	26.8 kB	8.09	0%
initSize	133 MB	133 MB	26.8 kB	1.02	0%
diffSize	55.1 MB	55.1 MB	0 B	1	0%
buildSize	6.87 MB	6.87 MB	0 B	0.51	0%
buildSbAddonsSize	1.51 MB	1.51 MB	0 B	1.04	0%
buildSbCommonSize	195 kB	195 kB	0 B	-	0%
buildSbManagerSize	1.86 MB	1.86 MB	0 B	1.22	0%
buildSbPreviewSize	0 B	0 B	0 B	-	-
buildStaticSize	0 B	0 B	0 B	-	-
buildPrebuildSize	3.57 MB	3.57 MB	0 B	1.16	0%
buildPreviewSize	3.3 MB	3.3 MB	0 B	0.45	0%
testBuildSize	0 B	0 B	0 B	-	-
testBuildSbAddonsSize	0 B	0 B	0 B	-	-
testBuildSbCommonSize	0 B	0 B	0 B	-	-
testBuildSbManagerSize	0 B	0 B	0 B	-	-
testBuildSbPreviewSize	0 B	0 B	0 B	-	-
testBuildStaticSize	0 B	0 B	0 B	-	-
testBuildPrebuildSize	0 B	0 B	0 B	-	-
testBuildPreviewSize	0 B	0 B	0 B	-	-

name	before	after	diff	z	%
createTime	7.8s	22s	14.1s	2.9	🔺64.4%
generateTime	19.2s	20.2s	937ms	-0.06	4.6%
initTime	12.3s	13.1s	831ms	-0.24	6.3%
buildTime	9s	8.7s	-246ms	-0.62	-2.8%
testBuildTime	0ms	0ms	0ms	-	-
devPreviewResponsive	5.3s	4.2s	-1s -64ms	-1.37	🔰-25.1%
devManagerResponsive	3.8s	3.1s	-723ms	-1.49	🔰-22.8%
devManagerHeaderVisible	530ms	452ms	-78ms	-1.62	🔰-17.3%
devManagerIndexVisible	560ms	479ms	-81ms	-1.52	🔰-16.9%
devStoryVisibleUncached	1.8s	1.7s	-86ms	-0.13	-5%
devStoryVisible	593ms	525ms	-68ms	-1.11	-13%
devAutodocsVisible	496ms	419ms	-77ms	-1.47	🔰-18.4%
devMDXVisible	506ms	421ms	-85ms	-1.34	🔰-20.2%
buildManagerHeaderVisible	587ms	486ms	-101ms	-1.09	-20.8%
buildManagerIndexVisible	665ms	574ms	-91ms	-1.07	-15.9%
buildStoryVisible	527ms	451ms	-76ms	-1.06	-16.9%
buildAutodocsVisible	461ms	370ms	-91ms	-1.43	🔰-24.6%
buildMDXVisible	442ms	361ms	-81ms	-1.62	🔰-22.4%

Greptile Summary

Added the tree-kill package to properly terminate all Storybook child processes when running with Vitest, replacing the previous process termination logic in global-setup.ts with a more robust solution.

• Added tree-kill dependency in code/addons/test/package.json for process tree termination
• Modified code/addons/test/src/vitest-plugin/global-setup.ts to use tree-kill for complete process cleanup
• Fixes issue where child Storybook processes remained alive after Vitest completion
• Addresses port 6006 remaining occupied after test runs

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[greptile-apps]

_{2 file(s) reviewed, 2 comment(s)
Edit PR Review Bot Settings | Greptile}

[greptile-apps]

logic: error message is incomplete - should include the actual error details

[storybook-pr-benchmarking]

Package Benchmarks

^{Commit: 3e51714, ran on 10 December 2024 at 21:59:00 UTC}

The following packages have significant changes to their size or dependencies:

@storybook/angular

	Before	After	Difference
Dependency count	259	259	0
Self size	362 KB	362 KB	0 B
Dependency size	34.54 MB	34.56 MB	🚨 +23 KB 🚨
Bundle Size Analyzer	Link	Link