Add Comprehensive Testing Suite

[avrabe]

Epic: Testing and Quality Assurance

Priority: Low
Story Points: 10
Phase: 4 (Polish & Optimization)

Problem

The extensive ready-to-use infrastructure and planned features lack comprehensive test coverage.

Solution

Create comprehensive testing suite covering all implemented features and ready-to-use infrastructure.

Implementation Details

Testing targets:

• All 39 planned features and their infrastructure
• MCP client streaming and notification systems
• WASM component lifecycle and execution
• WIT interface rendering and editing
• Dialog system and UI interactions

Tasks

• Add unit tests for all major feature modules
• Create integration tests for MCP streaming workflows
• Add component tests for UI interactions
• Implement end-to-end tests for complete workflows
• Add performance tests for rendering and execution

Testing Structure

// Unit tests
describe('McpClient', () => {
    test('streaming listeners are managed correctly', () => {
        // Test addStreamListener/removeStreamListener
    });
    
    test('notifications are handled properly', () => {
        // Test handleNotification infrastructure
    });
});

// Integration tests  
describe('WASM Component Workflow', () => {
    test('component upload with validation', async () => {
        // Test showValidation infrastructure
    });
    
    test('component execution monitoring', async () => {
        // Test openComponentExecutionView
    });
});

// E2E tests
describe('Complete Diagram Workflows', () => {
    test('create diagram with MCP streaming', () => {
        // Test full workflow from creation to streaming updates
    });
    
    test('component execution with debugging', () => {
        // Test execution monitoring and debugging features
    });
});

// Performance tests
describe('Rendering Performance', () => {
    test('large diagram rendering with optimization hints', () => {
        // Test getViewModeRenderingHints performance
    });
});

Test Categories

• Unit Tests: Individual feature modules and utilities
• Integration Tests: Feature interactions and workflows
• Component Tests: UI component behavior and interactions
• E2E Tests: Complete user workflows
• Performance Tests: Rendering and execution benchmarks
• Accessibility Tests: Screen reader and keyboard navigation

Acceptance Criteria

• Test coverage exceeds 80% for all major features
• All ready-to-use infrastructure is tested
• CI/CD pipeline runs tests automatically
• Performance regressions are caught by tests
• Accessibility requirements are validated

Technical Notes

• Use Jest for unit and integration tests
• Use React Testing Library for component tests
• Use Playwright or Cypress for E2E tests
• Implement visual regression testing for UI components
• Add performance benchmarking with automated alerts

Files:

• All feature implementation files need test coverage
• Test utilities and fixtures for WASM/WIT components