Portable stories: Fix playwright CT to allow functions to be passed as props

[adamscybot]

Closes #31150

What I did

#31150 details the proposed fix. Essentially, we do not need to pass the props to the page to perform the storybook load/play steps, which are wrapped in page.evaluate(). They are extraneous. Passing them here is a problem since they have to be serialisable to go through page.evalaute() and functions are not, which prevents useful playwright CT native functionality that allows functions to be passed from tests.

So by omitting them from being passed to the page.evaluate() calls in the first place, but retaining them when calling the real "mount" function, we get the desired native functionality without disrupting storybook.

Checklist for Contributors

Testing

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

• stories
• unit tests
• integration tests --> or whatever the portable stories kitchen sink tests are classified as 🙂
• end-to-end tests

Manual testing

None needed as this would be exactly the same as doing what I have added to the "renders story with props" portable stories kitchen sink test. Essentially, just pass a function from a playwright test to a portable story, and check that it actually works.

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>

Greptile Summary

Fixed Playwright component testing to properly handle function props in portable stories by modifying the serialization process.

• Separated props from story reference before page.evaluate() calls to avoid function serialization issues
• Modified createPlaywrightTest to maintain full props for Playwright's mount function while excluding them from browser evaluation
• Added test case in test-storybooks/portable-stories-kitchen-sink/react/stories/Button.playwright.tsx to verify function prop handling
• Fixed regression where function event handlers couldn't be passed from test files
• Ensures compatibility with Playwright's native component testing functionality

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[greptile-apps]

LGTM

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[greptile-apps]

LGTM

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[adamscybot]

Hi @valentinpalkovic , @yannbf . Sorry for the annoying ping.

Would it be possible to take a look at this? I'm back in this area now and it would be great to get rid of my horrible patches :). We've been running this fix for a little while now with quite a substantial number of tests on top of it with no problems thus far.

[greptile-apps]

LGTM

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[storybook-app-bot]

Package Benchmarks

^{Commit: a824e72, ran on 30 June 2025 at 15:28:23 UTC}

No significant changes detected, all good. 👏

[yannbf]

Thank you so much for your contribution!

[nx-cloud]

View your CI Pipeline Execution ↗ for commit a824e72.

Command	Status	Duration	Result
nx run-many -t build --parallel=3	✅ Succeeded	1m 12s	View ↗

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☁️ Nx Cloud last updated this comment at 2025-07-01 08:45:39 UTC