Atomic counter using AWS, Typescript/Node + AWS

gistfile1.txt

// ATOMIC COUNTER
// no other operations can happen before or after state of the data being modified
const updateParams: DocumentClient.UpdateItemInput = {
    TableName: GENERIC_TABLE,
    Key: { pk: `ORG#${organizationId}`, sk: `USER#${userId}` },
    ReturnValues: 'UPDATED_NEW',
    UpdateExpression: 'SET #itemCounter = if_not_exists(#itemCounter, :start) + :inc, #activeItems = if_not_exists(#activeItems, :start) + :inc',
    ExpressionAttributeNames: {
      '#itemCounter': 'itemCounter',
      '#activeItems': 'activeItems'
    },
    ExpressionAttributeValues: {
      ':inc': 1,
      ':start': 0
    }
};
const updateResult = await dynamo.update(updateParams).promise();