1.Request Validator

function requestValidator(requestObj) {
    const validMethods = ['GET', 'POST', 'DELETE', 'CONNECT'];
    const validVersion = ['HTTP/0.9', 'HTTP/1.0', 'HTTP/1.1', 'HTTP/2.0'];
    const regexURI = /^[a-zA-Z0-9.*]+$/;
    const regexMessage = /^[^<>\\&'"\r\n]*$/;

    if (requestObj.hasOwnProperty('method')) {
      if (!validMethods.includes(requestObj.method)) {
        throw new Error('Invalid request header: Invalid Method');
      }
    } else {
      throw new Error('Invalid request header: Invalid Method');
    }

    if (requestObj.hasOwnProperty('uri')) {
      if (!requestObj.uri.match(regexURI)) {
        throw new Error('Invalid request header: Invalid URI');
      }
    } else {
      throw new Error('Invalid request header: Invalid URI');
    }

    if (requestObj.hasOwnProperty('version')) {
      if (!validVersion.includes(requestObj.version)) {
        throw new Error('Invalid request header: Invalid Version');
      }
    } else {
      throw new Error('Invalid request header: Invalid Version');
    }

    if (requestObj.hasOwnProperty('message')) {
      if (!requestObj.message.match(regexMessage) && requestObj.message !== '') {
        throw new Error('Invalid request header: Invalid Message');
      }
    } else {
      throw new Error('Invalid request header: Invalid Message');
    }

    return requestObj;
  }