Lambda to update all DynamoDB data to force reindex ElasticSearch AppSync Amplify

update.js

const { DynamoDB } = require("aws-sdk");
const ddb = new DynamoDB.DocumentClient();

/**
 * @param event.TableName required - DynamoDB table name
 * @param event.ExclusiveStartKey optional - Last Id if you want continue previeus execution
 * Permissions to lambda: 
 *   - dynamodb:Scan
 *   - dynamodb:BatchWriteItem
 **/

exports.lambdaHandler = async (event, context) => {
  console.log(event);
  return await update(event.TableName, event.ExclusiveStartKey);
};

const update = async (TableName, ExclusiveStartKey) => {
  try {
    while (true) {
      const params = {
        TableName,
        ExclusiveStartKey,
        Limit: 25
      };

      const data = await ddb.scan(params).promise();
      ExclusiveStartKey = data.LastEvaluatedKey;

      const saved = await updatePage(TableName, data.Items);
      console.log(saved, ExclusiveStartKey);

      if (!ExclusiveStartKey) {
        return "Ok";
      }
    }
  } catch (error) {
    console.log(error);
    return "Error";
  }
};

const updatePage = async (TableName, items) => {
  const updatedAt = new Date().toISOString();

  const params = {
    RequestItems: {}
  };

  params.RequestItems[TableName] = items.map(Item => {
    return {
      PutRequest: {
        Item: { ...Item, updatedAt }
      }
    };
  });

  return ddb.batchWrite(params).promise();
};