delete all items in dynanodb table

dynamo-delete-items

#! /usr/bin/env node

const aws = require('aws-sdk')

const TABLE_NAME = process.argv[2]

if (!TABLE_NAME) {
  console.log('usage: ./dynamo-delete-items <table>')
  process.exit(1)
}

const DYNAMO_BATCH_LIMIT = 25

const dynamodbClient = new aws.DynamoDB.DocumentClient({ region: 'us-east-1' })

const batchWrite = params => dynamodbClient.batchWrite(params).promise()

const mapDeleteRequest = items =>
  items.map(item => ({
    DeleteRequest: {
      Key: {
        id: item.id
      }
    }
  }))

const batchWriteChunks = async items => {
  const chunks = chunk(DYNAMO_BATCH_LIMIT, items)

  for (let i = 0; i < chunks.length; i++) {
    await batchWrite({
      RequestItems: {
        [TABLE_NAME]: mapDeleteRequest(chunks[i])
      }
    })
  }
}

const chunk = (size, arr) => {
  const data = []
  for (let i = 0; i < arr.length; i += size) {
    data.push(arr.slice(i, size + i))
  }
  return data
}

const getAllItems = async (params = {}) => {
  const scanResults = []
  let items

  do {
    items = await dynamodbClient.scan({ TableName: TABLE_NAME }).promise()
    items.Items.forEach(item => scanResults.push(item))
    params.ExclusiveStartKey = items.LastEvaluatedKey
  } while (typeof items.LastEvaluatedKey != 'undefined')

  return scanResults
}

function main() {
  getAllItems()
    .then(batchWriteChunks)
    .then(() => {
      console.log('[SUCCESS]', `All items deleted in ${TABLE_NAME}`)
      process.exit(0)
    })
    .catch(err => {
      console.log('[ERROR]', err)
      process.exit(1)
    })
}

main()