[No QA] Run Jest app sources through the OXC transformer

.github/workflows/test.yml

@@ -39,11 +39,11 @@ jobs:
           # Per-shard key: each shard only instruments the ~1/8 of suites it runs, so a single
           # shared key freezes one shard's partial cache for all shards. The hash refreshes the
           # cache when dependencies or Babel config change; restore-keys warms it in between.
-          key: ${{ runner.os }}-jest-${{ matrix.chunk }}-${{ hashFiles('package-lock.json', 'patches/**', 'babel.config.js') }}
+          key: ${{ runner.os }}-jest-${{ matrix.chunk }}-${{ hashFiles('package-lock.json', 'patches/**', 'babel.config.js', 'jest.config.js', 'config/babel/oxcJestTransformer.js', 'config/babel/reactCompilerConfig.js') }}
           restore-keys: ${{ runner.os }}-jest-${{ matrix.chunk }}-
 
       - name: Jest tests
-        run: npm test -- --silent --shard=${{ fromJSON(matrix.chunk) }}/${{ strategy.job-total }} --maxWorkers=6 --coverage --coverageDirectory=coverage/shard-${{ matrix.chunk }}
+        run: npm test -- --silent --shard=${{ fromJSON(matrix.chunk) }}/${{ strategy.job-total }} --maxWorkers=4 --coverage --coverageDirectory=coverage/shard-${{ matrix.chunk }}
 
       - name: Upload coverage to Codecov (PRs - tokenless)
         if: ${{ github.event_name == 'pull_request' }}

__mocks__/react-native.ts

@@ -39,7 +39,6 @@ jest.doMock('react-native', () => {
     const reactNativeMock = Object.setPrototypeOf(
         {
             NativeModules: {
-                ...ReactNative.NativeModules,
                 BootSplash: {
                     hide: jest.fn().mockResolvedValue(undefined),
                     logoSizeRatio: 1,

config/babel/oxcJestTransformer.js

@@ -1,10 +1,15 @@
 const crypto = require('crypto');
 const fs = require('fs');
 const path = require('path');
-const esbuild = require('esbuild');
+const babel = require('@babel/core');
 const {transformSync} = require('oxc-transform-react');
 
 const babelJest = require('babel-jest');
+const BABEL_CORE_VERSION = require('@babel/core/package.json').version;
+const BLOCK_SCOPING_PLUGIN_VERSION = require('@babel/plugin-transform-block-scoping/package.json').version;
+const DYNAMIC_IMPORT_PLUGIN_VERSION = require('@babel/plugin-transform-dynamic-import/package.json').version;
+const CJS_PLUGIN_VERSION = require('@babel/plugin-transform-modules-commonjs/package.json').version;
+const JEST_HOIST_VERSION = require('babel-plugin-jest-hoist/package.json').version;
 const OXC_TRANSFORM_REACT_VERSION = require('oxc-transform-react/package.json').version;
 const BaseReactCompilerConfig = require('./reactCompilerConfig');
 
@@ -14,6 +19,7 @@ const NODE_MODULES_RE = /[/\\]node_modules[/\\]/;
 const TESTS_RE = /[/\\]tests[/\\]/;
 const JEST_SETUP_RE = /[/\\]jest[/\\]/;
 const MOCKS_RE = /[/\\]__mocks__[/\\]/;
+const JEST_HOIST_RE = /\bjest\s*\.\s*(mock|unmock|deepUnmock|disableAutomock|enableAutomock)\b/;
 
 const TRANSFORMER_SOURCE = fs.readFileSync(__filename);
 const REACT_COMPILER_CONFIG_KEY = JSON.stringify(BaseReactCompilerConfig);
@@ -24,6 +30,10 @@ const REACT_COMPILER_OPTIONS = {
     eslintSuppressionRules: [],
 };
 
+const CJS_PLUGIN_OPTIONS = {loose: true, strictMode: false};
+const CJS_PLUGINS = ['@babel/plugin-transform-block-scoping', '@babel/plugin-transform-dynamic-import', ['@babel/plugin-transform-modules-commonjs', CJS_PLUGIN_OPTIONS]];
+const CJS_AND_HOIST_PLUGINS = [...CJS_PLUGINS, 'babel-plugin-jest-hoist'];
+
 function getLang(filename) {
     const ext = path.extname(filename).slice(1);
     if (ext === 'tsx') {
@@ -39,27 +49,45 @@ function shouldUseOxc(filename) {
     return !NODE_MODULES_RE.test(filename) && !TESTS_RE.test(filename) && !JEST_SETUP_RE.test(filename) && !MOCKS_RE.test(filename);
 }
 
+function shouldRunReactCompiler(filename) {
+    return !TESTS_RE.test(filename) && !JEST_SETUP_RE.test(filename) && !MOCKS_RE.test(filename);
+}
+
+function toCommonJS(code, sourcePath, inputSourceMap) {
+    const plugins = JEST_HOIST_RE.test(code) ? CJS_AND_HOIST_PLUGINS : CJS_PLUGINS;
+    const result = babel.transformSync(code, {
+        filename: sourcePath,
+        ast: false,
+        code: true,
+        babelrc: false,
+        configFile: false,
+        compact: false,
+        sourceType: 'module',
+        sourceMaps: true,
+        inputSourceMap: inputSourceMap ?? undefined,
+        plugins,
+    });
+
+    if (!result?.code) {
+        return {code, map: inputSourceMap};
+    }
+
+    return {code: result.code, map: result.map ?? inputSourceMap};
+}
+
 function processWithOxc(sourceText, sourcePath) {
     const oxcResult = transformSync(sourcePath, sourceText, {
         lang: getLang(sourcePath),
         sourcemap: true,
         jsx: {runtime: 'automatic', development: true},
-        reactCompiler: REACT_COMPILER_OPTIONS,
+        reactCompiler: shouldRunReactCompiler(sourcePath) ? REACT_COMPILER_OPTIONS : false,
     });
 
     if (oxcResult.fatal || !oxcResult.code) {
         return null;
     }
 
-    const cjs = esbuild.transformSync(oxcResult.code, {
-        loader: 'js',
-        format: 'cjs',
-        supported: {'dynamic-import': false},
-        sourcefile: sourcePath,
-        sourcemap: true,
-    });
-
-    return {code: cjs.code, map: cjs.map};
+    return toCommonJS(oxcResult.code, sourcePath, oxcResult.map);
 }
 
 module.exports = {
@@ -76,15 +104,24 @@ module.exports = {
             .update(sourcePath)
             .update(TRANSFORMER_SOURCE)
             .update(REACT_COMPILER_CONFIG_KEY)
-            .update(esbuild.version)
+            .update(JSON.stringify(CJS_PLUGIN_OPTIONS))
+            .update(BABEL_CORE_VERSION)
+            .update(BLOCK_SCOPING_PLUGIN_VERSION)
+            .update(DYNAMIC_IMPORT_PLUGIN_VERSION)
+            .update(CJS_PLUGIN_VERSION)
+            .update(JEST_HOIST_VERSION)
             .update(OXC_TRANSFORM_REACT_VERSION)
             .digest('hex');
     },
     process(sourceText, sourcePath, transformOptions) {
         if (shouldUseOxc(sourcePath)) {
-            const result = processWithOxc(sourceText, sourcePath);
-            if (result) {
-                return result;
+            try {
+                const result = processWithOxc(sourceText, sourcePath);
+                if (result) {
+                    return result;
+                }
+            } catch {
+                // Fall through to babel-jest for syntax OXC or the CJS pass cannot parse.
             }
         }
 

jest.config.js

@@ -18,10 +18,10 @@ module.exports = {
         `<rootDir>/?(*.)+(spec|test).${testFileExtension}`,
     ],
     transform: {
-        // Reassure re-transforms ~7k files under `--max-opt=1` (V8 sparkplug only), which
-        // makes Babel ~half of each measure job. OXC + esbuild is native and stays fast
-        // without TurboFan. Test files stay on babel-jest so `jest.mock` is still hoisted.
-        '^.+\\.[jt]sx?$': isPerfTestRun ? '<rootDir>/config/babel/oxcJestTransformer.js' : 'babel-jest',
+        // App sources use OXC for TS/JSX and React Compiler, followed by a small Babel
+        // CommonJS pass. Test, setup, mock, and Flow files use babel-jest directly to avoid
+        // paying for both OXC and Babel transforms.
+        '^.+\\.[jt]sx?$': '<rootDir>/config/babel/oxcJestTransformer.js',
         '^.+\\.svg?$': 'jest-transformer-svg',
     },
     transformIgnorePatterns: [

jest/setup.ts

@@ -49,6 +49,27 @@ jest.mock('expo-task-manager', () => ({
     // Add other methods here if you use them
 }));
 
+jest.mock('expo-web-browser', () => ({
+    openAuthSessionAsync: jest.fn(() => Promise.resolve({type: 'dismiss'})),
+    maybeCompleteAuthSession: jest.fn(),
+}));
+
+// jest-expo's haste map uses defaultPlatform 'ios', so `@components/ImageSVG` resolves to
+// index.ios.tsx which imports expo-image. expo-image has no jest-expo mock, so requireNativeModule
+// throws. Stub the package so UI tests can load Icon/ImageSVG.
+jest.mock('expo-image', () => ({
+    Image: Object.assign(({source}: {source?: unknown}) => (typeof source === 'string' ? source : null), {
+        clearMemoryCache: jest.fn(() => Promise.resolve(true)),
+        prefetch: jest.fn(() => Promise.resolve(true)),
+    }),
+}));
+
+jest.mock('expo-store-review', () => ({
+    hasAction: jest.fn(() => Promise.resolve(false)),
+    isAvailableAsync: jest.fn(() => Promise.resolve(false)),
+    requestReview: jest.fn(() => Promise.resolve()),
+}));
+
 // Mock expo-location — the jest-expo preset replaces all native module methods with jest.fn(async () => {}),
 // which returns undefined instead of a proper PermissionResponse. This causes crashes when code reads .status
 // from the result of requestForegroundPermissionsAsync().

knip.json

@@ -86,7 +86,11 @@
         "shellcheck",
         "patch-package",
         "diff-so-fancy",
-        "@babel/plugin-proposal-class-properties"
+        "@babel/plugin-proposal-class-properties",
+        "@babel/plugin-transform-block-scoping",
+        "@babel/plugin-transform-dynamic-import",
+        "@babel/plugin-transform-modules-commonjs",
+        "babel-plugin-jest-hoist"
     ],
     "ignoreBinaries": ["metro-symbolicate", "mkcert", "openssl"]
 }