Test Runner MCP

A Model Context Protocol (MCP) server for running and parsing test results from multiple testing frameworks. This server provides a unified interface for executing tests and processing their outputs, supporting:

• Bats (Bash Automated Testing System)

• Pytest (Python Testing Framework)

• Flutter Tests

• Jest (JavaScript Testing Framework)

• Go Tests

• Rust Tests (Cargo test)

• Generic (for arbitrary command execution)

Installation

npm install test-runner-mcp

Related MCP server: Tailscale MCP Server

Prerequisites

The following test frameworks need to be installed for their respective test types:

• Bats: apt-get install bats or brew install bats

• Pytest: pip install pytest

• Flutter: Follow Flutter installation guide

• Jest: npm install --save-dev jest

• Go: Follow Go installation guide

• Rust: Follow Rust installation guide

Usage

Configuration

Add the test-runner to your MCP settings (e.g., in claude_desktop_config.json or cline_mcp_settings.json):

{
  "mcpServers": {
    "test-runner": {
      "command": "node",
      "args": ["/path/to/test-runner-mcp/build/index.js"],
      "env": {
        "NODE_PATH": "/path/to/test-runner-mcp/node_modules",
        // Flutter-specific environment (required for Flutter tests)
        "FLUTTER_ROOT": "/opt/homebrew/Caskroom/flutter/3.27.2/flutter",
        "PUB_CACHE": "/Users/username/.pub-cache",
        "PATH": "/opt/homebrew/Caskroom/flutter/3.27.2/flutter/bin:/usr/local/bin:/usr/bin:/bin"
      }
    }
  }
}

Note: For Flutter tests, ensure you replace:

• /opt/homebrew/Caskroom/flutter/3.27.2/flutter with your actual Flutter installation path

• /Users/username/.pub-cache with your actual pub cache path

• Update PATH to include your system's actual paths

You can find these values by running:

# Get Flutter root
flutter --version

# Get pub cache path
echo $PUB_CACHE   # or default to $HOME/.pub-cache

# Get Flutter binary path
which flutter

Running Tests

Use the run_tests tool with the following parameters:

{
  "command": "test command to execute",
  "workingDir": "working directory for test execution",
  "framework": "bats|pytest|flutter|jest|go|rust|generic",
  "outputDir": "directory for test results",
  "timeout": "test execution timeout in milliseconds (default: 300000)",
  "env": "optional environment variables",
  "securityOptions": "optional security options for command execution"
}

Example for each framework:

// Bats
{
  "command": "bats test/*.bats",
  "workingDir": "/path/to/project",
  "framework": "bats",
  "outputDir": "test_reports"
}

// Pytest
{
  "command": "pytest test_file.py -v",
  "workingDir": "/path/to/project",
  "framework": "pytest",
  "outputDir": "test_reports"
}

// Flutter
{
  "command": "flutter test test/widget_test.dart",
  "workingDir": "/path/to/project",
  "framework": "flutter",
  "outputDir": "test_reports",
  "FLUTTER_ROOT": "/opt/homebrew/Caskroom/flutter/3.27.2/flutter",
  "PUB_CACHE": "/Users/username/.pub-cache",
  "PATH": "/opt/homebrew/Caskroom/flutter/3.27.2/flutter/bin:/usr/local/bin:/usr/bin:/bin"
}

// Jest
{
  "command": "jest test/*.test.js",
  "workingDir": "/path/to/project",
  "framework": "jest",
  "outputDir": "test_reports"
}

// Go
{
  "command": "go test ./...",
  "workingDir": "/path/to/project",
  "framework": "go",
  "outputDir": "test_reports"
}

// Rust
{
  "command": "cargo test",
  "workingDir": "/path/to/project",
  "framework": "rust",
  "outputDir": "test_reports"
}

// Generic (for arbitrary commands, CI/CD tools, etc.)
{
  "command": "act -j build",
  "workingDir": "/path/to/project",
  "framework": "generic",
  "outputDir": "test_reports"
}

// Generic with security overrides
{
  "command": "sudo docker-compose -f docker-compose.test.yml up",
  "workingDir": "/path/to/project",
  "framework": "generic",
  "outputDir": "test_reports",
  "securityOptions": {
    "allowSudo": true
  }
}

Security Features

The test-runner includes built-in security features to prevent execution of potentially harmful commands, particularly for the generic framework:

1. Command Validation

   • Blocks sudo and su by default

   • Prevents dangerous commands like rm -rf /

   • Blocks file system write operations outside of safe locations

2. Environment Variable Sanitization

   • Filters out potentially dangerous environment variables

   • Prevents overriding critical system variables

   • Ensures safe path handling

3. Configurable Security

   • Override security restrictions when necessary via securityOptions

   • Fine-grained control over security features

   • Default safe settings for standard test usage

Security options you can configure:

{
  "securityOptions": {
    "allowSudo": false,        // Allow sudo commands
    "allowSu": false,          // Allow su commands
    "allowShellExpansion": true, // Allow shell expansion like $() or backticks
    "allowPipeToFile": false   // Allow pipe to file operations (> or >>)
  }
}

Flutter Test Support

The test runner includes enhanced support for Flutter tests:

1. Environment Setup

   • Automatic Flutter environment configuration

   • PATH and PUB_CACHE setup

   • Flutter installation verification

2. Error Handling

   • Stack trace collection

   • Assertion error handling

   • Exception capture

   • Test failure detection

3. Output Processing

   • Complete test output capture

   • Stack trace preservation

   • Detailed error reporting

   • Raw output preservation

Rust Test Support

The test runner provides specific support for Rust's cargo test:

1. Environment Setup

   • Automatically sets RUST_BACKTRACE=1 for better error messages

2. Output Parsing

   • Parses individual test results

   • Captures detailed error messages for failed tests

   • Identifies ignored tests

   • Extracts summary information

Generic Test Support

For CI/CD pipelines, GitHub Actions via act, or any other command execution, the generic framework provides:

1. Automatic Output Analysis

   • Attempts to segment output into logical blocks

   • Identifies section headers

   • Detects pass/fail indicators

   • Provides reasonable output structure even for unknown formats

2. Flexible Integration

   • Works with arbitrary shell commands

   • No specific format requirements

   • Perfect for integration with tools like act, Docker, and custom scripts

3. Security Features

   • Command validation to prevent harmful operations

   • Can be configured to allow specific elevated permissions when necessary

Output Format

The test runner produces structured output while preserving complete test output:

interface TestResult {
  name: string;
  passed: boolean;
  output: string[];
  rawOutput?: string;  // Complete unprocessed output
}

interface TestSummary {
  total: number;
  passed: number;
  failed: number;
  duration?: number;
}

interface ParsedResults {
  framework: string;
  tests: TestResult[];
  summary: TestSummary;
  rawOutput: string;  // Complete command output
}

Results are saved in the specified output directory:

• test_output.log: Raw test output

• test_errors.log: Error messages if any

• test_results.json: Structured test results

• summary.txt: Human-readable summary

Development

Setup

1. Clone the repository

2. Install dependencies:

   npm install

3. Build the project:

   npm run build

Running Tests

npm test

The test suite includes tests for all supported frameworks and verifies both successful and failed test scenarios.

CI/CD

The project uses GitHub Actions for continuous integration:

• Automated testing on Node.js 18.x and 20.x

• Test results uploaded as artifacts

• Dependabot configured for automated dependency updates

Contributing

1. Fork the repository

2. Create your feature branch

3. Commit your changes

4. Push to the branch

5. Create a Pull Request

License

This project is licensed under the MIT License - see the LICENSE file for details.