Workaround MaxItems not working for AWS Lambda listFunctions method

index.js

// https://github.com/aws/aws-sdk-js/issues/1118

const AWS = require('aws-sdk')
const instance = new AWS.Lambda()

function listFunctionsReally (lambda, params = {}) {
  return new Promise((resolve, reject) => {
    const req = lambda.listFunctions(params)
    const results = []
    const { MaxItems = 50 } = params

    // returning `false` will stop `eachPage` from requesting more results
    req.eachPage((error, data) => {
      if (error) {
        reject(error)

        return false
      } else if (data) {
        const length = data.Functions.length

        for (let i = 0; i < length; i++) {
          if (results.length >= MaxItems) {
            // stop at MaxItems if we have achieved it
            resolve(results)

            return false
          }

          results.push(data.Functions[ i ])
        }
      } else {
        // data may be `null` if the page that was requested does not exist
        // this happens when `MaxItems` is more than the number of lambdas
        // causing a page to be null
        resolve(results)

        return false
      }
    })
  })
}

listFunctionsReally(instance, { MaxItems: 100 })
  .then(console.log, console.error)