Unable to resolve module @react-native-harness/bridge/client

[manud99]

Describe the bug

I tried to run React-Native-Harness for my Expo app on a real Android phone. I managed to start the Metro server but the app crashed because one endpoint returned the following error.

Endpoint: http://localhost:8081/.expo/.virtual-metro-entry.bundle?platform=android&dev=true&lazy=true&minify=false&app=com.example&modulesOnly=false&runModule=true&excludeSource=true&sourcePaths=url-server

Unable to resolve module @react-native-harness/bridge/client from /Users/manuel/code/redmesh-app/node_modules/@react-native-harness/runtime/dist/client/factory.js: @react-native-harness/bridge/client could not be found within the project or in these directories:
  node_modules/@react-native-harness/runtime/node_modules
  node_modules

  1  | import { getBridgeClient } from '@react-native-harness/bridge/client';
  | ^
  2 | import { store } from '../ui/state.js';
  3 | import { getTestRunner } from '../runner/index.js';
  4 | import { getTestCollector } from '../collector/index.js';

I solved the issue locally by creating the file node_modules/@react-native-harness/bridge/client.js with the following contents:

export * from './dist/client.js';
export { default } from './dist/client.js';

I suspect the problem is that getBridgeClient is not exported from @react-native-harness/bridge/client's index.ts but is imported in @react-native-harness/runtime/src/client/factory.ts. Maybe adding this second line to @react-native-harness/bridge/src/index.ts helps:

export * from './shared.js';
export * from './client.js';

System Info

System:
  OS: macOS 15.6.1
  CPU: (10) arm64 Apple M4
  Memory: 147.55 MB / 16.00 GB
  Shell:
    version: "5.9"
    path: /bin/zsh
Binaries:
  Node:
    version: 22.19.0
    path: /Users/manuel/.nvm/versions/node/v22.19.0/bin/node
  Yarn: Not Found
  npm:
    version: 10.9.3
    path: /Users/manuel/.nvm/versions/node/v22.19.0/bin/npm
  Watchman: Not Found
Managers:
  CocoaPods:
    version: 1.16.2
    path: /opt/homebrew/lib/ruby/gems/3.4.0/bin/pod
SDKs:
  iOS SDK:
    Platforms:
      - DriverKit 24.5
      - iOS 18.5
      - macOS 15.5
      - tvOS 18.5
      - visionOS 2.5
      - watchOS 11.5
  Android SDK: Not Found
IDEs:
  Android Studio: 2025.1 AI-251.27812.49.2514.14217341
  Xcode:
    version: 16.4/16F6
    path: /usr/bin/xcodebuild
Languages:
  Java:
    version: 17.0.16
    path: /usr/bin/javac
  Ruby:
    version: 3.4.5
    path: /opt/homebrew/opt/ruby/bin/ruby
npmPackages:
  "@react-native-community/cli":
    installed: 20.0.2
    wanted: latest
  react:
    installed: 18.3.1
    wanted: 18.3.1
  react-native:
    installed: 0.76.9
    wanted: 0.76.9
  react-native-macos: Not Found
npmGlobalPackages:
  "*react-native*": Not Found
Android:
  hermesEnabled: true
  newArchEnabled: true
iOS:
  hermesEnabled: true
  newArchEnabled: true

React Native Harness Version

1.0.0-alpha.19

Reproduction

Steps to reproduce

[V3RON]

Hey @manud99!

The problem is that your React Native version is quite old, and if I remember correctly, it ignores the exports property in package.json files, which is used by Harness. You can opt in to support for this by adding resolver.unstable_enablePackageExports: true to your Metro config. Let me know if this works for you.

[manud99]

I tested it and it in fact works. It also solves my bundling error that I got when executing tests. Therefore, thank you very much for your suggestion.