From e47671d0fec67a247e99d42ee34aa5246869b2ab Mon Sep 17 00:00:00 2001
From: Saad Najmi <sanajmi@microsoft.com>
Date: Wed, 16 Sep 2026 02:04:42 -0500
Subject: [PATCH 1/3] fix(hermes): resolve prebuild artifacts from version
 metadata


From eae403538514aa2f25f6c92f858afa3b86916e56 Mon Sep 17 00:00:00 2001
From: Saad Najmi <sanajmi@microsoft.com>
Date: Wed, 16 Sep 2026 02:04:43 -0500
Subject: [PATCH 2/3] fix(ci): pass Hermes subgroup to snapshot URL resolver

---
 .../__tests__/resolve-hermes-url.test.mjs     | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 .github/scripts/__tests__/resolve-hermes-url.test.mjs

diff --git a/.github/scripts/__tests__/resolve-hermes-url.test.mjs b/.github/scripts/__tests__/resolve-hermes-url.test.mjs
new file mode 100644
index 00000000000..6b368d24779
--- /dev/null
+++ b/.github/scripts/__tests__/resolve-hermes-url.test.mjs
@@ -0,0 +1,56 @@
+import assert from 'node:assert/strict';
+import {readFileSync} from 'node:fs';
+import {createRequire, stripTypeScriptTypes} from 'node:module';
+import {test} from 'node:test';
+import {runInNewContext} from 'node:vm';
+
+const callerSource = readFileSync(new URL('../resolve-hermes.mts', import.meta.url), 'utf8');
+const helperSource = readFileSync(new URL(
+  '../../../packages/react-native/scripts/ios-prebuild/utils.js', import.meta.url,
+), 'utf8');
+// Execute the actual downloader without the CLI dispatch or the zx dependency.
+const downloaderSource = stripTypeScriptTypes(callerSource.slice(
+  callerSource.indexOf('async function downloadUpstreamHermesTarball('),
+  callerSource.indexOf('/**\n * Extracts an upstream Hermes tarball'),
+));
+
+for (const buildType of ['Debug', 'Release']) {
+  for (const metadataAvailable of [true, false]) {
+    test(`${buildType}: ${metadataAvailable ? 'resolves nightly metadata' : 'missing metadata keeps release fallback'}`, async () => {
+      const version = buildType === 'Debug' ? '123.4.5' : '987.6.5';
+      const flavor = buildType.toLowerCase();
+      const snapshotRoot = `https://central.sonatype.com/repository/maven-snapshots/com/facebook/hermes/hermes-ios/${version}-SNAPSHOT`;
+      const metadataUrl = `${snapshotRoot}/maven-metadata.xml`;
+      const releaseUrl = `https://repo1.maven.org/maven2/com/facebook/hermes/hermes-ios/${version}/hermes-ios-${version}-hermes-ios-${flavor}.tar.gz`;
+      const nightlyUrl = `${snapshotRoot}/hermes-ios-${version}-20260915.123456-7-hermes-ios-${flavor}.tar.gz`;
+      const requests = [];
+      const fetch = async url => {
+        requests.push(url);
+        if (url === metadataUrl && metadataAvailable) {
+          return {
+            ok: true,
+            text: async () => '<metadata><versioning><snapshot><timestamp>20260915.123456</timestamp><buildNumber>7</buildNumber></snapshot></versioning></metadata>',
+          };
+        }
+        return {ok: false, status: 404, statusText: 'Not Found'};
+      };
+      const module = {exports: {}};
+      runInNewContext(helperSource, {
+        module,
+        require: createRequire(import.meta.url),
+        fetch,
+      });
+      const download = runInNewContext(`${downloaderSource}\ndownloadUpstreamHermesTarball`, {
+        computeNightlyTarballURL: module.exports.computeNightlyTarballURL,
+        resolveHermesArtifactVersion: () => version,
+        fetch,
+        echo: () => {},
+      });
+
+      assert.equal(await download(buildType), null);
+      assert.deepEqual(requests, metadataAvailable
+        ? [metadataUrl, releaseUrl, nightlyUrl]
+        : [metadataUrl, releaseUrl]);
+    });
+  }
+}

From b62db850f25001644390d8836706b2a9ad92f1d0 Mon Sep 17 00:00:00 2001
From: Saad Najmi <sanajmi@microsoft.com>
Date: Tue, 22 Sep 2026 18:46:34 -0700
Subject: [PATCH 3/3] fix(ci): align Flow annotations and Jest configuration

Apply the independently reviewed branch-specific CI follow-up while preserving public-registry locks and the linear stack.
---
 scripts/js-api/build-types/buildApiSnapshot.js              | 2 +-
 .../typescript/canonicalizeLocalPackageImports.js           | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/js-api/build-types/buildApiSnapshot.js b/scripts/js-api/build-types/buildApiSnapshot.js
index e60d756c57a..cbbe5b4fbe6 100644
--- a/scripts/js-api/build-types/buildApiSnapshot.js
+++ b/scripts/js-api/build-types/buildApiSnapshot.js
@@ -254,7 +254,7 @@ async function rewriteLocalImports(
 async function getProcessedSnapshotResult(
   tempDirectory: string,
   options: BuildApiSnapshotOptions,
-  packages: $ReadOnlyArray<{directory: string, name: string}>,
+  packages: ReadonlyArray<{directory: string, name: string}>,
 ): Promise<string> {
   const rollupPath = path.join(
     tempDirectory,
diff --git a/scripts/js-api/build-types/transforms/typescript/canonicalizeLocalPackageImports.js b/scripts/js-api/build-types/transforms/typescript/canonicalizeLocalPackageImports.js
index 9c97ce7f811..2a71455d03f 100644
--- a/scripts/js-api/build-types/transforms/typescript/canonicalizeLocalPackageImports.js
+++ b/scripts/js-api/build-types/transforms/typescript/canonicalizeLocalPackageImports.js
@@ -18,7 +18,7 @@ import type {
 
 function canonicalizeSource(
   source: string,
-  packageNames: $ReadOnlyArray<string>,
+  packageNames: ReadonlyArray<string>,
 ): string {
   if (!source.startsWith('./') && !source.startsWith('../')) {
     return source;
@@ -37,8 +37,8 @@ function canonicalizeSource(
 }
 
 function canonicalizeLocalPackageImports(
-  packageNames: $ReadOnlyArray<string>,
-): PluginObj<mixed> {
+  packageNames: ReadonlyArray<string>,
+): PluginObj<unknown> {
   function canonicalizeNodeSource(
     nodePath: NodePath<
       ExportAllDeclaration | ExportNamedDeclaration | ImportDeclaration,