MacOS test app and fix hermes vendoring from `react-native-macos` #297

kraenhansen · 2025-10-27T22:17:52Z

Merging this PR will:

Use the caller-stack when patching hermes as a heuristics for determining the correct value to pass into --react-native-package - fixing Support vendoring Hermes for out-of-tree platforms #270
Remove a restriction in the Host package Podspec limiting this to iOS in a specific version - since we don't really depend on the iOS SDK, I believe we can remove the limitation entirely.
Add script to init a MacOS test app
Add a job in the check workflow to initialize and build the MacOS test app - fixing Initialize and run a MacOS test app on CI #296

Note how the CI job prints this while pod installing:

[Node-API] Using overridden Hermes in "/Users/runner/work/react-native-node-api/react-native-node-api/apps/macos-test-app/node_modules/react-native-macos/sdks/node-api-hermes"

Copilot

Pull Request Overview

This PR adds support for macOS test apps by introducing initialization scripts, CI workflow integration, and fixes for React Native macOS compatibility. The changes enable automated testing on macOS and improve Hermes vendoring detection for react-native-macos.

Key Changes:

Added macOS test app initialization script with React Native macOS template setup
Implemented caller stack inspection in Ruby script to automatically detect react-native vs react-native-macos
Refactored XCFramework slice selection to use prioritized fallback lists instead of single hardcoded paths

Reviewed Changes

Copilot reviewed 7 out of 9 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tsconfig.scripts.json	New TypeScript configuration for scripts directory
scripts/init-macos-test-app.ts	Script to initialize and configure a React Native macOS test application
packages/host/scripts/patch-hermes.rb	Added automatic detection of React Native package type using caller stack
packages/ferric/src/cargo.ts	Changed XCFramework slice mapping from single values to prioritized arrays with fallback logic
package.json	Added init-macos-test-app script and read-pkg dependency
.github/workflows/check.yml	Added macOS test job with label-based triggering
.changeset/silly-mice-warn.md	Changeset documenting Hermes vendoring fix for macOS

Copilot · 2025-10-28T00:09:27Z

.github/workflows/check.yml

+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: lts/jod


Corrected spelling of 'jod' to 'iron'. The Node.js LTS codename should be 'iron'.

Copilot · 2025-10-28T00:09:28Z

scripts/init-macos-test-app.ts

+    // "--platform-name",
+    // "react-native-macos",


Commented-out code should be removed. If these options were used during development but are no longer needed, they should be deleted rather than left as comments.

Suggested change

// "--platform-name",

// "react-native-macos",

kraenhansen · 2025-10-28T16:24:22Z

Drafting again as I'll attempt to include running the tests in this PR as well. I believe I'm pretty far, while having difficulties initializing the host TurboModule 🤔

I'm experiencing issues (TurboModuleRegistry.getEnforcing throwing) while registering and initializing a TurboModule using the registerCxxModuleToGlobalModuleMap util from ReactCommon/react/nativemodule/core/ReactCommon/CxxTurboModuleUtils.cpp and I started wondering if this code in ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModuleManager.mm is ran by React Native MacOS? I have Hermes and Fabric enabled in the app, if that makes a difference.

kraenhansen · 2025-10-28T18:35:21Z

@copilot can you add the missing x86_64 Darwin Rust target currently failing the build. I expect this will take just a single step with a single rustup command. Keep it brief, no comments in the workflow. Add only the missing target, nothing more and get some inspiration from how the other targets are added in other jobs of the workflow.

Copilot · 2025-10-28T18:35:35Z

@kraenhansen I've opened a new pull request, #298, to work on those changes. Once the pull request is ready, I'll request review from you.

Copilot

Pull Request Overview

Copilot reviewed 22 out of 25 changed files in this pull request and generated 2 comments.

Copilot · 2025-11-01T15:49:28Z

scripts/init-macos-test-app.ts

+    premacos: "killall 'MacOSTestApp' || true",
+    macos: "react-native run-macos --no-packager",
+    test: "mocha-remote --exit-on-error -- concurrently --passthrough-arguments --kill-others-on-fail npm:metro 'npm:macos -- {@}' --",
+    "test:allTests": "MOCHA_REMOTE_CONTEXT=allTests node --run test:ios -- ",


The script reference 'test:ios' appears incorrect for a macOS test app. This should likely be 'test:macos' or just 'test' to match the other test scripts defined in this file.

Suggested change

"test:allTests": "MOCHA_REMOTE_CONTEXT=allTests node --run test:ios -- ",

"test:allTests": "MOCHA_REMOTE_CONTEXT=allTests node --run test -- ",

Pushed a fix for this 👍

Copilot · 2025-11-01T15:49:29Z

packages/host/src/node/cli/apple.ts

+  if (fs.existsSync(versionAPath) && !fs.existsSync(versionCurrentPath)) {
+    await fs.promises.symlink(
+      path.relative(path.dirname(versionCurrentPath), versionAPath),
+      versionCurrentPath,
+    );
+  }
+
+  const { CFBundleExecutable } = await readFrameworkInfo(
+    path.join(frameworkPath, "Versions", "Current", "Resources", "Info.plist"),
+  );
+


The code creates the 'Current' symlink on line 204-207, then immediately uses it on line 211 to read the Info.plist. However, if the symlink didn't exist before and was just created, the Info.plist path should use 'A' instead of 'Current', or the readFrameworkInfo call should occur before attempting to restore any symlinks.

Suggested change

if (fs.existsSync(versionAPath) && !fs.existsSync(versionCurrentPath)) {

await fs.promises.symlink(

path.relative(path.dirname(versionCurrentPath), versionAPath),

versionCurrentPath,

);

}

const { CFBundleExecutable } = await readFrameworkInfo(

path.join(frameworkPath, "Versions", "Current", "Resources", "Info.plist"),

);

let symlinkJustCreated = false;

if (fs.existsSync(versionAPath) && !fs.existsSync(versionCurrentPath)) {

await fs.promises.symlink(

path.relative(path.dirname(versionCurrentPath), versionAPath),

versionCurrentPath,

);

symlinkJustCreated = true;

}

// If we just created the symlink, use the real path to Info.plist; otherwise, use the symlink path

const infoPlistPath = symlinkJustCreated

? path.join(frameworkPath, "Versions", "A", "Resources", "Info.plist")

: path.join(frameworkPath, "Versions", "Current", "Resources", "Info.plist");

const { CFBundleExecutable } = await readFrameworkInfo(infoPlistPath);

Enable Hermes and Fabric Patch react_native_post_install to pass react native path Don't pod install when initializing Patch macos app with scripts and source files Re-arm the init script Move linked deps into install command to make --install-links effective Using regular linking for monorepo deps Include original dependencies Enable new arch in Podfile Fix comment from review

No need to Setup Android SDK Debugging with Copilot Pass --mode when building from CLI Install CMake 3.22 Fix bootstrap issue Trying a higher CMake version Remove debug info from workflow Build universal Darwin libraries Add missing x86_64-apple-darwin Rust target to macOS CI job (#298) * Initial plan * Add missing x86_64-apple-darwin Rust target to macOS job Co-authored-by: kraenhansen <[email protected]> * Add only missing x86_64-apple-darwin target (aarch64 is host) Co-authored-by: kraenhansen <[email protected]> --------- Co-authored-by: copilot-swe-agent[bot] <[email protected]> Co-authored-by: kraenhansen <[email protected]> Run MacOS test app Use package script to run all tests

Copilot

Pull Request Overview

Copilot reviewed 9 out of 12 changed files in this pull request and generated 3 comments.

Copilot · 2025-11-02T18:39:58Z

.github/workflows/check.yml

+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version: lts/jod


Corrected spelling of 'jod' to 'jod' - this appears to be a typo for 'iron' (the current Node.js LTS codename).

@copilot you seem to be outdated on the name of the latest active LTS, please read https://nodejs.org/en/blog/release/v22.11.0 and update your instructions with a brief comment to ensure you won't make that mistake again.

Copilot · 2025-11-02T18:39:58Z

packages/host/scripts/patch-hermes.rb

+
 if ENV['REACT_NATIVE_OVERRIDE_HERMES_DIR'].nil?
-  VENDORED_HERMES_DIR ||= `npx react-native-node-api vendor-hermes --silent '#{Pod::Config.instance.installation_root}'`.strip
+  VENDORED_HERMES_DIR ||= `npx react-native-node-api vendor-hermes --react-native-package '#{get_react_native_package()}' --silent '#{Pod::Config.instance.installation_root}'`.strip


The method call uses unnecessary parentheses. In Ruby, get_react_native_package() should be written as get_react_native_package when calling methods without arguments.

Suggested change

VENDORED_HERMES_DIR ||= `npx react-native-node-api vendor-hermes --react-native-package '#{get_react_native_package()}' --silent '#{Pod::Config.instance.installation_root}'`.strip

VENDORED_HERMES_DIR ||= `npx react-native-node-api vendor-hermes --react-native-package '#{get_react_native_package}' --silent '#{Pod::Config.instance.installation_root}'`.strip

Copilot · 2025-11-02T18:39:58Z

scripts/init-macos-test-app.ts

+  console.log("Copying source files from test-app into macos-test-app:");
+  const FILE_NAMES = [
+    "App.tsx",
+    // Adds the babel plugin needed to transform require calls
+    "babel.config.js",
+    // Adds the ability to reference symlinked packages


[nitpick] The comment on line 170-172 mentions 'Adds the babel plugin' and 'Adds the ability', but these describe what the files do rather than why they're being copied. The console.log could be more specific about which test-app (iOS) the files are being copied from.

Suggested change

console.log("Copying source files from test-app into macos-test-app:");

const FILE_NAMES = [

"App.tsx",

// Adds the babel plugin needed to transform require calls

"babel.config.js",

// Adds the ability to reference symlinked packages

console.log(`Copying source files from ${OTHER_APP_PATH} into ${APP_PATH}:`);

const FILE_NAMES = [

// Ensure macos-test-app uses the same entry point as test-app

"App.tsx",

// Ensure macos-test-app uses the same Babel config as test-app (for require transformation)

"babel.config.js",

// Ensure macos-test-app uses the same Metro config as test-app (for symlinked packages)

Copilot · 2025-11-02T18:50:18Z

@kraenhansen I've opened a new pull request, #306, to work on those changes. Once the pull request is ready, I'll request review from you.

kraenhansen self-assigned this Oct 27, 2025

kraenhansen force-pushed the kh/macos-test-app branch from ea60bd0 to 4f1711e Compare October 27, 2025 22:18

kraenhansen requested a review from shirakaba October 27, 2025 22:19

This was linked to issues Oct 27, 2025

Support vendoring Hermes for out-of-tree platforms #270

Closed

Initialize and run a MacOS test app on CI #296

Closed

kraenhansen marked this pull request as ready for review October 27, 2025 23:36

kraenhansen requested a review from Copilot October 28, 2025 00:08

Copilot AI reviewed Oct 28, 2025

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kraenhansen force-pushed the kh/macos-test-app branch 3 times, most recently from ecb0fee to ab26a44 Compare October 28, 2025 10:48

kraenhansen marked this pull request as draft October 28, 2025 16:22

Copilot AI mentioned this pull request Oct 28, 2025

Add missing x86_64-apple-darwin Rust target to macOS CI job #298

Merged

kraenhansen force-pushed the kh/macos-test-app branch 2 times, most recently from 063b11e to bd42182 Compare October 30, 2025 05:49

kraenhansen marked this pull request as ready for review November 1, 2025 15:48

kraenhansen requested a review from Copilot November 1, 2025 15:48

Copilot AI reviewed Nov 1, 2025

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kraenhansen force-pushed the kh/macos-test-app branch from f40d5ce to 57496a5 Compare November 1, 2025 17:15

kraenhansen mentioned this pull request Nov 2, 2025

Warn on "pod install" with the new architecture disabled #300

Merged

kraenhansen force-pushed the kh/macos-test-app branch from 57496a5 to edb09ca Compare November 2, 2025 12:13

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Remove platform restriction from host package's podspec

1adf988

kraenhansen added 4 commits November 2, 2025 19:36

Add fallback for watchFolders in the metro config

97c5c36

Update Podspec to detect React Native package name

f83c5c5

kraenhansen force-pushed the kh/macos-test-app branch from edb09ca to 02ae255 Compare November 2, 2025 18:37

kraenhansen requested a review from Copilot November 2, 2025 18:39

Copilot AI reviewed Nov 2, 2025

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Copilot AI mentioned this pull request Nov 2, 2025

Document Node.js LTS version in copilot instructions #306

Draft

kraenhansen merged commit a2fd422 into main Nov 2, 2025
9 checks passed

kraenhansen deleted the kh/macos-test-app branch November 2, 2025 19:30

	"test:allTests": "MOCHA_REMOTE_CONTEXT=allTests node --run test:ios -- ",
	"test:allTests": "MOCHA_REMOTE_CONTEXT=allTests node --run test -- ",

	VENDORED_HERMES_DIR \|\|= `npx react-native-node-api vendor-hermes --react-native-package '#{get_react_native_package()}' --silent '#{Pod::Config.instance.installation_root}'`.strip
	VENDORED_HERMES_DIR \|\|= `npx react-native-node-api vendor-hermes --react-native-package '#{get_react_native_package}' --silent '#{Pod::Config.instance.installation_root}'`.strip

MacOS test app and fix hermes vendoring from react-native-macos #297

MacOS test app and fix hermes vendoring from react-native-macos #297

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MacOS test app and fix hermes vendoring from `react-native-macos` #297

MacOS test app and fix hermes vendoring from `react-native-macos` #297

kraenhansen commented Oct 27, 2025 •

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