feat: Google Signin

[IronTony]

Related Issue(s)

N/A

Motivation

The @forward-software/react-auth library currently lacks built-in support for Google Sign-In. Users who want Google authentication need to manually wire up their own adapter, handling platform differences between web and React Native themselves. This PR adds an official Google Sign-In package that works out of the box on both platforms.

Description of Changes

• Added a new @forward-software/react-auth-google package under packages/google-signin/ that provides a Google Sign-In AuthClient adapter for both web and React Native
• Implemented native modules for iOS (Swift) and Android (Kotlin) to handle Google Sign-In via platform-specific APIs (Google Identity Services on web, CocoaPods on iOS, Android Credential Manager on Android)
• Added a GoogleSignInButton component with platform-specific implementations for easy drop-in integration
• Included support for nonce parameter to protect against replay attacks, configurable OAuth scopes, and server auth code retrieval
• Added unit tests for GoogleAuthClient on both web and native platforms
• Updated pnpm-workspace.yaml and pnpm-lock.yaml to include the new package

How to Test

1. CI Checks: Verify that all automated tests (Vitest) and build steps pass successfully on this PR.
2. Local Verification (Optional):
   -- Run pnpm install (or equivalent).
   -- Run the development server (pnpm dev or equivalent) for the library or examples to ensure Vite starts correctly.
   -- Run a build (pnpm build or equivalent) to ensure it completes successfully.
3. Package-specific tests: Run pnpm --filter @forward-software/react-auth-google test to execute the Google Sign-In unit tests.

Checklist

• My code follows the project's style guidelines
• I have added or updated tests to cover the changes
• I have updated relevant documentation
• All tests are passing locally
• CI checks are passing
• I have reviewed my own code and lock file changes
• I have checked for any potential security implications
• I have verified the changes work as expected

Notes for Reviewers

• This is a new package, so there are no breaking changes to existing functionality.
• The package uses platform-specific entry points (index.ts for web, index.native.ts for React Native) resolved automatically by the bundler.
• expo-modules-core and react-native are optional peer dependencies, allowing the package to be used in web-only projects without pulling in native dependencies.
• The web implementation loads the Google Identity Services script on-demand with a 10-second timeout.

[Copilot]

Pull request overview

This PR introduces a new @forward-software/react-auth-google package to provide an official Google Sign-In AuthClient adapter and drop-in sign-in button for both Web (Google Identity Services) and React Native (Expo Modules + native iOS/Android implementations).

Changes:

• Added a new packages/google-signin package with web + native GoogleAuthClient, GoogleSignInButton, and shared types.
• Added Expo native modules for iOS (Swift + CocoaPods) and Android (Kotlin + Credential Manager) to perform Google Sign-In.
• Added Vitest unit tests and updated the pnpm workspace to include packages/*.

Reviewed changes

Copilot reviewed 25 out of 26 changed files in this pull request and generated 9 comments.

Show a summary per file

File	Description
pnpm-workspace.yaml	Expands workspace globs to include packages/* so the new package is picked up.
packages/google-signin/vitest.config.ts	Adds Vitest config for the new package.
packages/google-signin/tsconfig.json	Adds TS build configuration for the new package.
packages/google-signin/test/test-utils.ts	Adds mock storage + JWT helpers for tests.
packages/google-signin/test/GoogleAuthClient.web.spec.ts	Adds unit tests for web GoogleAuthClient.
packages/google-signin/test/GoogleAuthClient.native.spec.ts	Adds unit tests for native GoogleAuthClient with mocked Expo native module.
packages/google-signin/src/types.ts	Defines cross-platform public types/configuration.
packages/google-signin/src/web/index.ts	Web entry re-exports.
packages/google-signin/src/web/gsi.ts	Web GSI script loader + typed wrapper helpers.
packages/google-signin/src/web/GoogleSignInButton.tsx	Web sign-in button component based on GSI.
packages/google-signin/src/web/GoogleAuthClient.ts	Web AuthClient implementation with storage persistence.
packages/google-signin/src/native/index.ts	Native entry re-exports (including module namespace).
packages/google-signin/src/native/GoogleSignInModule.ts	JS wrapper around the Expo native module.
packages/google-signin/src/native/GoogleSignInButton.tsx	React Native sign-in button that triggers native sign-in.
packages/google-signin/src/native/GoogleAuthClient.ts	Native AuthClient implementation with refresh support.
packages/google-signin/src/index.ts	Default (web) package root entry.
packages/google-signin/src/index.native.ts	React Native package root entry.
packages/google-signin/package.json	Defines package metadata, build/test scripts, and conditional exports.
packages/google-signin/react-auth-google.podspec	CocoaPods spec for iOS integration (package root).
packages/google-signin/ios/react-auth-google.podspec	CocoaPods spec colocated under ios/.
packages/google-signin/ios/GoogleSignInModule.swift	iOS Expo module implementation using GoogleSignIn.
packages/google-signin/expo-module.config.json	Expo module registration for iOS/Android.
packages/google-signin/android/build.gradle	Android library build config + dependencies.
packages/google-signin/android/src/main/java/expo/modules/googlesignin/GoogleSignInModule.kt	Android Expo module implementation using Credential Manager + Google Identity.
packages/google-signin/README.md	Package documentation and usage examples.

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