react
diff --git a/‎packages/jest-preset/jest-preset.js‎
Lines changed: 59 additions & 2 deletions b/‎packages/jest-preset/jest-preset.js‎
Lines changed: 59 additions & 2 deletions
diff --git a/‎packages/jest-preset/jest/__tests__/preset-react-native-dep-test.js‎
Lines changed: 145 additions & 0 deletions b/‎packages/jest-preset/jest/__tests__/preset-react-native-dep-test.js‎
Lines changed: 145 additions & 0 deletions
@@ -12,6 +12,60 @@
 
 const path = require('node:path');
 
+// Package directories whose sources must be transformed rather than ignored.
+const RN = '(jest-)?react-native';
+const RN_SCOPE = '@react-native(-community)?';
+
+// Yarn pnpm-mode names every store entry `<flat-name>-<protocol>-<hash>`,
+// where `<protocol>` is how the package was resolved. `npm` is the only one
+// that also carries the version. A package declaring peer dependencies
+// resolves as `virtual` regardless of where it came from. Observed under Yarn
+// 4.18: `react-native-npm-1000.0.0-30881e83e6`, `react-native-file-d30a842e27`,
+// `is-odd-patch-cfbe751c88`. Listing the protocols explicitly rather than
+// accepting any word keeps `react-native-reanimated-npm-1.0.0-<hash>` from
+// matching with `reanimated` in the protocol position.
+const STORE_PROTOCOL = 'virtual|patch|file|portal|link|exec|workspace';
+const STORE_SUFFIX = `(-npm-[^\\/]+|-(?:${STORE_PROTOCOL})-[0-9a-f]+)`;
+
+// Locations, one per install layout, where a react-native package directory
+// may legitimately sit. Each is an alternative of a single negative lookahead
+// applied after `node_modules/`, so anything not listed here stays ignored.
+//
+// The prefixes are anchored instead of allowing arbitrary leading segments.
+// Without that anchoring, a scoped third-party package whose unscoped name is
+// exactly `react-native` (`@sentry/react-native`, `@notifee/react-native`) or
+// a directory literally named `react-native` nested inside an unrelated
+// package would match and be transformed.
+const TRANSFORMED_PACKAGE_LAYOUTS = [
+  // Classic `node_modules/react-native/...`, and pnpm's
+  // `node_modules/.pnpm/<id>/node_modules/react-native/...` — the same shape
+  // behind an optional store prefix. The trailing `[\/]` is required: without
+  // it the package name would also match a longer one it merely prefixes, so
+  // `react-native-reanimated` would be transformed. Yarn's `-virtual-<hash>`
+  // entries are deliberately not accepted here — they only ever appear under
+  // `.store/`, which the next alternative handles.
+  `(\\.pnpm/([^\\/]+/)?node_modules/)?(${RN}|${RN_SCOPE})[\\/]`,
+
+  // Yarn pnpm-mode's content store:
+  // `node_modules/.store/<flat>-<protocol>-<hash>/package/...`, where `<flat>`
+  // is the package name with its scope slash flattened to a dash.
+  //
+  // The scope segment `(?:-[^-\/]+)*` must keep `-` out of its inner class.
+  // Allowing it there lets the segment consume dashes itself, which gives a
+  // dash-separated name exponentially many possible partitions and makes any
+  // near-miss path under `.store/@react-native-...` backtrack catastrophically.
+  // Jest tests this pattern against every candidate file path, so a single
+  // such path would hang the run.
+  //
+  // Flattening erases the scope boundary here, so a third-party
+  // `@react-native-<scope>/*` package (e.g.
+  // `@react-native-async-storage/async-storage`) is indistinguishable from a
+  // genuine `@react-native/*` one and is transformed too. Transforming is the
+  // safe direction — missing one would ship untransformed sources — and the
+  // cost is performance only, confined to Yarn pnpm-mode.
+  `\\.store/(${RN}${STORE_SUFFIX}|${RN_SCOPE}(?:-[^-\\/]+)*${STORE_SUFFIX})/package/`,
+];
+
 module.exports = {
   haste: {
     defaultPlatform: 'ios',
@@ -29,12 +83,15 @@ module.exports = {
   },
   resolver: require.resolve('./jest/resolver.js'),
   transform: {
-    '^.+\\.(js|ts|tsx)$': '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)?)/)',
+    `node_modules/(?!${TRANSFORMED_PACKAGE_LAYOUTS.join('|')})`,
   ],
   setupFiles: [require.resolve('./jest/setup.js')],
   testEnvironment: require.resolve('./jest/react-native-env.js'),
 
@@ -0,0 +1,145 @@
+/**
+ * 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 = ${JSON.stringify(isoPreset)};`,
+      `console.log('CHILD_NODE_PATH:' + (process.env.NODE_PATH ?? '(unset)'));`,
+      `console.log('LOOKUP:' + JSON.stringify(require('module')._nodeModulePaths(isoDir)));`,
+      `let probe;`,
+      `try { probe = 'RESOLVED:' + require.resolve('react-native', {paths: [isoDir]}); } catch (e) { probe = 'UNREACHABLE:' + e.code + ':' + String(e.message).split('\\n')[0]; }`,
+      `console.log('PROBE:' + probe);`,
+      `const preset = require(isoPreset);`,
+      `console.log('PRESET_TRANSFORM:' + preset.transform['^.+\\\\.(js|ts|tsx)$']);`,
+      `console.log('PRESET_LOADED');`,
+    ].join('\n');
+    const child = spawnSync(process.execPath, ['-e', probeScript], {
+      cwd: consumerDir,
+      encoding: 'utf8',
+      env: childEnv,
+    });
+    const stdout = String(child.stdout ?? '');
+    const childOutput =
+      `Child output:\n${stdout}\n` +
+      `Child stderr:\n${String(child.stderr ?? '')}`;
+    if (child.status !== 0) {
+      throw new Error(
+        `Isolated preset failed to load (${RN_ISSUE}).\n${childOutput}`,
+      );
+    }
+
+    // A zero exit code alone would also be produced by a child that never
+    // reached the preset, so assert on what it reported. `react-native` must
+    // resolve from the isolated copy's own scope: that only happens because
+    // the manifest declares it, which is the regression this test guards.
+    const read = (label: string): string => {
+      const match = stdout.match(new RegExp(`^${label}:(.*)$`, 'm'));
+      if (match == null) {
+        throw new Error(
+          `Child never printed ${label} (${RN_ISSUE}).\n${childOutput}`,
+        );
+      }
+      return match[1];
+    };
+
+    expect(read('PROBE')).toBe(
+      `RESOLVED:${presetRequire.resolve('react-native')}`,
+    );
+    // `jest-preset.js` calls `require.resolve('babel-jest')` from its own
+    // scope; a bare specifier would only have resolved by hoisting.
+    expect(read('PRESET_TRANSFORM')).toBe(presetRequire.resolve('babel-jest'));
+    expect(stdout).toContain('PRESET_LOADED');
+  } finally {
+    fs.rmSync(scratch, {recursive: true, force: true});
+  }
+});