Fix @react-native/jest-preset failing under pnpm and Yarn pnpm-mode

packages/jest-preset/jest-preset.js

@@ -29,12 +29,24 @@ module.exports = {
   },
   resolver: require.resolve('./jest/resolver.js'),
   transform: {
-    '^.+\\.(js|ts|tsx)$': 'babel-jest',
+    // Resolve from the preset's own scope so strict-isolation installs
+    // (pnpm / Yarn pnpm-mode) find the transformer without relying on
+    // hoisting or a consumer devDependency.
+    '^.+\\.(js|ts|tsx)$': require.resolve('babel-jest'),
     '^.+\\.(bmp|gif|jpg|jpeg|mp4|png|psd|svg|webp)$':
       require.resolve('./jest/assetFileTransformer.js'),
   },
   transformIgnorePatterns: [
-    'node_modules/(?!((jest-)?react-native|@react-native(-community)?)/)',
+    // Match react-native packages at any nesting depth so pnpm
+    // (node_modules/.pnpm/<hash>/node_modules/...) and Yarn pnpm-mode
+    // (node_modules/.store/<virtual>/package/...) layouts still transform
+    // preset and react-native sources instead of ignoring them as opaque
+    // node_modules. A trailing `-virtual-<hexhash>` synthetic suffix (Yarn,
+    // e.g. @react-native-jest-preset-virtual-2eb6229c53) is allowed; real
+    // `-suffix` packages such as react-native-reanimated, react-native-svg,
+    // @react-native-async-storage/async-storage, or
+    // react-native-virtual-* stay ignored, exactly as before.
+    'node_modules/(?!([^\\/]*[\\/])*((jest-)?react-native|@react-native(-community)?)(([^\\/]*-virtual-[0-9a-f]+)?[\\/]|$))',
   ],
   setupFiles: [require.resolve('./jest/setup.js')],
   testEnvironment: require.resolve('./jest/react-native-env.js'),

packages/jest-preset/jest/__tests__/preset-react-native-dep-test.js

@@ -0,0 +1,121 @@
+/**
+ * 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
+ * @format
+ */
+
+import {spawnSync} from 'node:child_process';
+import fs from 'node:fs';
+import {createRequire} from 'node:module';
+import os from 'node:os';
+import path from 'node:path';
+
+const RN_ISSUE = 'https://github.com/react/react-native/issues/56641';
+
+test(`isolated preset loads when the consumer provides react-native (${RN_ISSUE})`, () => {
+  const presetDir = path.resolve(__dirname, '..', '..');
+  const presetRequire = createRequire(path.join(presetDir, 'package.json'));
+  const scratch = fs.mkdtempSync(
+    path.join(os.tmpdir(), 'rn-jest-preset-56641-'),
+  );
+  try {
+    const isoDir = path.join(scratch, 'isolated-preset');
+    const consumerDir = path.join(scratch, 'consumer');
+    fs.mkdirSync(consumerDir, {recursive: true});
+
+    // Mimic pnpm/Yarn pnpm-mode isolation: copy the preset so bare
+    // specifiers resolve from the copy, which sees only what a package
+    // manager would install there. Exclude node_modules: an open-source
+    // Yarn install can create a per-package one, and if it contained
+    // react-native or babel-jest the copy would inherit it and the test
+    // would pass when it should fail.
+    fs.cpSync(presetDir, isoDir, {
+      recursive: true,
+      filter: src => !src.split(path.sep).includes('node_modules'),
+    });
+
+    // Mirror a package-manager install of declared dependencies into the
+    // isolated copy. This intentionally provides nothing beyond what the
+    // manifest declares: every dependency, peer, and optional peer is
+    // linked from the repo, so `require.resolve` from the copy sees exactly
+    // the declared surface (notably `babel-jest`, needed by `jest-preset.js`
+    // itself, as well as `react-native` when declared).
+    const pkg = JSON.parse(
+      fs.readFileSync(path.join(presetDir, 'package.json'), 'utf8'),
+    );
+    const declared = new Set([
+      ...Object.keys(pkg.dependencies ?? {}),
+      ...Object.keys(pkg.peerDependencies ?? {}),
+      ...Object.keys(pkg.optionalDependencies ?? {}),
+    ]);
+    for (const name of declared) {
+      const target = path.join(isoDir, 'node_modules', name);
+      fs.mkdirSync(path.dirname(target), {recursive: true});
+      const depDir = path.dirname(
+        presetRequire.resolve(`${name}/package.json`),
+      );
+      fs.symlinkSync(depDir, target, 'dir');
+    }
+
+    // A consuming project always has its own copy.
+    const consumerRnDir = path.dirname(
+      presetRequire.resolve('react-native/package.json'),
+    );
+    const consumerTarget = path.join(
+      consumerDir,
+      'node_modules',
+      'react-native',
+    );
+    fs.mkdirSync(path.dirname(consumerTarget), {recursive: true});
+    fs.symlinkSync(consumerRnDir, consumerTarget, 'dir');
+
+    // Strip resolution-affecting env so the child is genuinely isolated:
+    // inherited lookup paths can otherwise make the copy resolve more
+    // than the directory layout alone provides.
+    const childEnv: {[string]: string} = {};
+    for (const key of Object.keys(process.env)) {
+      if (key === 'NODE_PATH' || key === 'NODE_OPTIONS') {
+        continue;
+      }
+      const value = process.env[key];
+      if (value != null) {
+        childEnv[key] = value;
+      }
+    }
+
+    // The child probes what the isolated copy can actually resolve, prints
+    // the outcome, then loads the preset. Both probes use the isolated
+    // copy as the resolution scope.
+    const isoPreset = path.join(isoDir, 'jest-preset.js');
+    const probeScript = [
+      `const isoDir = ${JSON.stringify(isoDir)};`,
+      `const isoPreset = ${JSON.stringify(isoPreset)};`,
+      `console.log('CHILD_NODE_PATH:' + (process.env.NODE_PATH ?? '(unset)'));`,
+      `console.log('LOOKUP:' + JSON.stringify(require('module')._nodeModulePaths(isoDir)));`,
+      `let probe;`,
+      `try { probe = 'RESOLVED:' + require.resolve('react-native', {paths: [isoDir]}); } catch (e) { probe = 'UNREACHABLE:' + e.code + ':' + String(e.message).split('\\n')[0]; }`,
+      `console.log('PROBE:' + probe);`,
+      `require(isoPreset);`,
+      `console.log('PRESET_LOADED');`,
+    ].join('\n');
+    const child = spawnSync(process.execPath, ['-e', probeScript], {
+      cwd: consumerDir,
+      encoding: 'utf8',
+      env: childEnv,
+    });
+    const stdout = String(child.stdout ?? '');
+    if (child.status !== 0) {
+      throw new Error(
+        `Isolated preset failed to load (${RN_ISSUE}).\n` +
+          `Child output:\n${stdout}\n` +
+          `Child stderr:\n${String(child.stderr ?? '')}`,
+      );
+    }
+  } finally {
+    fs.rmSync(scratch, {recursive: true, force: true});
+  }
+});

packages/jest-preset/jest/__tests__/preset-transform-isolation-test.js

@@ -0,0 +1,87 @@
+/**
+ * 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.
+ *
+ * @format
+ * @noflow
+ */
+
+import fs from 'node:fs';
+import {createRequire} from 'node:module';
+import path from 'node:path';
+
+const RN_ISSUE = 'https://github.com/react/react-native/issues/56641';
+
+const presetDir = path.resolve(__dirname, '..', '..');
+const presetRequire = createRequire(path.join(presetDir, 'package.json'));
+
+describe(`preset transform survives strict isolation (${RN_ISSUE})`, () => {
+  const preset = require('../../jest-preset');
+
+  test('JS transformer resolves from the preset scope', () => {
+    const jsTransform = preset.transform['^.+\\.(js|ts|tsx)$'];
+    // A bare 'babel-jest' specifier only resolves by hoisting or a consumer
+    // devDependency. Under pnpm / Yarn pnpm-mode the consumer scope does not
+    // see the preset's dependencies, so the transformer must resolve from
+    // the preset's own scope.
+    expect(jsTransform).toBe(presetRequire.resolve('babel-jest'));
+    expect(fs.existsSync(jsTransform)).toBe(true);
+  });
+
+  test('transformIgnorePatterns covers pnpm/Yarn layouts without widening', () => {
+    const re = new RegExp(preset.transformIgnorePatterns[0]);
+    // [path, shouldBeIgnored]. pnpm (.pnpm/<hash>/node_modules) and Yarn
+    // pnpm-mode (.store/<virtual>/package) layouts must transform preset and
+    // react-native sources; real `-suffix` packages must stay ignored exactly
+    // as before.
+    const cases: Array<[string, boolean]> = [
+      ['/app/node_modules/@react-native/jest-preset/jest/setup.js', false],
+      ['/app/node_modules/react-native/Libraries/AppState/AppState.js', false],
+      ['/app/node_modules/lodash/lodash.js', true],
+      ['/app/node_modules/react-native-reanimated/lib/index.js', true],
+      ['/app/node_modules/react-native-svg/lib/index.js', true],
+      [
+        '/app/node_modules/@react-native-async-storage/async-storage/lib/index.js',
+        true,
+      ],
+      ['/app/node_modules/react-native-virtualized-view/lib/index.js', true],
+      ['/app/node_modules/react-native-virtual-joystick/lib/index.js', true],
+      ['/app/node_modules/react-native-virtual-keyboard/lib/index.js', true],
+      ['/app/node_modules/react-native-virtual-list/lib/index.js', true],
+      [
+        '/tmp/x/node_modules/.pnpm/@react-native+jest-preset@file+preset_abc/node_modules/@react-native/jest-preset/jest/setup.js',
+        false,
+      ],
+      [
+        '/tmp/x/node_modules/.pnpm/react-native@1000.0.0/node_modules/react-native/Libraries/AppState/AppState.js',
+        false,
+      ],
+      [
+        '/tmp/x/node_modules/.pnpm/lodash@4.17.21/node_modules/lodash/lodash.js',
+        true,
+      ],
+      [
+        '/tmp/x/node_modules/.pnpm/react-native-reanimated@1.0.0/node_modules/react-native-reanimated/lib/index.js',
+        true,
+      ],
+      [
+        '/tmp/x/node_modules/.pnpm/react-native-svg@1.0.0/node_modules/react-native-svg/lib/index.js',
+        true,
+      ],
+      [
+        '/tmp/x/node_modules/.pnpm/@react-native-async-storage+async-storage@1.0.0/node_modules/@react-native-async-storage/async-storage/lib/index.js',
+        true,
+      ],
+      [
+        '/tmp/x/node_modules/.store/@react-native-jest-preset-virtual-abc123/package/jest/mock.js',
+        false,
+      ],
+      ['/tmp/x/packages/app/__tests__/App.test.js', false],
+    ];
+    for (const [file, shouldIgnore] of cases) {
+      expect(re.test(file)).toBe(shouldIgnore);
+    }
+  });
+});

packages/jest-preset/package.json

@@ -28,13 +28,16 @@
     "!**/__tests__/**"
   ],
   "dependencies": {
+    "@babel/runtime": "^7.25.0",
     "@jest/create-cache-key-function": "^29.7.0",
     "@react-native/js-polyfills": "0.87.0-main",
     "babel-jest": "^29.7.0",
     "jest-environment-node": "^29.7.0",
     "regenerator-runtime": "^0.13.2"
   },
   "peerDependencies": {
-    "react": "^19.2.3"
+    "@babel/core": "^7.25.2",
+    "react": "^19.2.3",
+    "react-native": "1000.0.0"
   }
 }