@stevenleep/sandbox/example/shadowrealm-demo.ts

A powerful JavaScript sandbox library that provides multiple sandbox implementation options for safely executing untrusted code in browser environments.

// Sample ShadowRealm Sandbox demo
import { ShadowRealmSandbox } from '../src';

/**
 * This example demonstrates how to use the ShadowRealmSandbox
 * featuring security controls, memory management, and resource limits
 */
async function shadowRealmDemo() {
  console.log('🚀 ShadowRealm Sandbox Demo');
  console.log('------------------------------');

  // Create a ShadowRealm sandbox with security and resource limits
  const sandbox = new ShadowRealmSandbox({
    name: 'demo-shadowrealm',
    // Use iframe fallback for better compatibility
    forceIframe: true,
    // Set execution timeout
    timeLimit: 3000,
    // Enable strict mode
    strictMode: true,
    // Enable performance measurement
    enablePerformanceMeasure: true,
    // Security configuration
    security: {
      // Prevent access to sensitive APIs
      preventSensitiveAPIs: true,
      // Block network access
      allowNetwork: false
    },
    // Custom error handler
    errorHandler: (error, code) => {
      console.error('🛑 Sandbox execution error:', error.message);
      console.log('Problematic code:', code);
    }
  });

  // Activate the sandbox
  sandbox.activate();
  
  // Basic code execution
  console.log('\n📋 Basic Execution:');
  const result = sandbox.execScript(`
    const a = 5;
    const b = 7;
    return a + b;
  `);
  console.log('Result:', result);

  // Demonstrate isolation
  console.log('\n🔒 Demonstrating Isolation:');
  sandbox.execScript(`window.isolationTest = 'This should be contained';`);
  console.log('In sandbox:', sandbox.execScript(`return window.isolationTest;`));
  console.log('In main context:', typeof (window as any).isolationTest);

  // Demonstrate security features
  console.log('\n🛡️ Demonstrating Security Features:');
  try {
    sandbox.execScript(`
      try {
        // Attempt to access fetch API (should be restricted)
        return typeof fetch;
      } catch (e) {
        return e.message;
      }
    `);
  } catch (error) {
    console.log('Security restriction in action:', error);
  }

  // Demonstrate function export and import
  console.log('\n🔄 Demonstrating Function Export/Import:');
  
  // Export a function from main context to sandbox
  const multiplyFn = (a: number, b: number) => a * b;
  sandbox.exportFunction('multiply', multiplyFn);
  
  // Use the exported function in the sandbox
  const multiplyResult = sandbox.execScript(`
    return multiply(5, 7);
  `);
  console.log('Using exported function in sandbox:', multiplyResult);
  
  // Define a function in the sandbox
  sandbox.execScript(`
    function add(a, b) {
      return a + b;
    }
  `);
  
  // Import the function from sandbox to main context
  const addFn = sandbox.importFunction('add');
  console.log('Using imported function in main context:', addFn(10, 20));

  // Demonstrate async execution with timeout
  console.log('\n⏱️ Demonstrating Async Execution with Timeout:');
  try {
    const asyncResult = await sandbox.execScriptAsync(`
      return new Promise(resolve => {
        setTimeout(() => {
          resolve('Async operation completed');
        }, 100);
      });
    `, 500);
    console.log('Async result:', asyncResult);
  } catch (error) {
    console.error('Async execution error:', error);
  }

  // Demonstrate timeout for long-running operations
  console.log('\n⏰ Demonstrating Timeout for Long-Running Operations:');
  try {
    await sandbox.execScriptAsync(`
      // This should timeout after 1 second
      return new Promise(resolve => {
        let counter = 0;
        const interval = setInterval(() => {
          counter++;
          if (counter >= 1000) {
            clearInterval(interval);
            resolve('This should never resolve');
          }
        }, 10);
      });
    `, 1000);
  } catch (error) {
    console.log('Timeout worked:', error.message);
  }

  // Clean up resources
  console.log('\n🧹 Cleaning Up Resources:');
  console.log('Deactivating and destroying sandbox...');
  sandbox.deactivate();
  sandbox.destroy();
  console.log('Sandbox destroyed.');

  console.log('\n✅ ShadowRealm Sandbox Demo Completed');
}

// Run the demo
shadowRealmDemo()
  .catch(error => console.error('Demo failed:', error));