Add setup-module-windows command to streamline RNW community module integration

[Copilot]

This PR implements the setup-module-windows command to automate the complete workflow for adding Windows support to React Native community modules, as requested in issue #15078.

What it does

The command performs all 10 steps outlined in the issue:

1. TurboModule Spec Detection/Creation - Checks for existing spec files, creates Hello World spec if none found (instead of erroring out)
2. Package.json Updates - Adds proper codegenConfig for Windows
3. Dependency Cleanup - Removes node_modules for clean start
4. Dependency Installation - Runs yarn install
5. Dependency Upgrades - Updates RN/RNW to latest versions (optional)
6. Dependency Reinstallation - Runs yarn install again
7. Windows Library Setup - Executes init-windows --template cpp-lib
8. Code Generation - Runs codegen-windows
9. C++ Stub Generation - Creates working C++ header and implementation files
10. Build Verification - Validates the setup can be built (optional)

Key Features

• Proper naming: Command is setup-module-windows as requested
• Hello World examples: Creates functional TurboModule spec with working methods
• Reference multiply function: Kept with educational comments for new developers
• Working C++ stubs: Generated files include complete implementations that work immediately
• Comprehensive error handling: Validates environment and provides clear error messages
• Flexible options: --skip-deps, --skip-build, --logging, --no-telemetry

Generated Hello World Methods

The spec file includes these immediately functional methods:

// Hello World method - A simple greeting function to verify the module works
sayHello(name: string): Promise<string>;

// Reference multiply function - Keep this as a learning example
multiply(a: number, b: number): Promise<number>;

// Example async method with no parameters
getRandomNumber(): Promise<number>;

// Example method with boolean return
isModuleReady(): Promise<boolean>;

Each method has a complete C++ implementation that works out of the box, allowing developers to test the module immediately and learn from working examples.

Usage

yarn react-native setup-module-windows [options]

Benefits

• Zero to working module: Transforms any React Native module into a Windows-compatible module in one command
• Educational value: Includes working examples and reference implementations
• Best practices: Generated code follows RNW coding standards
• Time savings: Automates hours of manual setup work
• Error prevention: Handles common setup pitfalls automatically

This implementation addresses all feedback from the issue, providing a complete solution that gets developers from zero to a working Windows module with functional examples they can test immediately.

Fixes #15078.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• googlechromelabs.github.io
  • Triggering command: /usr/local/bin/node install.mjs (dns block)
• https://api.github.com/repos/facebook/react-native/commits/42c8dead6
  • Triggering command: /usr/local/bin/node /home/REDACTED/work/react-native-windows/react-native-windows/node_modules/jest/bin/jest.js --config /home/REDACTED/work/react-native-windows/react-native-windows/packages/@rnw-scripts/jest-e2e-config/jest.e2e.config.js --runInBand (http block)
• https://api.github.com/repos/facebook/react-native/commits/56cf99a96
  • Triggering command: /usr/local/bin/node /home/REDACTED/work/react-native-windows/react-native-windows/node_modules/jest/bin/jest.js --config /home/REDACTED/work/react-native-windows/react-native-windows/packages/@rnw-scripts/jest-e2e-config/jest.e2e.config.js --runInBand (http block)
• https://storage.googleapis.com/chrome-for-testing-public/130.0.6723.116/linux64/chrome-linux64.zip
  • Triggering command: /usr/local/bin/node install.mjs (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

💬 Share your feedback on Copilot coding agent for the chance to win a $200 gift card! Click here to start the survey.

Microsoft Reviewers: Open in CodeFlow

[anupriya13]

@copilot add a flag to support cpp-app too .. default should be cpp-lib