Implement Mock Testing Harness for Video Server with Undici Interceptors

[Copilot]

This PR implements a comprehensive mock testing harness for intercepting undici requests to the MediaMTX video server, addressing the need for reliable testing of video lease functionality without requiring a real video server.

Problem

The existing video-lease.srv.test.ts test file was making real HTTP requests to a video server, which:

• Required external dependencies for testing
• Made tests unreliable and environment-dependent
• Prevented comprehensive testing of different video server scenarios
• Limited ability to test error conditions and edge cases

Solution

Created a MockVideoServer class that uses undici's MockAgent to intercept HTTP requests and provide realistic mock responses for all MediaMTX API endpoints used by CloudTAK:

Key Features

Comprehensive Endpoint Coverage:

• /v3/config/global/get - Global video server configuration
• /v3/paths/list - List active video paths
• /v3/config/paths/add/{path} - Add new video path
• /v3/paths/get/{path} - Get path information
• /v3/config/paths/patch/{path} - Update path configuration
• /v3/config/paths/delete/{path} - Delete video path
• /v3/recordings/get/{path} - Get recording information

Stateful Simulation:

• Maintains internal state for video paths and configurations
• Supports dynamic response generation based on current state
• Provides helper methods for manipulating mock state during tests

Testing Utilities:

// Add paths with custom properties
mockVideoServer.addPath('test-stream', {
    ready: true,
    tracks: ['video', 'audio'],
    readers: [{ type: 'hls', id: 'viewer-1' }]
});

// Simulate different scenarios
mockVideoServer.setPathReady('test-stream', false);
mockVideoServer.simulateError('/v3/config/global/get', 500);

Implementation Details

The mock server uses undici's MockAgent with persistent interceptors to handle requests:

import { MockAgent, setGlobalDispatcher } from 'undici';

// Intercept requests to video server
this.mockAgent = new MockAgent();
this.mockAgent.disableNetConnect();
setGlobalDispatcher(this.mockAgent);

// Setup persistent interceptors for all endpoints
pool.intercept({
    path: '/v3/paths/list',
    method: 'GET'
}).reply(() => ({
    statusCode: 200,
    data: JSON.stringify({
        itemCount: this.paths.size,
        items: Array.from(this.paths.values())
    })
})).persist();

Test Coverage

• Unit Tests: 32 comprehensive tests covering all MockVideoServer functionality
• Integration Tests: Demonstrates successful interception of video service requests
• Error Handling: Tests for non-existent paths, server errors, and edge cases
• State Management: Verifies proper cleanup and reset functionality

Files Added/Modified

• api/test/mock-video-server.ts - Core MockVideoServer implementation
• api/test/mock-video-server.test.ts - Comprehensive test suite (32 tests)
• api/test/video-lease.srv.test.ts - Updated to demonstrate mock usage
• api/test/README-MockVideoServer.md - Complete documentation and usage guide
• api/lib/control/video-service.ts - Fixed return type for runOnDemand method

Usage Example

import MockVideoServer from './mock-video-server.js';

const mockVideoServer = new MockVideoServer({
    url: 'http://media:8080',
    configured: true
});

// Video service requests are now intercepted and mocked
const videoControl = new VideoServiceControl(config);
const configuration = await videoControl.configuration(); // Uses mock responses

mockVideoServer.close(); // Cleanup

This implementation provides a robust foundation for testing video-related functionality in CloudTAK without external dependencies, enabling more reliable and comprehensive test coverage.

---

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