update.js

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: {
      userId: event.requestContext.identity.cognitoIdentityId,
      noteId: event.pathParameters.id
    },
    UpdateExpression: "SET content = :content, attachment = :attachment",
    ExpressionAttributeValues: {
      ":attachment": data.attachment ? data.attachment : null,
      ":content": data.content ? data.content : null
    }
  }

  try {
    const result = await dynamoDbLib.call("update", params);
    callback(null, success({status: true}));
  } catch (e) {
    console.log(e);
    callback(null, success({status: false}));
  }
}