Optional chaining and Nullish coalescing operators in AWS Lambda Node.js 14

Node.js 14 introduces some new features and concepts. Highlights:

• Nullish coalescing. This introduces ?? which is safer than using || for assignment (as it only evaluates to false for null or undefined).

• Optional chaining. This introduces ?. which allows safe access to deep keys on objects that may not exist.

The simplest AWS Lambda function that uses both these features:

// AWS_LAMBDA_JS_RUNTIME = 'nodejs14.x'
exports.handler = async event => {
  const name = event?.queryStringParameters?.name ?? 'World'
  return {
    statusCode: 200,
    body: `Hello, ${name}`,
  }
}

Result:

// example.com/endpoint?name=John
'Hello, John'
// example.com/endpoint
'Hello, World'