[litinskii]

Summary:

Reproducer for #59353, in the RNTester Playground format requested by the issue bot. This PR changes only packages/rn-tester/js/examples/Playground/RNTesterPlayground.js; it does not fix Modal or change native code.

On the affected Android edge-to-edge configuration, a fresh core Modal reports a full-size child's initial height excluding system insets, followed by the actual full dialog height. The previously measured Pixel 8 API 35 / RN 0.87.1 setup reports 816 -> 914.2857 dp.

The example opens a plain Modal with both translucent props, animationType=none, and a full-size View. It retains every onLayout height in the UI and logs each layout, so the incorrect first measurement remains observable after the second layout. Closing and opening mounts a fresh Modal. There are no timers, animations, manual remeasurement calls, images, Copilot or external dependencies.

Changelog:

[INTERNAL] [ADDED] - Add an RNTester Playground reproducer for Android edge-to-edge Modal initial layout measurements.

Test Plan:

Static checks completed

• Formatted/checked this file using Prettier 3.9.4 with the repository's Flow formatting options: passed.
• Transformed this file using the installed React Native Babel preset: passed.
• Confirmed the diff contains only RNTesterPlayground.js.

A full RNTester Android build, repository-wide ESLint and Flow checks have not been run in this session. The earlier native A/B results described in #59353 were collected with equivalent core Modal/View probes in an RN 0.87.1 app; they are not presented as a runtime test of this PR on current main.

Manual reproduction

1. Check out this PR in a React Native checkout and install dependencies with the repository's pinned Yarn. Build codegen once with yarn --cwd packages/react-native-codegen build.
2. Start Metro from the repository root with yarn start.
3. Build/install RNTester on Android with edge-to-edge enabled, for example:

   ./gradlew :packages:rn-tester:android:app:installDebug -PreactNativeArchitectures=arm64-v8a -PedgeToEdgeEnabled=true

4. Launch RNTester on a portrait Android API 35 emulator with three-button navigation and open Playground.
5. Press Open Modal. Read Every onLayout height in the modal or the Modal onLayout: entries in React Native DevTools Console. Close and reopen to repeat.
6. On the affected configuration, observe an initial screen-minus-system-insets height followed by the full dialog height (previously 816 -> 914.2857 dp). The expected behavior is that the initial full-size child already matches the actual full modal window; exact numeric heights depend on the device.

Please keep #59353 open: this is the requested reproducer, not the native fix.

[meta-cla]

Hi @litinskii!

Thank you for your pull request and welcome to our community.

Action Required

In order to merge any pull request (code, docs, etc.), we require contributors to sign our Contributor License Agreement, and we don't seem to have one on file for you.

Process

In order for us to review and merge your suggested changes, please sign at https://code.facebook.com/cla. If you are contributing on behalf of someone else (eg your employer), the individual CLA may not be sufficient and your employer may need to sign the corporate CLA.

Once the CLA is signed, our tooling will perform checks and validations. Afterwards, the pull request will be tagged with CLA signed. The tagging process may take up to 1 hour after signing. Please give it that time before contacting us about it.

If you have received this in error or have any questions, please contact us at cla@meta.com. Thanks!

[meta-cla]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Meta Open Source project. Thanks!

[meta-cla]

Thank you for signing our Contributor License Agreement. We can now accept your code for this (and any) Meta Open Source project. Thanks!