Building you first Serverless app in Node.js with AWS Lambda + S3 + API Gateway

serverless-app-2.js

exports.handler = async (event) => {
    const operation = event.queryStringParameters ? event.queryStringParameters.operation : null;
    let data = JSON.parse(event.body);
    switch (operation) {
      case 'ping':
        return sendRes(200, 'pong');
      case 'convert':
        return await operate(data);
      default:
        return sendRes(401, `Unrecognized operation "${operation}"`);
    }
};

const sendRes = (status, body) => {
  var response = {
    statusCode: status,
    headers: {
      "Content-Type": "text/html"
    },
    body: body
  };
  return response;
};

const operate = async (body) => {
    return sendRes(200, 'convert is called');
};