UI Test Gen MCP Server

A Model Context Protocol (MCP) server that generates Playwright visual testing scripts from CSV data with advanced configuration management, environment switching capabilities, and organized code structure.

🚀 Overview

This MCP server provides automated generation of Playwright visual testing scripts, helping developers quickly create comprehensive UI test suites from CSV test specifications. It includes automatic Playwright configuration validation, organized folder structure creation, intelligent code generation following best practices, and environment switching capabilities for multi-environment testing.

Related MCP server: UI Screenshot Comparison MCP

📦 Installation

Option 1: Install from npm (Recommended)

# Install globally for system-wide access
npm install -g ui-test-gen-mcp

# Or install locally in your project
npm install ui-test-gen-mcp

Option 2: Install from source

# Clone the repository
git clone <repository-url>
cd ui-test-gen-mcp

# Install dependencies
npm install

# Build the TypeScript code
npm run build

🏗️ Project Structure

ui-test-gen-mcp/
├── main.ts                 # MCP server entry point
├── tools/
│   ├── index.ts           # Tool exports
│   ├── visual-test-generator.ts  # Main test generation tool
│   └── tool-lister.ts     # Tool listing utility
├── helper/
│   ├── index.ts           # Helper function exports
│   ├── template.ts        # Test templates and tag definitions
│   ├── test-tags.ts       # Tag utility functions
│   ├── env-config.ts      # Environment configuration helpers
│   ├── test-data.ts       # Test data management
│   └── register.ts        # Tool registration helper
├── data/
│   ├── core-test-script.content.txt  # Test script template
│   └── template-usage-guide.md       # Template usage documentation
└── dist/                  # Compiled JavaScript output

🛠️ Available Tools

1. Visual Test Generator (create_playwright_visual_tests)

Purpose: Generate comprehensive Playwright visual testing scripts from CSV data

Features:

• Automatic Playwright Config Validation: Checks and updates playwright.config.ts for proper snapshotDir configuration

• Organized Folder Structure: Creates ./tests/ui/, ./utils/ui/, ./data/ui/, and ./pages/ui/ directories

• CSV-Based Test Generation: Processes CSV data to create test files following a strict template

• Environment Switching: NEW - Single test file handles multiple environments (prep, int, qa, prod, etc.)

• Smart Code Organization: Extracts utilities and organizes code during refactoring phase

• Project Style Integration: Analyzes existing code to match project's coding conventions

• Improved Tag System: NEW - Pre-calculated tag constants instead of function calls

Input Schema:

{
  csvData: string  // CSV content with test information
}

Required CSV Columns:

• file_name: Name for the generated test file

• test_url: URL to test

• test_description: Description of what to test

• test_selector: CSS selector for the element

• test_hide: Elements to hide during testing (component-specific)

• test_action: Action to perform (optional)

• test_env: NEW - Environment name (prep, int, qa, prod, staging, etc.)

2. Tool Lister (list_tools)

Purpose: Display all available tools with simple descriptions

Usage: Call this tool to see what's available in the MCP server

🔧 Key Features

Playwright Configuration Management

• Automatically validates playwright.config.ts files

• Ensures snapshotDir is set to "./__screenshots__"

• Updates configuration if missing or incorrect (only modifies snapshotDir)

Environment Switching Capabilities 🆕

• Single Test File: One test file per component handles all environments

• Dynamic Environment Config: Environment configuration generated from CSV data

• User-Controlled Switching: Users manually configure environment selection

• Flexible Environment Support: Supports any environment name (prep, int, qa, prod, staging, etc.)

Improved Screenshot Path Structure 🆕

• Clean Paths: __screenshots__/fileName/fileName.png format

• No Environment Nesting: Simple, clean structure without unnecessary directories

• Consistent Naming: Predictable and maintainable screenshot organization

Enhanced Tag System 🆕

• Pre-calculated Constants: Uses fullPageTags and sectionTags constants

• No Function Calls: Eliminates getTagsForSelector() function calls

• Proper Playwright Syntax: Implements tags using test('Name', { tag: tags }, async ({ page }) => {})

• Automatic Tag Selection: Body selector gets fullPageTags, others get sectionTags

Organized Project Structure

• ./tests/ui/ - Generated test files (single file per component)

• ./utils/ui/ - Utility functions organized by type:

  • selectors.ts - Reusable selectors and constants

  • helpers.ts - Common helper functions

  • test-actions.ts - Generated test action functions

  • page-objects.ts - Page object model patterns

  • validation.ts - Validation and error handling

  • env-config.ts - NEW Environment configuration utilities

  • test-tags.ts - NEW Tag management utilities

• ./data/ui/ - Test data and configuration

• ./pages/ui/ - Page object classes and locators

Intelligent Code Generation

• Follows the embedded core test script template strictly

• Generates proper test action functions following Playwright best practices

• Preserves component-specific test_hide selectors

• Maintains separation between test files and utility/data files

Template Compliance

The server uses a mandatory core test script template that ensures consistency:

• Standard Playwright test structure

• Proper screenshot handling with toMatchSnapshot

• Element hiding for clean visual testing

• Scroll handling for element visibility

• Proper tag implementation

📋 Workflow

Phase 1: Configuration Validation

1. Locate playwright.config.ts files in the project

2. Verify snapshotDir is set to "./__screenshots__"

3. Update configuration if necessary

Phase 2: Test File Generation

1. Parse CSV data for test specifications

2. Detect environment column and use appropriate template

3. Create single test file per component in ./tests/ui/ folder

4. Apply the core test script template with environment switching

5. Replace template variables with CSV data

Phase 3: Project Structure Creation

1. Create organized folder structure

2. Generate utility files in appropriate locations

3. Create data and page object files

4. Generate environment configuration files

Phase 4: Code Refactoring

1. Extract common utilities to grouped files

2. Organize code for maintainability

3. Follow project's existing coding style

4. Ensure proper separation of concerns

5. Implement proper tag system

🚀 Setup & Usage

Prerequisites

• Node.js (v18 or higher)

• npm or yarn

• Playwright installed in your project

Quick Start

1. Install the package:

   npm install ui-test-gen-mcp

2. Configure your MCP client (e.g., Cursor, VS Code with MCP extension):

   {
     "mcpServers": {
       "ui-test-gen-mcp": {
         "command": "npx",
         "args": ["-y", "ui-test-gen-mcp"]
       }
     }
   }

3. Alternative configuration (if using local installation):

   {
     "mcpServers": {
       "ui-test-gen-mcp": {
         "command": "node",
         "args": ["./node_modules/ui-test-gen-mcp/dist/main.js"]
       }
     }
   }

4. Restart your MCP client to load the new server

Development Setup

If you're developing or want to run from source:

# Start development mode with auto-reload
npm run dev

# Build for production
npm run build

# Start the built server
npm start

🔌 MCP Configuration Examples

For Cursor IDE

Add to your Cursor settings:

{
  "mcpServers": {
    "ui-test-gen-mcp": {
      "command": "npx",
      "args": ["-y", "ui-test-gen-mcp"]
    }
  }
}

For VS Code with MCP Extension

Add to your VS Code settings:

{
  "mcp.servers": {
    "ui-test-gen-mcp": {
      "command": "npx",
      "args": ["ui-test-gen-mcp"]
    }
  }
}

For Other MCP Clients

{
  "mcpServers": {
    "ui-test-gen-mcp": {
      "command": "npx",
      "args": ["-y", "ui-test-gen-mcp"]
    }
  }
}

🧪 Testing

Test the MCP connection:

# If installed globally
ui-test-gen-mcp

# If installed locally
npx ui-test-gen-mcp

# If running from source
node test-connection.js

📝 CSV Format Example

Basic Format

file_name,test_url,test_description,test_selector,test_hide,test_action
homepage,https://example.com,Homepage hero section,.hero-section,.ad-banner,click
product,https://example.com/product,Product image,.product-image,.cookie-banner,screenshot

NEW - With Environment Support

file_name,test_url,test_description,test_selector,test_hide,test_action,test_env
pdp,https://prep.example.com/product,PDP Full Page,body,.banner,.modal,prep
pdp,https://int.example.com/product,PDP Full Page,body,.banner,.modal,int
pdp,https://qa.example.com/product,PDP Full Page,body,.banner,.modal,qa

💡 Usage Examples

Basic Usage

Once configured, you can use the MCP server to:

1. Generate tests from CSV data:

   • Call create_playwright_visual_tests with your CSV content

   • The server will automatically create test files and folder structure

2. List available tools:

   • Call list_tools to see what's available

Example CSV Input

file_name,test_url,test_description,test_selector,test_hide,test_action,test_env
landing,https://myapp.com,Landing page header,.header-section,.notification-banner,screenshot,prep
dashboard,https://myapp.com/dashboard,Dashboard sidebar,.sidebar-nav,.ads-container,click,int

Generated Output

The server will create:

• ./tests/ui/landing.spec.ts - Single test file for landing page (handles all environments)

• ./tests/ui/dashboard.spec.ts - Single test file for dashboard (handles all environments)

• ./utils/ui/ - Organized utility files including environment config

• ./data/ui/ - Test data files

• ./pages/ui/ - Page object classes

NEW - Environment Switching Example

// Generated test file with environment switching
test.describe('Landing - Visual testing', () => {
  test('Landing page header', {
    tag: sectionTags  // Pre-calculated constant, no function call
  }, async ({ page }) => {
    const testData = landingTestData.find(t => 
      t.test_description === 'Landing page header' && 
      t.test_env === getCurrentEnv()
    );
    
    if (!testData) throw new Error('Test data not found');
    
    await page.goto(testData.test_url);
    
    // Hide elements specific to this component
    await hideElements(page, testData.test_hide);
    
    const locator = page.locator(testData.test_selector);
    await locator.scrollIntoViewIfNeeded();
    
    // Clean screenshot path structure
    const fileName = generateFileName(testData.test_description);
    expect(await locator.screenshot()).toMatchSnapshot(`${fileName}/${fileName}.png`);
  });
});

⚠️ Important Notes

Template Compliance

• The core test script template is mandatory and non-negotiable

• Never deviate from the template structure

• Always use exact import statements and test patterns

Environment Switching 🆕

• Single Test File: One test file per component handles all environments

• User Control: Users manually configure environment selection

• No Automatic Switching: switchEnvironment() calls are not automatically generated

• Flexible Implementation: Users implement getCurrentEnv() based on their configuration

Tag System 🆕

• No Function Calls: Tags use pre-calculated constants (fullPageTags, sectionTags)

• Proper Syntax: Implements Playwright tag syntax correctly

• Automatic Selection: Body selector gets fullPageTags, others get sectionTags

Component Safety

• Each CSV component maintains its own test_hide selectors

• No cross-component selector sharing

• Preserve component-specific configurations during refactoring

File Organization

• Test files must be created in ./tests/ui/ folder

• Utilities must be organized in appropriate grouped files

• Data files and page objects must be separate from .spec.ts files

🎯 Benefits

• Rapid Test Creation: Generate comprehensive test suites from CSV data

• Consistent Structure: Enforced template compliance ensures consistency

• Professional Organization: Industry-standard folder structure

• Automatic Configuration: Playwright config validation and updates

• Maintainable Code: Clean, organized, and well-structured test files

• Project Integration: Follows existing project coding styles and conventions

• Easy Installation: Available as npm package for quick setup

• Environment Support: NEW - Single test file handles multiple environments

• Clean Screenshots: NEW - Simple, organized screenshot paths

• Proper Tags: NEW - No function calls, uses pre-calculated constants

🐛 Troubleshooting

Common Issues

1. MCP Connection Failed: Ensure the server is installed and configured correctly

2. Template Errors: Verify CSV data follows required format

3. Configuration Issues: Check that playwright.config.ts exists and is editable

4. Folder Creation Errors: Ensure write permissions in the project directory

5. Environment Issues: NEW - Verify test_env column is present in CSV for environment switching

Debug Steps

1. Verify installation: npm list ui-test-gen-mcp

2. Test MCP connection: npx ui-test-gen-mcp

3. Check console logs for error messages

4. Verify CSV data format and content

5. Ensure project structure is properly set up

6. Check for environment column in CSV data

📚 Additional Resources

• Model Context Protocol Documentation

• Playwright Testing Framework

• TypeScript Documentation

• npm Package Page

🤝 Contributing

Contributions are welcome! Please ensure:

• Code follows existing patterns and style

• Tests are updated for new features

• Documentation is kept current

📄 License

ISC License - see package.json for details

Note: This MCP server is designed for generating Playwright visual testing scripts with environment switching capabilities. Ensure you have Playwright properly configured in your project before using the generated tests.

Package: Available on npm as ui-test-gen-mcp

Recent Updates:

• ✅ Environment switching capabilities

• ✅ Improved screenshot path structure

• ✅ Enhanced tag system (no function calls)

• ✅ Single test file per component

• ✅ User-controlled environment configuration