fix(spm): drop the plist npm dependency from flavored-frameworks

flavored-frameworks.js required the `plist` module, which is not a
dependency of the react-native package — it only resolves inside this
monorepo (and in repos like Expo's) via hoisting. In a fresh consumer app
`spm add` failed with "Cannot find module 'plist'". Parse xcframework
Info.plists via `plutil -convert json` instead (the same pattern the
pre-B1 swap script used), with a portable plutil mock in the test suites
for Linux CI and a regression test that loads the module with `plist`
unresolvable.

450 spm tests green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: chrfalch

packages/react-native/scripts/spm/__tests__/flavored-frameworks-plist-dep-test.js

@@ -0,0 +1,101 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ */
+
+'use strict';
+
+// Regression test for the fresh-consumer-app failure: `plist` is NOT a
+// dependency of the react-native package, so it only resolves inside this
+// monorepo via hoisting. A generated app running `spm add` gets
+// "Cannot find module 'plist'". flavored-frameworks.js must therefore never
+// require it — Info.plist parsing goes through plutil instead.
+jest.mock('plist', () => {
+  throw new Error(
+    "Cannot find module 'plist' — flavored-frameworks.js must not depend on it",
+  );
+});
+
+// plutil is macOS-only; stand in with a portable plist-parse so the suite is
+// hermetic on Linux CI. Module-level mock because flavored-frameworks.js
+// destructures execFileSync at require time (same pattern the old
+// swap-flavor-test used).
+jest.mock('child_process', () => {
+  const actual = jest.requireActual('child_process');
+  return {
+    ...actual,
+    execFileSync: (cmd, args, opts) => {
+      if (cmd === 'plutil') {
+        const fs = require('fs');
+        const plist = jest.requireActual('plist');
+        const file = args[args.length - 1];
+        return Buffer.from(
+          JSON.stringify(plist.parse(fs.readFileSync(file, 'utf8'))),
+        );
+      }
+      return actual.execFileSync(cmd, args, opts);
+    },
+  };
+});
+
+const fs = require('fs');
+const os = require('os');
+const path = require('path');
+const realPlist = jest.requireActual('plist');
+
+function makeXcframework(root /*: string */) /*: string */ {
+  const xcframework = path.join(root, 'React.xcframework');
+  const sliceId = 'ios-arm64';
+  fs.mkdirSync(path.join(xcframework, sliceId, 'React.framework'), {
+    recursive: true,
+  });
+  fs.writeFileSync(
+    path.join(xcframework, sliceId, 'React.framework', 'React'),
+    'not-a-real-mach-o',
+  );
+  fs.writeFileSync(
+    path.join(xcframework, 'Info.plist'),
+    realPlist.build({
+      AvailableLibraries: [
+        {
+          LibraryIdentifier: sliceId,
+          LibraryPath: 'React.framework',
+          SupportedPlatform: 'ios',
+          SupportedArchitectures: ['arm64'],
+        },
+      ],
+      CFBundlePackageType: 'XFWK',
+      XCFrameworkFormatVersion: '1.0',
+    }),
+  );
+  return xcframework;
+}
+
+describe('flavored-frameworks without the plist module', () => {
+  let tmp;
+
+  beforeEach(() => {
+    tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'ff-plist-dep-'));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmp, {recursive: true, force: true});
+  });
+
+  it('loads without requiring plist', () => {
+    expect(() => require('../flavored-frameworks')).not.toThrow();
+  });
+
+  it('parses an xcframework Info.plist via plutil', () => {
+    const {parseXcframework} = require('../flavored-frameworks');
+    const parsed = parseXcframework(makeXcframework(tmp));
+    expect(parsed.slices).toHaveLength(1);
+    expect(parsed.slices[0].libraryIdentifier).toBe('ios-arm64');
+    expect(parsed.slices[0].platform).toBe('ios');
+  });
+});

packages/react-native/scripts/spm/__tests__/flavored-frameworks-test.js

@@ -10,6 +10,28 @@
 
 'use strict';
 
+// flavored-frameworks.js shells out to `plutil` to read xcframework
+// Info.plists as JSON — plutil is macOS-only, so stand in with a portable
+// plist-parse for Linux CI. Module-level mock because the module destructures
+// `execFileSync` at require time (same pattern as the old swap-flavor-test).
+jest.mock('child_process', () => {
+  const actual = jest.requireActual('child_process');
+  return {
+    ...actual,
+    execFileSync: (cmd, args, opts) => {
+      if (cmd === 'plutil') {
+        const fsActual = require('fs');
+        const plistActual = jest.requireActual('plist');
+        const file = args[args.length - 1];
+        return Buffer.from(
+          JSON.stringify(plistActual.parse(fsActual.readFileSync(file, 'utf8'))),
+        );
+      }
+      return actual.execFileSync(cmd, args, opts);
+    },
+  };
+});
+
 const {
   PLUGIN_FRAMEWORKS_MANIFEST,
   finalizeArtifactPublication,

packages/react-native/scripts/spm/flavored-frameworks.js

@@ -14,8 +14,16 @@ const {execFileSync} = require('child_process');
 const crypto = require('crypto');
 const fs = require('fs');
 const path = require('path');
-// $FlowFixMe[untyped-import] plist does not publish Flow declarations.
-const plist = require('plist');
+
+// Info.plist parsing goes through plutil (as the pre-B1 swap script did): the
+// `plist` npm module is NOT a react-native dependency, so it only resolves
+// inside this monorepo via hoisting — requiring it breaks `spm add` in a
+// fresh consumer app with "Cannot find module 'plist'".
+function plistJson(p /*: string */) /*: $FlowFixMe */ {
+  return JSON.parse(
+    execFileSync('plutil', ['-convert', 'json', '-o', '-', p]).toString(),
+  );
+}
 
 /*:: import type {
   FlavoredFrameworkManifestEntry,
@@ -162,7 +170,7 @@ function parseXcframework(
   if (!fs.existsSync(infoPath)) {
     throw new Error(`XCFramework Info.plist missing at ${infoPath}`);
   }
-  const info = plist.parse(fs.readFileSync(infoPath, 'utf8'));
+  const info = plistJson(infoPath);
   const libraries = info.AvailableLibraries;
   if (!Array.isArray(libraries) || libraries.length === 0) {
     throw new Error(
@@ -303,9 +311,7 @@ function frameworkHeaderHashes(
 function invariantHeadersHashes(
   xcframeworkPath /*: string */,
 ) /*: Array<string> */ {
-  const info = plist.parse(
-    fs.readFileSync(path.join(xcframeworkPath, 'Info.plist'), 'utf8'),
-  );
+  const info = plistJson(path.join(xcframeworkPath, 'Info.plist'));
   if (!Array.isArray(info.AvailableLibraries)) {
     throw new Error(`XCFramework has no libraries: ${xcframeworkPath}`);
   }