chore(cli): fix fast resolver (#27686)

# Why

There was an issue where we attempted to match against the resolution
error in order to continue resolving, but the custom error didn't match
our matcher function. Now we should be able to use fast resolver in most
apps.

I've also switched the fs-extra methods over to fs which saves about
300ms in an app with 900 modules.

# Test Plan

- Tested manually.
- Tests should keep working.
- Added new tests for fragile check.

---------

Co-authored-by: Expo Bot <34669131+expo-bot@users.noreply.github.com>

packages/@expo/cli/CHANGELOG.md

@@ -16,6 +16,7 @@
 
 ### 🐛 Bug fixes
 
+- Fix issue with fast resolver. ([#27686](https://github.com/expo/expo/pull/27686) by [@EvanBacon](https://github.com/EvanBacon))
 - Fix using array syntax `(a,b)` with server output. ([#27462](https://github.com/expo/expo/pull/27462) by [@EvanBacon](https://github.com/EvanBacon))
 - Prevent `console.log` statements from colliding with Metro logs. ([#27217](https://github.com/expo/expo/pull/27217) by [@EvanBacon](https://github.com/EvanBacon))
 - Fix using dev server URL in development. ([#27213](https://github.com/expo/expo/pull/27213) by [@EvanBacon](https://github.com/EvanBacon))

packages/@expo/cli/e2e/__tests__/export.test.ts

@@ -58,7 +58,7 @@ describe('server', () => {
         env: {
           NODE_ENV: 'production',
           TEST_BABEL_PRESET_EXPO_MODULE_ID: require.resolve('babel-preset-expo'),
-          EXPO_USE_FAST_RESOLVER: 'false',
+          EXPO_USE_FAST_RESOLVER: 'true',
         },
       });
 
@@ -201,7 +201,7 @@ describe('server', () => {
           env: {
             NODE_ENV: 'production',
             TEST_BABEL_PRESET_EXPO_MODULE_ID: require.resolve('babel-preset-expo'),
-            EXPO_USE_FAST_RESOLVER: 'false',
+            EXPO_USE_FAST_RESOLVER: 'true',
           },
         }
       );

packages/@expo/cli/src/export/saveAssets.ts

@@ -31,10 +31,10 @@ export type ExportAssetDescriptor = {
 export type ExportAssetMap = Map<string, ExportAssetDescriptor>;
 
 export async function persistMetroFilesAsync(files: ExportAssetMap, outputDir: string) {
-  fs.mkdirSync(path.join(outputDir), { recursive: true });
   if (!files.size) {
     return;
   }
+  fs.mkdirSync(path.join(outputDir), { recursive: true });
 
   // Test fixtures:
   // Log.log(

packages/@expo/cli/src/start/server/getStaticRenderFunctions.ts

@@ -37,14 +37,19 @@ const debug = require('debug')('expo:start:server:node-renderer') as typeof cons
 const cachedSourceMaps: Map<string, { url: string; map: string }> = new Map();
 
 // Support unhandled rejections
-require('source-map-support').install({
-  retrieveSourceMap(source: string) {
-    if (cachedSourceMaps.has(source)) {
-      return cachedSourceMaps.get(source);
-    }
-    return null;
-  },
-});
+// Detect if running in Bun
+
+// @ts-expect-error: This is a global variable that is set by Bun.
+if (!process.isBun) {
+  require('source-map-support').install({
+    retrieveSourceMap(source: string) {
+      if (cachedSourceMaps.has(source)) {
+        return cachedSourceMaps.get(source);
+      }
+      return null;
+    },
+  });
+}
 
 function wrapBundle(str: string) {
   // Skip the metro runtime so debugging is a bit easier.

packages/@expo/cli/src/start/server/metro/__tests__/createExpoMetroResolver.test.ts

@@ -3,7 +3,8 @@ import assert from 'assert';
 import fs from 'fs';
 import path from 'path';
 
-import { createFastResolver } from '../createExpoMetroResolver';
+import { createFastResolver, FailedToResolvePathError } from '../createExpoMetroResolver';
+import { isFailedToResolvePathError } from '../metroErrors';
 
 type SupportedContext = Parameters<ReturnType<typeof createFastResolver>>[0];
 
@@ -128,6 +129,13 @@ function resolveTo(
       : null;
 }
 
+describe(isFailedToResolvePathError, () => {
+  it(`matches custom error`, () => {
+    const error = new FailedToResolvePathError('message');
+    expect(isFailedToResolvePathError(error)).toBe(true);
+  });
+});
+
 describe(createFastResolver, () => {
   describe('node built-ins', () => {
     it('shims node built-ins on non-server platforms', () => {

packages/@expo/cli/src/start/server/metro/createExpoMetroResolver.ts

@@ -13,10 +13,16 @@ import { isNodeExternal } from './externals';
 import { formatFileCandidates } from './formatFileCandidates';
 import { isServerEnvironment } from '../middleware/metroOptions';
 
-class FailedToResolvePathError extends Error {}
+export class FailedToResolvePathError extends Error {
+  // Added to ensure the error is matched by our tooling.
+  // TODO: Test that this matches `isFailedToResolvePathError`
+  candidates = {};
+}
 
 class ShimModuleError extends Error {}
 
+const debug = require('debug')('expo:metro:resolve') as typeof console.log;
+
 const realpathFS =
   process.platform !== 'win32' && fs.realpathSync && typeof fs.realpathSync.native === 'function'
     ? fs.realpathSync.native
@@ -40,6 +46,7 @@ export function createFastResolver({
   preserveSymlinks: boolean;
   blockList: RegExp[];
 }) {
+  debug('Creating with settings:', { preserveSymlinks, blockList });
   const cachedExtensions: Map<string, readonly string[]> = new Map();
 
   function getAdjustedExtensions({
@@ -110,17 +117,16 @@ export function createFastResolver({
 
     let fp: string;
 
+    const conditions = context.unstable_enablePackageExports
+      ? [
+          ...new Set([
+            'default',
+            ...context.unstable_conditionNames,
+            ...(platform != null ? context.unstable_conditionsByPlatform[platform] ?? [] : []),
+          ]),
+        ]
+      : [];
     try {
-      const conditions = context.unstable_enablePackageExports
-        ? [
-            ...new Set([
-              'default',
-              ...context.unstable_conditionNames,
-              ...(platform != null ? context.unstable_conditionsByPlatform[platform] ?? [] : []),
-            ]),
-          ]
-        : [];
-
       fp = jestResolver(moduleName, {
         blockList,
         enablePackageExports: context.unstable_enablePackageExports,
@@ -129,8 +135,18 @@ export function createFastResolver({
         extensions,
         conditions,
         realpathSync(file: string): string {
-          // @ts-expect-error: Missing on type.
-          const metroRealPath = context.unstable_getRealPath?.(file);
+          let metroRealPath: string | null = null;
+
+          try {
+            // @ts-expect-error: Missing on type.
+            metroRealPath = context.unstable_getRealPath?.(file);
+          } catch (error: any) {
+            // If invariant
+            if (error.message !== 'Unexpectedly escaped traversal') {
+              throw error;
+            }
+          }
+
           if (metroRealPath == null && preserveSymlinks) {
             return realpathSync(file);
           }
@@ -156,13 +172,7 @@ export function createFastResolver({
         // the app doesn't finish without it.
         preserveSymlinks,
         readPackageSync(readFileSync, pkgFile) {
-          return (
-            context.getPackage(pkgFile) ??
-            JSON.parse(
-              // @ts-expect-error
-              readFileSync(pkgfile)
-            )
-          );
+          return context.getPackage(pkgFile) ?? JSON.parse(fs.readFileSync(pkgFile, 'utf8'));
         },
         includeCoreModules: isServer,
 
@@ -206,6 +216,8 @@ export function createFastResolver({
           };
         }
 
+        debug({ moduleName, platform, conditions, isServer, preserveSymlinks }, context);
+
         throw new FailedToResolvePathError(
           'The module could not be resolved because no file or module matched the pattern:\n' +
             `  ${formatFileCandidates(

packages/@expo/cli/src/start/server/metro/createJResolver.ts

@@ -10,6 +10,7 @@
  */
 import type { JSONObject as PackageJSON } from '@expo/json-file';
 import assert from 'assert';
+import fs from 'fs';
 import { dirname, isAbsolute, resolve as pathResolve } from 'path';
 import { sync as resolveSync, SyncOpts as UpstreamResolveOptions } from 'resolve';
 import * as resolve from 'resolve.exports';
@@ -83,7 +84,10 @@ type ResolverOptions = {
   | 'includeCoreModules'
 >;
 
-type UpstreamResolveOptionsWithConditions = UpstreamResolveOptions & ResolverOptions;
+type UpstreamResolveOptionsWithConditions = UpstreamResolveOptions &
+  ResolverOptions & {
+    pathExists: (file: string) => boolean;
+  };
 
 const defaultResolver = (
   path: string,
@@ -109,6 +113,17 @@ const defaultResolver = (
       }
       return fileExistsSync(file);
     },
+    pathExists(file) {
+      if (blockList.some((regex) => regex.test(file))) {
+        return false;
+      }
+      try {
+        fs.accessSync(path, fs.constants.F_OK);
+        return true; // File exists
+      } catch {
+        return false; // File doesn't exist
+      }
+    },
     preserveSymlinks: options.preserveSymlinks,
     defaultResolver,
   };
@@ -138,61 +153,34 @@ function getPathInModule(path: string, options: UpstreamResolveOptionsWithCondit
 
   let moduleName = segments.shift();
 
-  if (moduleName) {
-    if (moduleName.startsWith('@')) {
-      moduleName = `${moduleName}/${segments.shift()}`;
-    }
-
-    // Disable package exports for babel/runtime for https://github.com/facebook/metro/issues/984/
-    if (moduleName === '@babel/runtime') {
-      return path;
-    }
-
-    // self-reference
-    const closestPackageJson = findClosestPackageJson(options.basedir, options);
-    if (closestPackageJson) {
-      const pkg = options.readPackageSync!(options.readFileSync!, closestPackageJson);
-      assert(pkg, 'package.json should be read by `readPackageSync`');
-
-      if (pkg.name === moduleName) {
-        const resolved = resolve.exports(
-          pkg,
-          (segments.join('/') || '.') as resolve.Exports.Entry,
-          createResolveOptions(options.conditions)
-        );
-
-        if (resolved) {
-          return pathResolve(dirname(closestPackageJson), resolved[0]);
-        }
-
-        if (pkg.exports) {
-          throw new Error(
-            "`exports` exists, but no results - this is a bug in Expo CLI's Metro resolver. Please report an issue"
-          );
-        }
-      }
-    }
+  if (!moduleName) {
+    return path;
+  }
 
-    let packageJsonPath = '';
+  if (moduleName.startsWith('@')) {
+    moduleName = `${moduleName}/${segments.shift()}`;
+  }
 
-    try {
-      packageJsonPath = resolveSync(`${moduleName}/package.json`, options);
-    } catch {
-      // ignore if package.json cannot be found
-    }
+  // Disable package exports for babel/runtime for https://github.com/facebook/metro/issues/984/
+  if (moduleName === '@babel/runtime') {
+    return path;
+  }
 
-    if (packageJsonPath && options.isFile!(packageJsonPath)) {
-      const pkg = options.readPackageSync!(options.readFileSync!, packageJsonPath);
-      assert(pkg, 'package.json should be read by `readPackageSync`');
+  // self-reference
+  const closestPackageJson = findClosestPackageJson(options.basedir, options);
+  if (closestPackageJson) {
+    const pkg = options.readPackageSync!(options.readFileSync!, closestPackageJson);
+    assert(pkg, 'package.json should be read by `readPackageSync`');
 
+    if (pkg.name === moduleName) {
       const resolved = resolve.exports(
         pkg,
         (segments.join('/') || '.') as resolve.Exports.Entry,
         createResolveOptions(options.conditions)
       );
 
       if (resolved) {
-        return pathResolve(dirname(packageJsonPath), resolved[0]);
+        return pathResolve(dirname(closestPackageJson), resolved[0]);
       }
 
       if (pkg.exports) {
@@ -203,6 +191,37 @@ function getPathInModule(path: string, options: UpstreamResolveOptionsWithCondit
     }
   }
 
+  let packageJsonPath = '';
+
+  try {
+    packageJsonPath = resolveSync(`${moduleName}/package.json`, options);
+  } catch {
+    // ignore if package.json cannot be found
+  }
+
+  if (!packageJsonPath) {
+    return path;
+  }
+
+  const pkg = options.readPackageSync!(options.readFileSync!, packageJsonPath);
+  assert(pkg, 'package.json should be read by `readPackageSync`');
+
+  const resolved = resolve.exports(
+    pkg,
+    (segments.join('/') || '.') as resolve.Exports.Entry,
+    createResolveOptions(options.conditions)
+  );
+
+  if (resolved) {
+    return pathResolve(dirname(packageJsonPath), resolved[0]);
+  }
+
+  if (pkg.exports) {
+    throw new Error(
+      "`exports` exists, but no results - this is a bug in Expo CLI's Metro resolver. Please report an issue"
+    );
+  }
+
   return path;
 }
 
@@ -220,7 +239,7 @@ const shouldIgnoreRequestForExports = (path: string) => path.startsWith('.') ||
 // https://github.com/lukeed/escalade/blob/2477005062cdbd8407afc90d3f48f4930354252b/src/sync.js
 function findClosestPackageJson(
   start: string,
-  options: UpstreamResolveOptions
+  options: UpstreamResolveOptionsWithConditions
 ): string | undefined {
   let dir = pathResolve('.', start);
   if (!options.isDirectory!(dir)) {
@@ -229,7 +248,7 @@ function findClosestPackageJson(
 
   while (true) {
     const pkgJsonFile = pathResolve(dir, './package.json');
-    const hasPackageJson = options.isFile!(pkgJsonFile);
+    const hasPackageJson = options.pathExists!(pkgJsonFile);
 
     if (hasPackageJson) {
       return pkgJsonFile;