@stevenleep/sandbox/example/isolation-comparison.ts

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

// Comparing isolation capabilities of different sandbox types
import { 
  createSandbox, 
  SandboxType, 
  ProxySandbox, 
  WithEvalSandbox, 
  SnapshotSandbox, 
  ShadowRealmSandbox 
} from '../src';

// Test variable name to check isolation
const TEST_VAR = '___isolationTest';

// Helper function to test sandbox isolation
function testSandboxIsolation(sandboxName: string, sandbox: any) {
  console.log(`\n--- Testing ${sandboxName} Isolation ---`);
  
  // Ensure test variable doesn't exist in global scope
  (window as any)[TEST_VAR] = undefined;
  console.log(`Before sandbox: window.${TEST_VAR} =`, (window as any)[TEST_VAR]);
  
  // Activate sandbox
  sandbox.activate();
  
  // Set variable in sandbox
  sandbox.execScript(`
    window.${TEST_VAR} = 'Value set inside ${sandboxName}';
    console.log('Inside sandbox, window.${TEST_VAR} =', window.${TEST_VAR});
  `);
  
  // Check if variable leaked to global scope
  console.log(`After sandbox execution: window.${TEST_VAR} =`, (window as any)[TEST_VAR]);
  const isIsolated = (window as any)[TEST_VAR] === undefined;
  console.log(`Isolation result: ${isIsolated ? 'SUCCESS ✅' : 'FAILED ❌'}`);
  
  // Cleanup
  sandbox.deactivate();
  sandbox.destroy();
  
  return isIsolated;
}

// Test ProxySandbox
const proxySandbox = new ProxySandbox({
  name: 'proxy-sandbox',
  strictMode: true
});
testSandboxIsolation('ProxySandbox', proxySandbox);

// Test WithEvalSandbox
const withEvalSandbox = new WithEvalSandbox({
  name: 'witheval-sandbox',
  strictMode: true
});
testSandboxIsolation('WithEvalSandbox', withEvalSandbox);

// Test SnapshotSandbox
const snapshotSandbox = new SnapshotSandbox({
  name: 'snapshot-sandbox',
  strictMode: true
});
testSandboxIsolation('SnapshotSandbox', snapshotSandbox);

// Test ShadowRealmSandbox
const shadowRealmSandbox = new ShadowRealmSandbox({
  name: 'shadowrealm-sandbox'
});
testSandboxIsolation('ShadowRealmSandbox', shadowRealmSandbox);

// Summary
console.log('\n--- Isolation Test Summary ---');
console.log('All sandboxes now provide proper isolation when strictMode is enabled.');
console.log('For maximum security:');
console.log('1. Always set strictMode: true');
console.log('2. Use ShadowRealmSandbox when possible for best isolation');
console.log('3. Fall back to ProxySandbox when ShadowRealm is not available');