Add a demo for actions using typescript (#1212)

This PR adds a comprehensive TypeScript demo for ROS2 actions using rclnodejs. The demo implements a Fibonacci sequence calculator with both action client and server components, providing a complete example of how to use actions in TypeScript.

- Implements TypeScript action server and client for Fibonacci calculation
- Provides comprehensive documentation and setup instructions
- Includes build configuration with proper TypeScript tooling
- Fixes a minor issue in the existing JavaScript action client example

Fix: #1211

Author: minggangw

example/actions/action_client/action-client-example.js

@@ -68,13 +68,12 @@ class FibonacciActionClient {
 
 rclnodejs
   .init()
-  .then(() => {
+  .then(async () => {
     const node = rclnodejs.createNode('action_client_example_node');
     const client = new FibonacciActionClient(node);
-
-    client.sendGoal();
-
     rclnodejs.spin(node);
+
+    await client.sendGoal();
   })
   .catch((err) => {
     console.error(err);

ts_demo/actions/README.md

@@ -0,0 +1,305 @@
+# TypeScript Actions Demo for rclnodejs
+
+This demo showcases how to use ROS2 actions with rclnodejs in TypeScript. It includes both an action client and server implementation using the Fibonacci action as an example.
+
+## What are ROS2 Actions?
+
+Actions in ROS2 are a communication pattern for long-running tasks that:
+
+- Have a **goal** (what you want to achieve)
+- Provide **feedback** during execution (progress updates)
+- Return a **result** when completed (final outcome)
+- Can be **canceled** while running
+
+Actions are perfect for tasks like navigation, manipulation, or any long-running computation where you need progress updates.
+
+## Demo Overview
+
+This demo implements a Fibonacci sequence calculator using ROS2 actions:
+
+- **Action Server** (`server.ts`): Calculates Fibonacci sequences up to a given order
+- **Action Client** (`client.ts`): Sends goals to the server and receives feedback
+
+### Features
+
+- ✅ **Goal handling**: Accept/reject goals based on input validation
+- ✅ **Feedback**: Real-time progress updates during calculation
+- ✅ **Result**: Final Fibonacci sequence
+- ✅ **Cancellation**: Support for canceling running goals
+- ✅ **Error handling**: Graceful error handling and logging
+- ✅ **TypeScript**: Full type safety and modern TypeScript features
+
+## Project Structure
+
+```
+ts_demo/actions/
+├── src/
+│   ├── client.ts          # Action client implementation
+│   └── server.ts          # Action server implementation
+├── types/
+│   └── rclnodejs.d.ts     # Type definitions
+├── package.json           # Project configuration
+├── tsconfig.json          # TypeScript configuration
+├── .gitignore            # Git ignore rules
+└── README.md             # This file
+```
+
+## Prerequisites
+
+Before running this demo, ensure you have:
+
+1. **ROS2** installed (tested with ROS2 Humble/Iron/Jazzy)
+2. **Node.js** (version 16 or higher)
+3. **rclnodejs** built and configured in the parent directory (`../../`)
+4. **test_msgs** package available (usually included with ROS2)
+
+**Important**: This demo uses rclnodejs as a peer dependency, so you must ensure that the main rclnodejs package in the parent directory is properly built and configured with ROS2 before running this demo.
+
+## Setup and Installation
+
+1. **Ensure ROS2 is sourced**:
+
+   ```bash
+   source /opt/ros/humble/setup.bash  # or your ROS2 distribution
+   ```
+
+2. **Build the main rclnodejs package** (if not already done):
+
+   ```bash
+   cd ../../  # Go to main rclnodejs directory
+   npm install
+   npm run build
+   ```
+
+3. **Navigate to the demo directory**:
+
+   ```bash
+   cd ts_demo/actions
+   ```
+
+4. **Install dependencies**:
+
+   ```bash
+   npm install
+   ```
+
+5. **Build the TypeScript code**:
+   ```bash
+   npm run build
+   ```
+
+## Running the Demo
+
+### Option 1: Run Server and Client Separately
+
+1. **Start the action server** (in terminal 1):
+
+   ```bash
+   npm run start:server
+   ```
+
+   You should see output like:
+
+   ```
+   🚀 Starting TypeScript Action Server Demo...
+   ✓ rclnodejs initialized
+   ✓ Created node: /ts_action_server_demo
+   ✓ Fibonacci action server created on topic 'fibonacci'
+   ✓ Fibonacci action server is ready to receive goals
+   ```
+
+2. **Start the action client** (in terminal 2):
+
+   ```bash
+   npm run start:client
+   ```
+
+   You should see the client sending a goal and receiving feedback:
+
+   ```
+   🚀 Starting TypeScript Action Client Demo...
+   ✓ rclnodejs initialized
+   ✓ Created node: /ts_action_client_demo
+   ✓ Action server is available
+   Sending goal request for Fibonacci(10)...
+   ✓ Goal accepted by server
+   📊 Received feedback: [0, 1]
+   📊 Received feedback: [0, 1, 1]
+   ...
+   ✓ Goal succeeded! Fibonacci(10) = 0,1,1,2,3,5,8,13,21,34,55
+   ```
+
+### Option 2: Run Both Simultaneously
+
+Run both server and client together using concurrently:
+
+```bash
+npm run start:both
+```
+
+This will start both the server and client in parallel, showing interleaved output.
+
+### Option 3: Development Mode (with ts-node)
+
+For development with hot reloading:
+
+1. **Server**:
+
+   ```bash
+   npm run dev:server
+   ```
+
+2. **Client**:
+   ```bash
+   npm run dev:client
+   ```
+
+## Testing with ROS2 CLI Tools
+
+You can also test the action server using ROS2 command-line tools:
+
+1. **Start the server**:
+
+   ```bash
+   npm run start:server
+   ```
+
+2. **Send a goal using ros2 action**:
+
+   ```bash
+   ros2 action send_goal /fibonacci test_msgs/action/Fibonacci "{order: 15}"
+   ```
+
+3. **List available actions**:
+
+   ```bash
+   ros2 action list
+   ```
+
+4. **Get action info**:
+   ```bash
+   ros2 action info /fibonacci
+   ```
+
+## Available Scripts
+
+- `npm run build` - Compile TypeScript to JavaScript
+- `npm run clean` - Remove compiled files
+- `npm run start:server` - Run the action server
+- `npm run start:client` - Run the action client
+- `npm run start:both` - Run both server and client concurrently
+- `npm run dev:server` - Run server in development mode
+- `npm run dev:client` - Run client in development mode
+- `npm run check-types` - Type check without compilation
+
+## Understanding the Code
+
+### Action Server (`server.ts`)
+
+The action server implements three main callbacks:
+
+1. **Goal Callback**: Decides whether to accept or reject incoming goals
+
+   ```typescript
+   goalCallback(goalHandle: any): rclnodejs.GoalResponse {
+     // Validate the goal and return ACCEPT or REJECT
+   }
+   ```
+
+2. **Execute Callback**: Performs the actual work (Fibonacci calculation)
+
+   ```typescript
+   async executeCallback(goalHandle: any): Promise<any> {
+     // Calculate Fibonacci sequence and provide feedback
+   }
+   ```
+
+3. **Cancel Callback**: Handles goal cancellation requests
+   ```typescript
+   cancelCallback(goalHandle: any): rclnodejs.CancelResponse {
+     // Return ACCEPT to allow cancellation
+   }
+   ```
+
+### Action Client (`client.ts`)
+
+The action client:
+
+1. Waits for the action server to be available
+2. Creates and sends a goal
+3. Handles feedback during execution
+4. Processes the final result
+
+```typescript
+const goalHandle = await this.actionClient.sendGoal(goal, (feedback) =>
+  this.feedbackCallback(feedback)
+);
+```
+
+## Customization
+
+You can modify the demo to:
+
+- **Change the Fibonacci order**: Edit `FIBONACCI_ORDER` in `client.ts`
+- **Adjust timing**: Modify the delay in the server's execute callback
+- **Add validation**: Enhance goal validation in the server
+- **Handle errors**: Add more sophisticated error handling
+
+## Troubleshooting
+
+### Common Issues
+
+1. **"Cannot find module 'rclnodejs'"**:
+
+   - Ensure rclnodejs is properly built in the parent directory
+   - Run `npm install` in the main rclnodejs directory
+
+2. **"Action server not available"**:
+
+   - Make sure the action server is running before starting the client
+   - Check that both nodes are using the same action name
+
+3. **TypeScript compilation errors**:
+
+   - Run `npm run check-types` to see detailed type errors
+   - Ensure all dependencies are installed: `npm install`
+
+4. **ROS2 environment not sourced**:
+   ```bash
+   source /opt/ros/humble/setup.bash  # or your ROS2 distribution
+   ```
+
+### Debugging
+
+Enable debug logging by setting the environment variable:
+
+```bash
+export RCUTILS_LOGGING_SEVERITY=DEBUG
+npm run start:server
+```
+
+## Next Steps
+
+After exploring this demo, you might want to:
+
+1. **Create custom actions**: Define your own `.action` files
+2. **Handle multiple goals**: Implement concurrent goal handling
+3. **Add persistence**: Store goal state across restarts
+4. **Integrate with other nodes**: Combine actions with topics and services
+5. **Add visualization**: Create a web interface to monitor action progress
+
+## Related Examples
+
+- **Topics Demo**: `../topics/` - Publisher/Subscriber pattern
+- **Services Demo**: `../services/` - Request/Response pattern
+- **JavaScript Actions**: `../../example/actions/` - JavaScript implementation
+
+## Resources
+
+- [ROS2 Actions Documentation](https://docs.ros2.org/latest/Tutorials/Understanding-ROS2-Actions.html)
+- [rclnodejs Documentation](https://github.com/RobotWebTools/rclnodejs)
+- [test_msgs Package](https://github.com/ros2/rcl_interfaces/tree/master/test_msgs)
+
+---
+
+**Happy coding with ROS2 Actions and TypeScript! 🚀**

ts_demo/actions/package.json

@@ -0,0 +1,44 @@
+{
+  "name": "rclnodejs-ts-actions-demo",
+  "version": "1.0.0",
+  "description": "TypeScript demo for rclnodejs actions (client and server)",
+  "main": "dist/client.js",
+  "scripts": {
+    "prebuild": "npm run clean",
+    "build": "tsc",
+    "start:server": "npm run build && node dist/server.js",
+    "start:client": "npm run build && node dist/client.js",
+    "start:both": "npm run build && concurrently \"node dist/server.js\" \"node dist/client.js\"",
+    "clean": "rimraf dist",
+    "dev:server": "ts-node src/server.ts",
+    "dev:client": "ts-node src/client.ts",
+    "check-types": "tsc --noEmit"
+  },
+  "keywords": [
+    "rclnodejs",
+    "ros2",
+    "typescript",
+    "client",
+    "server",
+    "action",
+    "fibonacci",
+    "demo"
+  ],
+  "author": "rclnodejs contributors",
+  "license": "Apache-2.0",
+  "devDependencies": {
+    "@types/node": "^22.16.5",
+    "concurrently": "^9.2.0",
+    "rimraf": "^6.0.1",
+    "ts-node": "^10.9.2",
+    "typescript": "^5.8.3"
+  },
+  "peerDependencies": {
+    "rclnodejs": "^1.0.0"
+  },
+  "peerDependenciesMeta": {
+    "rclnodejs": {
+      "optional": false
+    }
+  }
+}