rn-bridge-to-turbo

Convert React Native Bridge modules into Codegen-ready TurboModule specs automatically.

🚀 Why use this?

Migrating from Bridge modules to TurboModules is manual, repetitive, and error-prone.

This CLI helps you:

• ⚡ Automatically generate TurboModule specs
• 🔍 Detect native module methods
• 🧠 Map Java/Kotlin types to Codegen-compatible types
• 🧩 Preserve method signatures and overloads

⚙️ Usage

npx rn-bridge-to-turbo scan .

More options:

npx rn-bridge-to-turbo --help
npx rn-bridge-to-turbo scan . --include-node-modules
npx rn-bridge-to-turbo scan . --out-dir ./specs
npx rn-bridge-to-turbo scan . --debug

📦 What it does

• Scans your React Native project for native modules (.java, .kt)
• Detects methods annotated with @ReactMethod
• Converts them into TurboModule TypeScript specs
• Generates files inside:

generated/specs/
  NativeMyModule.ts
  NativeMyKotlinModule.ts

🧾 Example Output

export interface NativeMyModuleSpec extends TurboModule {
  getData(id: string): Promise<unknown>;
  sendEvent(name: string, value: Int32): void;
}

🛠 Install

npm install
npm run build

Global usage:

npm install -g .
rn-bridge-to-turbo scan <path>

⚡ React Native Codegen Setup

The CLI automatically ensures codegenConfig exists in your package.json.

"codegenConfig": {
  "name": "AppSpecs",
  "type": "modules",
  "jsSrcsDir": "generated/specs"
}

🧠 Type Mapping

• String → string
• int → Int32
• double → Double
• long → unknown
• Map → UnsafeObject
• List<T> → ReadonlyArray<T>

Promise handling:

• Inferred when possible
• Falls back to Promise<unknown>

📌 Notes

• Java parsing uses AST (with fallback for edge cases)
• Kotlin parsing is currently regex-based
• Some complex signatures may need manual refinement

✅ Example CLI Output

[scan] Scanning project /path/to/app
[scan] Found 12 source file(s)
[scan] Writing specs to /generated/specs
[ok] Generated NativeMyModule.ts
[warn] Skipped 3 file(s)
[ok] Done! Generated 5 module(s)