text: import * as dynamoDbLib from './libs/dynamodb-lib';
  import { success, failure } from './libs/response-lib';
  
  export async function main(event, context, callback) {
    const data = JSON.parse(event.body);
    const params = {
      TableName: 'notes',
      // 'Key' defines the partition key and sort key of the item to be updated
      // - 'userId': Identity Pool identity id of the authenticated user
      // - 'noteId': path parameter
      Key: {
        userId: event.requestContext.identity.cognitoIdentityId,
        noteid: event.pathParameters.id,
      },
      // 'UpdateExpression' defines the attributes to be updated
      // 'ExpressionAttributeValues' defines the value in the update expression
      UpdateExpression: 'SET content = :content, attachment = :attachment',
      ExpressionAttributeValues: {
        ':attachment': data.attachment ? data.attachment : null,
        ':content': data.content ? data.content : null,
      },
      ReturnValues: 'ALL_NEW',
    };
  
    try {
      const result = await dynamoDbLib.call('update', params);
      callback(null, success({ status: true }));
    } catch (e) {
      callback(null, failure({ status: false }));
    }
  }
  