Remove Node.js v8 support (#1402)

.ci/test-matrix.yml

@@ -6,7 +6,6 @@ NODE_JS_VERSION:
   - 14
   - 12
   - 10
-  - 8
 
 TEST_SUITE:
   - free

.github/workflows/nodejs.yml

@@ -40,31 +40,6 @@ jobs:
       run: |
         npm run test:types
 
-  test-node-v8:
-    name: Test
-    runs-on: ${{ matrix.os }}
-
-    strategy:
-      matrix:
-        node-version: [8.x]
-        os: [ubuntu-latest, windows-latest, macOS-latest]
-
-    steps:
-    - uses: actions/checkout@v2
-
-    - name: Use Node.js ${{ matrix.node-version }}
-      uses: actions/setup-node@v1
-      with:
-        node-version: ${{ matrix.node-version }}
-
-    - name: Install
-      run: |
-        npm install
-
-    - name: Test
-      run: |
-        npm run test:node8
-
   helpers-integration-test:
     name: Helpers integration test
     runs-on: ubuntu-latest

README.md

@@ -28,7 +28,7 @@ npm install @elastic/elasticsearch
 
 ### Node.js support
 
-NOTE: The minimum supported version of Node.js is `v8`.
+NOTE: The minimum supported version of Node.js is `v10`.
 
 The client versioning follows the Elastc Stack versioning, this means that
 major, minor, and patch releases are done following a precise schedule that

api/utils.js

@@ -31,10 +31,10 @@ function handleError (err, callback) {
 }
 
 function snakeCaseKeys (acceptedQuerystring, snakeCase, querystring) {
-  var target = {}
+  const target = {}
-  var keys = Object.keys(querystring)
+  const keys = Object.keys(querystring)
-  for (var i = 0, len = keys.length; i < len; i++) {
+  for (let i = 0, len = keys.length; i < len; i++) {
-    var key = keys[i]
+    const key = keys[i]
     target[snakeCase[key] || key] = querystring[key]
   }
   return target

docs/examples/asStream.asciidoc

@@ -57,7 +57,7 @@ async function run () {
   })
 
   // stream async iteration, available in Node.js ≥ 10
-  var payload = ''
+  let payload = ''
   body.setEncoding('utf8')
   for await (const chunk of body) {
     payload += chunk
@@ -65,7 +65,7 @@ async function run () {
   console.log(JSON.parse(payload))
 
   // classic stream callback style
-  var payload = ''
+  let payload = ''
   body.setEncoding('utf8')
   body.on('data', chunk => { payload += chunk })
   body.on('error', console.log)

docs/examples/scroll.asciidoc

@@ -124,7 +124,7 @@ const client = new Client({ node: 'http://localhost:9200' })
 
 // Scroll utility
 async function * scrollSearch (params) {
-  var response = await client.search(params)
+  let response = await client.search(params)
 
   while (true) {
     const sourceHits = response.body.hits.hits

docs/examples/sql.query.asciidoc

@@ -58,7 +58,7 @@ async function run () {
 
   const data = body.rows.map(row => {
     const obj = {}
-    for (var i = 0; i < row.length; i++) {
+    for (let i = 0; i < row.length; i++) {
       obj[body.columns[i].name] = row[i]
     }
     return obj

docs/installation.asciidoc

@@ -24,7 +24,7 @@ To learn more about the supported major versions, please refer to the
 [[nodejs-support]]
 === Node.js support
 
-NOTE: The minimum supported version of Node.js is `v8`.
+NOTE: The minimum supported version of Node.js is `v10`.
 
 The client versioning follows the {stack} versioning, this means that
 major, minor, and patch releases are done following a precise schedule that

index.js

@@ -27,8 +27,7 @@ const debug = require('debug')('elasticsearch')
 const Transport = require('./lib/Transport')
 const Connection = require('./lib/Connection')
 const { ConnectionPool, CloudConnectionPool } = require('./lib/pool')
-// Helpers works only in Node.js >= 10
+const Helpers = require('./lib/Helpers')
-const Helpers = nodeMajor < 10 ? /* istanbul ignore next */ null : require('./lib/Helpers')
 const Serializer = require('./lib/Serializer')
 const errors = require('./lib/errors')
 const { ConfigurationError } = errors
@@ -48,15 +47,6 @@ const kEventEmitter = Symbol('elasticsearchjs-event-emitter')
 
 const ESAPI = require('./api')
 
-/* istanbul ignore next */
-if (nodeMajor < 10) {
-  process.emitWarning('You are using a version of Node.js that is currently in EOL. ' +
-                      'The support for this version will be dropped in 7.12. ' +
-                      'Please refer to https://ela.st/nodejs-support for additional information.',
-  'DeprecationWarning'
-  )
-}
-
 /* istanbul ignore next */
 if (nodeMajor >= 10 && nodeMajor < 12) {
   process.emitWarning('You are using a version of Node.js that will reach EOL in April 2021. ' +
@@ -189,16 +179,13 @@ class Client extends ESAPI {
       context: options.context
     })
 
-    /* istanbul ignore else */
+    this.helpers = new Helpers({
-    if (Helpers !== null) {
+      client: this,
-      this.helpers = new Helpers({
+      maxRetries: options.maxRetries,
-        client: this,
+      metaHeader: options.enableMetaHeader
-        maxRetries: options.maxRetries,
+        ? `es=${clientVersion},js=${nodeVersion},t=${clientVersion},hc=${nodeVersion}`
-        metaHeader: options.enableMetaHeader
+        : null
-          ? `es=${clientVersion},js=${nodeVersion},t=${clientVersion},hc=${nodeVersion}`
+    })
-          : null
-      })
-    }
   }
 
   get emit () {
@@ -223,7 +210,7 @@ class Client extends ESAPI {
       opts = {}
     }
 
-    var [namespace, method] = name.split('.')
+    let [namespace, method] = name.split('.')
     if (method == null) {
       method = namespace
       namespace = null

lib/Connection.js

@@ -213,8 +213,8 @@ class Connection {
     }
 
     const paramsKeys = Object.keys(params)
-    for (var i = 0, len = paramsKeys.length; i < len; i++) {
+    for (let i = 0, len = paramsKeys.length; i < len; i++) {
-      var key = paramsKeys[i]
+      const key = paramsKeys[i]
       if (key === 'path') {
         request.pathname = resolve(request.pathname, params[key])
       } else if (key === 'querystring' && !!params[key] === true) {

lib/Serializer.js

@@ -27,8 +27,9 @@ const { SerializationError, DeserializationError } = require('./errors')
 class Serializer {
   serialize (object) {
     debug('Serializing', object)
+    let json
     try {
-      var json = JSON.stringify(object)
+      json = JSON.stringify(object)
     } catch (err) {
       throw new SerializationError(err.message, object)
     }
@@ -37,8 +38,9 @@ class Serializer {
 
   deserialize (json) {
     debug('Deserializing', json)
+    let object
     try {
-      var object = sjson.parse(json)
+      object = sjson.parse(json)
     } catch (err) {
       throw new DeserializationError(err.message, json)
     }
@@ -50,8 +52,8 @@ class Serializer {
     if (Array.isArray(array) === false) {
       throw new SerializationError('The argument provided is not an array')
     }
-    var ndjson = ''
+    let ndjson = ''
-    for (var i = 0, len = array.length; i < len; i++) {
+    for (let i = 0, len = array.length; i < len; i++) {
       if (typeof array[i] === 'string') {
         ndjson += array[i] + '\n'
       } else {
@@ -67,8 +69,8 @@ class Serializer {
     if (typeof object === 'string') return object
     // arrays should be serialized as comma separated list
     const keys = Object.keys(object)
-    for (var i = 0, len = keys.length; i < len; i++) {
+    for (let i = 0, len = keys.length; i < len; i++) {
-      var key = keys[i]
+      const key = keys[i]
       // elasticsearch will complain for keys without a value
       if (object[key] === undefined) {
         delete object[key]

lib/Transport.js

@@ -91,7 +91,7 @@ class Transport {
       callback = options
       options = {}
     }
-    var p = null
+    let p = null
 
     // promises support
     if (callback === undefined) {
@@ -147,9 +147,10 @@ class Transport {
     // the size of the stream, we risk to take too much memory.
     // Furthermore, copying everytime the stream is very a expensive operation.
     const maxRetries = isStream(params.body) || isStream(params.bulkBody)
-      ? 0 : (typeof options.maxRetries === 'number' ? options.maxRetries : this.maxRetries)
+      ? 0
+      : (typeof options.maxRetries === 'number' ? options.maxRetries : this.maxRetries)
     const compression = options.compression !== undefined ? options.compression : this.compression
-    var request = { abort: noop }
+    let request = { abort: noop }
     const transportReturn = {
       then (onFulfilled, onRejected) {
         return p.then(onFulfilled, onRejected)
@@ -525,7 +526,7 @@ function defaultNodeFilter (node) {
 }
 
 function roundRobinSelector () {
-  var current = -1
+  let current = -1
   return function _roundRobinSelector (connections) {
     if (++current >= connections.length) {
       current = 0
@@ -540,8 +541,8 @@ function randomSelector (connections) {
 }
 
 function generateRequestId () {
-  var maxInt = 2147483647
+  const maxInt = 2147483647
-  var nextReqId = 0
+  let nextReqId = 0
   return function genReqId (params, options) {
     return (nextReqId = (nextReqId + 1) & maxInt)
   }

lib/pool/BaseConnectionPool.js

@@ -128,7 +128,7 @@ class BaseConnectionPool {
    */
   empty (callback) {
     debug('Emptying the connection pool')
-    var openConnections = this.size
+    let openConnections = this.size
     this.connections.forEach(connection => {
       connection.close(() => {
         if (--openConnections === 0) {
@@ -201,7 +201,7 @@ class BaseConnectionPool {
     const ids = Object.keys(nodes)
     const hosts = []
 
-    for (var i = 0, len = ids.length; i < len; i++) {
+    for (let i = 0, len = ids.length; i < len; i++) {
       const node = nodes[ids[i]]
       // If there is no protocol in
       // the `publish_address` new URL will throw
@@ -210,7 +210,7 @@ class BaseConnectionPool {
       //   - hostname/ip:port
       // if we encounter the second case, we should
       // use the hostname instead of the ip
-      var address = node.http.publish_address
+      let address = node.http.publish_address
       const parts = address.split('/')
       // the url is in the form of hostname/ip:port
       if (parts.length > 1) {

lib/pool/ConnectionPool.js

@@ -80,7 +80,7 @@ class ConnectionPool extends BaseConnectionPool {
       // list a node that no longer exist. The following check verify
       // that the connection is still part of the pool before
       // marking it as dead.
-      for (var i = 0; i < this.size; i++) {
+      for (let i = 0; i < this.size; i++) {
         if (this.connections[i].id === id) {
           this.dead.push(id)
           break
@@ -138,7 +138,7 @@ class ConnectionPool extends BaseConnectionPool {
         path: '/',
         timeout: this.pingTimeout
       }, (err, response) => {
-        var isAlive = true
+        let isAlive = true
         const statusCode = response !== null ? response.statusCode : 0
         if (err != null ||
            (statusCode === 502 || statusCode === 503 || statusCode === 504)) {
@@ -170,8 +170,7 @@ class ConnectionPool extends BaseConnectionPool {
         isAlive: true,
         connection
       })
-      // eslint-disable-next-line standard/no-callback-literal
+      callback(true, connection) // eslint-disable-line
-      callback(true, connection)
     }
   }
 
@@ -199,7 +198,7 @@ class ConnectionPool extends BaseConnectionPool {
 
     // TODO: can we cache this?
     const connections = []
-    for (var i = 0; i < this.size; i++) {
+    for (let i = 0; i < this.size; i++) {
       const connection = this.connections[i]
       if (noAliveConnections || connection.status === Connection.statuses.ALIVE) {
         if (filter(connection) === true) {

package.json

@@ -25,7 +25,6 @@
   ],
   "scripts": {
     "test": "npm run lint && tap test/{unit,acceptance}/{*,**/*}.test.js && npm run test:types",
-    "test:node8": "npm run lint && tap test/{unit,acceptance}/*.test.js",
     "test:unit": "tap test/unit/{*,**/*}.test.js",
     "test:acceptance": "tap test/acceptance/*.test.js",
     "test:integration": "node test/integration/index.js",
@@ -49,37 +48,37 @@
   },
   "devDependencies": {
     "@sinonjs/fake-timers": "github:sinonjs/fake-timers#0bfffc1",
-    "@types/node": "^12.6.2",
+    "@types/node": "^14.14.28",
     "convert-hrtime": "^3.0.0",
     "dedent": "^0.7.0",
-    "deepmerge": "^4.0.0",
+    "deepmerge": "^4.2.2",
     "dezalgo": "^1.0.3",
-    "fast-deep-equal": "^3.1.1",
+    "fast-deep-equal": "^3.1.3",
-    "into-stream": "^5.1.1",
+    "into-stream": "^6.0.0",
-    "js-yaml": "^3.13.1",
+    "js-yaml": "^4.0.0",
     "license-checker": "^25.0.1",
-    "minimist": "^1.2.0",
+    "minimist": "^1.2.5",
-    "ora": "^3.4.0",
+    "ora": "^5.3.0",
     "pretty-hrtime": "^1.0.3",
     "proxy": "^1.0.2",
-    "rimraf": "^2.6.3",
+    "rimraf": "^3.0.2",
-    "semver": "^6.0.0",
+    "semver": "^7.3.4",
-    "simple-git": "^1.110.0",
+    "simple-git": "^2.35.0",
-    "simple-statistics": "^7.0.2",
+    "simple-statistics": "^7.4.1",
-    "split2": "^3.1.1",
+    "split2": "^3.2.2",
-    "standard": "^13.0.2",
+    "standard": "^16.0.3",
     "stoppable": "^1.1.0",
-    "tap": "^14.4.1",
+    "tap": "^14.11.0",
-    "tsd": "^0.13.1",
+    "tsd": "^0.14.0",
-    "workq": "^2.1.0",
+    "workq": "^3.0.0",
-    "xmlbuilder2": "^2.1.2"
+    "xmlbuilder2": "^2.4.0"
   },
   "dependencies": {
-    "debug": "^4.1.1",
+    "debug": "^4.3.1",
     "hpagent": "^0.1.1",
-    "ms": "^2.1.1",
+    "ms": "^2.1.3",
     "pump": "^3.0.0",
-    "secure-json-parse": "^2.1.0"
+    "secure-json-parse": "^2.3.1"
   },
   "license": "Apache-2.0",
   "repository": {
@@ -90,11 +89,16 @@
     "url": "https://github.com/elastic/elasticsearch-js/issues"
   },
   "engines": {
-    "node": ">=8"
+    "node": ">=10"
   },
   "tsd": {
     "directory": "test/types"
   },
+  "standard": {
+    "ignore": [
+      "/api"
+    ]
+  },
   "tap": {
     "esm": false,
     "ts": false,

scripts/generate-docs-examples.js

@@ -126,14 +126,14 @@ function generate () {
 }
 
 function generateAsciidoc (source) {
-  var asciidoc = '// This file is autogenerated, DO NOT EDIT\n'
+  let asciidoc = '// This file is autogenerated, DO NOT EDIT\n'
   asciidoc += '// Use `node scripts/generate-docs-examples.js` to generate the docs examples\n\n'
-  var code = 'async function run (client) {\n// START\n'
+  let code = 'async function run (client) {\n// START\n'
 
-  for (var i = 0; i < source.length; i++) {
+  for (let i = 0; i < source.length; i++) {
     const { api, query, params, body } = source[i]
     const apiArguments = Object.assign({}, params, query, body ? { body } : body)
-    var serializedApiArguments = Object.keys(apiArguments).length > 0
+    const serializedApiArguments = Object.keys(apiArguments).length > 0
       ? JSON.stringify(apiArguments, null, 2)
       : ''
     code += `const response${getResponsePostfix(i)} = await client.${api.replace(/_([a-z])/g, g => g[1].toUpperCase())}(${serializedApiArguments})

scripts/utils/clone-es.js

@@ -42,8 +42,8 @@ function cloneAndCheckout (opts, callback) {
    * @param {function} callback
    */
   function withTag (tag, callback) {
-    var fresh = false
+    let fresh = false
-    var retry = 0
+    let retry = 0
 
     if (!pathExist(esFolder)) {
       if (!createFolder(esFolder)) {

scripts/utils/generateApis.js

@@ -206,7 +206,7 @@ function generateSingleApi (version, spec, common) {
   // get the required parts from the url
   // if the url has at least one static path,
   // then there are not required parts of the url
-  var allParts = []
+  let allParts = []
   for (const path of paths) {
     if (path.parts) {
       allParts.push(Object.keys(path.parts))
@@ -250,10 +250,10 @@ function generateSingleApi (version, spec, common) {
 
     ${genUrlValidation(paths, api)}
 
-    var { ${genQueryBlacklist(false)}, ...querystring } = params
+    let { ${genQueryBlacklist(false)}, ...querystring } = params
     querystring = snakeCaseKeys(acceptedQuerystring, snakeCase, querystring)
 
-    var path = ''
+    let path = ''
     ${buildPath(api)}
 
     // build request object
@@ -289,7 +289,7 @@ function generateSingleApi (version, spec, common) {
     return code.join('\n        ')
 
     function _genRequiredCheck (param) {
-      var camelCased = param[0] === '_'
+      const camelCased = param[0] === '_'
         ? '_' + param.slice(1).replace(/_([a-z])/g, k => k[1].toUpperCase())
         : param.replace(/_([a-z])/g, k => k[1].toUpperCase())
 
@@ -386,7 +386,7 @@ function generateSingleApi (version, spec, common) {
       return path.length > 0 ? ('\'/\' + ' + path) : '\'/\''
     }
 
-    var hasStaticPath = false
+    let hasStaticPath = false
     const sortedPaths = paths
       // some legacy API have mutliple statis paths
       // this filter removes them
@@ -401,8 +401,8 @@ function generateSingleApi (version, spec, common) {
       // sort by number of parameters (desc)
       .sort((a, b) => Object.keys(b.parts || {}).length - Object.keys(a.parts || {}).length)
 
-    var code = ''
+    let code = ''
-    for (var i = 0; i < sortedPaths.length; i++) {
+    for (let i = 0; i < sortedPaths.length; i++) {
       const { path, methods } = sortedPaths[i]
       if (sortedPaths.length === 1) {
         code += `if (method == null) method = ${generatePickMethod(methods)}
@@ -454,9 +454,9 @@ function genBody (api, methods, body) {
     return 'bulkBody: body,'
   }
   if (body === null && bodyMethod) {
-    return `body: '',`
+    return 'body: \'\','
   } else if (bodyMethod) {
-    return `body: body || '',`
+    return 'body: body || \'\','
   } else {
     return 'body: null,'
   }
@@ -490,13 +490,13 @@ function genUrlValidation (paths, api) {
     .map(s => s.slice(1, -1))
     .reverse()
 
-  var code = ''
+  let code = ''
 
   const len = chunks.length
   chunks.forEach((chunk, index) => {
     if (index === len - 1) return
-    var params = []
+    const params = []
-    var camelCased = chunk[0] === '_'
+    let camelCased = chunk[0] === '_'
       ? '_' + chunk.slice(1).replace(/_([a-z])/g, k => k[1].toUpperCase())
       : chunk.replace(/_([a-z])/g, k => k[1].toUpperCase())
 
@@ -505,7 +505,7 @@ function genUrlValidation (paths, api) {
     } else {
       code += `${index ? '} else ' : ''}if ((params['${chunk}'] != null || params['${camelCased}'] != null) && (`
     }
-    for (var i = index + 1; i < len; i++) {
+    for (let i = index + 1; i < len; i++) {
       params.push(chunks[i])
       // url parts can be declared in camelCase fashion
       camelCased = chunks[i][0] === '_'
@@ -541,7 +541,7 @@ function generateDocumentation ({ documentation }, op) {
 
   if (documentation == null) return ''
 
-  var doc = '/**\n'
+  let doc = '/**\n'
   doc += `     * Perform a ${op} request\n`
   if (documentation.description) {
     doc += `     * ${documentation.description.replace(/\u00A0/g, ' ')}\n`

scripts/utils/generateDocs.js

@@ -28,7 +28,7 @@ const codeExamples = readdirSync(join(__dirname, '..', '..', 'docs', 'examples')
   .filter(api => api !== 'index')
 
 function generateDocs (common, spec) {
-  var doc = dedent`
+  let doc = dedent`
   [[api-reference]]
 
   ////////
@@ -110,7 +110,7 @@ function generateDocs (common, spec) {
 }
 
 function commonParameters (spec) {
-  var doc = dedent`
+  let doc = dedent`
   [discrete]
   === Common parameters
   Parameters that are accepted by all API endpoints.
@@ -196,7 +196,7 @@ function generateApiDoc (spec) {
 
   const codeParameters = params
     .reduce((acc, val) => {
-      var code = `${val.name}: ${val.type},`
+      const code = `${val.name}: ${val.type},`
       acc += acc === ''
         ? code
         : '\n    ' + code
@@ -210,7 +210,7 @@ function generateApiDoc (spec) {
     ? ''
     : `*Stability:* ${spec[name].stability}`
 
-  var doc = dedent`
+  let doc = dedent`
   [discrete]
   === ${camelify(name)}
   ${stability}
@@ -239,7 +239,7 @@ function generateApiDoc (spec) {
         acc += ` +\n_Default:_ ${'`' + val.default + '`'}`
       }
       if (val.deprecated) {
-        acc += ` +\n\nWARNING: This parameter has been deprecated.`
+        acc += ' +\n\nWARNING: This parameter has been deprecated.'
       }
       return acc + '\n\n'
     }, '')

scripts/utils/generateMain.js

@@ -235,44 +235,44 @@ function buildMethodDefinition (opts, api, name, hasBody, isHead) {
   if (opts.kibana) {
     if (hasBody) {
       return [
-        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: `TransportRequestPromise<ApiResponse<TResponse, TContext>>` }
+        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: 'TransportRequestPromise<ApiResponse<TResponse, TContext>>' }
       ]
     } else {
       return [
-        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: `TransportRequestPromise<ApiResponse<TResponse, TContext>>` }
+        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: 'TransportRequestPromise<ApiResponse<TResponse, TContext>>' }
       ]
     }
   }
 
   if (hasBody) {
     let methods = [
-      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: `TransportRequestPromise<ApiResponse<TResponse, TContext>>` },
+      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: 'TransportRequestPromise<ApiResponse<TResponse, TContext>>' },
-      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+      { key: `${api}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' }
     ]
     if (isSnakeCased(api)) {
       methods = methods.concat([
-        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: `TransportRequestPromise<ApiResponse<TResponse, TContext>>` },
+        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params?: RequestParams.${Name}<TRequestBody>, options?: TransportRequestOptions)`, val: 'TransportRequestPromise<ApiResponse<TResponse, TContext>>' },
-        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+        { key: `${camelify(api)}<TResponse = ${responseType}, TRequestBody extends ${bodyType} = ${defaultBodyType}, TContext = Context>(params: RequestParams.${Name}<TRequestBody>, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' }
       ])
     }
     return methods
   } else {
     let methods = [
-      { key: `${api}<TResponse = ${responseType}, TContext = Context>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: `TransportRequestPromise<ApiResponse<TResponse, TContext>>` },
+      { key: `${api}<TResponse = ${responseType}, TContext = Context>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: 'TransportRequestPromise<ApiResponse<TResponse, TContext>>' },
-      { key: `${api}<TResponse = ${responseType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TResponse = ${responseType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-      { key: `${api}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+      { key: `${api}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-      { key: `${api}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+      { key: `${api}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' }
     ]
     if (isSnakeCased(api)) {
       methods = methods.concat([
-        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: `TransportRequestPromise<ApiResponse<TResponse, TContext>>` },
+        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params?: RequestParams.${Name}, options?: TransportRequestOptions)`, val: 'TransportRequestPromise<ApiResponse<TResponse, TContext>>' },
-        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` },
+        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' },
-        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: `TransportRequestCallback` }
+        { key: `${camelify(api)}<TResponse = ${responseType}, TContext = Context>(params: RequestParams.${Name}, options: TransportRequestOptions, callback: callbackFn<TResponse, TContext>)`, val: 'TransportRequestCallback' }
       ])
     }
     return methods

scripts/utils/generateRequestTypes.js

@@ -33,7 +33,7 @@ const ndjsonApiKey = ndjsonApi
 
 function generate (version, api) {
   const release = semver.valid(version) ? semver.major(version) : version
-  var types = `/*
+  let types = `/*
  * Licensed to Elasticsearch B.V. under one or more contributor
  * license agreements. See the NOTICE file distributed with
  * this work for additional information regarding copyright
@@ -79,8 +79,8 @@ export interface Generic {
     // get the required parts from the url
     // if the url has at least one static path,
     // then there are not required parts of the url
-    var allParts = []
+    let allParts = []
-    var requiredParts = []
+    let requiredParts = []
     for (const path of paths) {
       if (path.parts) {
         allParts.push(Object.keys(path.parts))
@@ -146,7 +146,7 @@ export interface ${toPascalCase(name)}${body ? `<T = ${bodyGeneric}>` : ''} exte
       case 'time':
       case 'timeout':
         return 'string'
-      case 'enum':
+      case 'enum': {
         // the following code changes 'true' | 'false' to boolean
         let foundTrue = false
         let foundFalse = false
@@ -172,6 +172,7 @@ export interface ${toPascalCase(name)}${body ? `<T = ${bodyGeneric}>` : ''} exte
           options.push('boolean')
         }
         return options.join(' | ')
+      }
       case 'int':
       case 'double':
       case 'long':

test/acceptance/observability.test.js

@@ -16,7 +16,7 @@ test('Request id', t => {
     const genReqId = generateRequestId()
     t.type(genReqId, 'function')
 
-    for (var i = 1; i <= 10; i++) {
+    for (let i = 1; i <= 10; i++) {
       t.strictEqual(genReqId(), i)
     }
 

test/acceptance/resurrect.test.js

@@ -95,7 +95,7 @@ test('Resurrect a node and handle 502/3/4 status code', t => {
   const clock = FakeTimers.install({ toFake: ['Date'] })
   const q = workq()
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     res.statusCode = count++ < 2 ? 502 : 200
     res.setHeader('content-type', 'application/json')
@@ -114,7 +114,7 @@ test('Resurrect a node and handle 502/3/4 status code', t => {
       maxRetries: 0
     })
 
-    var idCount = 2
+    let idCount = 2
     client.on(events.RESURRECT, (err, meta) => {
       t.error(err)
       t.strictEqual(meta.strategy, 'ping')

test/acceptance/sniff.test.js

@@ -59,7 +59,7 @@ test('Should update the connection pool', t => {
       t.strictEqual(hosts.length, 4)
 
       const ids = Object.keys(nodes)
-      for (var i = 0; i < hosts.length; i++) {
+      for (let i = 0; i < hosts.length; i++) {
         const id = ids[i]
         // the first node will be an update of the existing one
         if (id === 'node0') {
@@ -118,7 +118,7 @@ test('Should handle hostnames in publish_address', t => {
       t.error(err)
       t.strictEqual(hosts.length, 4)
 
-      for (var i = 0; i < hosts.length; i++) {
+      for (let i = 0; i < hosts.length; i++) {
         // the first node will be an update of the existing one
         t.strictEqual(hosts[i].url.hostname, 'localhost')
       }

test/benchmarks/macro/complex.bench.js

@@ -16,7 +16,7 @@ const { bench, beforeEach, afterEach } = require('../suite')({
   }
 })
 
-var stackoverflow = []
+let stackoverflow = []
 const stackoverflowPath = join(
   __dirname,
   'fixtures',
@@ -53,7 +53,7 @@ bench('Bulk index documents', {
   action: 'bulk'
 }, async b => {
   b.start()
-  for (var i = 0; i < stackoverflow.length; i++) {
+  for (let i = 0; i < stackoverflow.length; i++) {
     await b.client.bulk({ body: stackoverflow[i] })
   }
   b.end()
@@ -67,7 +67,7 @@ bench('Complex search request', {
   action: 'search'
 }, async b => {
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.search({
       index: INDEX,
       body: {
@@ -81,8 +81,8 @@ bench('Complex search request', {
 })
 
 function readSOfile () {
-  var i = 0
+  let i = 0
-  var stackoverflow = []
+  const stackoverflow = []
   return new Promise((resolve, reject) => {
     createReadStream(stackoverflowPath)
       .pipe(split(JSON.parse))

test/benchmarks/macro/simple.bench.js

@@ -44,7 +44,7 @@ bench('Ping', {
   action: 'ping'
 }, async b => {
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.ping()
   }
   b.end()
@@ -57,7 +57,7 @@ bench('Create index', {
   action: 'indices.create'
 }, async b => {
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.indices.create({ index: `test-create-${i}` })
   }
   b.end()
@@ -75,7 +75,7 @@ bench('Index small document', {
   await b.client.indices.create({ index })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.create({
       index,
       type: '_doc',
@@ -98,7 +98,7 @@ bench('Index large document', {
   await b.client.indices.create({ index })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.create({
       index,
       type: '_doc',
@@ -128,7 +128,7 @@ bench('Get small document', {
   })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.get({
       index,
       type: '_doc',
@@ -157,7 +157,7 @@ bench('Get large document', {
   })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.get({
       index,
       type: '_doc',
@@ -187,7 +187,7 @@ bench('Search small document', {
   })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.search({
       index,
       type: '_doc',
@@ -221,7 +221,7 @@ bench('Search large document', {
   })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.search({
       index,
       type: '_doc',
@@ -255,7 +255,7 @@ bench('Update small document', {
   })
 
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await b.client.update({
       index,
       type: '_doc',

test/benchmarks/micro/basic.bench.js

@@ -12,7 +12,7 @@ const { connection } = require('../../utils')
 
 bench('Initialization', { warmup: 5, measure: 10, iterations: 1000 }, async b => {
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     const client = new Client({ // eslint-disable-line
       node: 'http://localhost:9200'
     })
@@ -56,7 +56,7 @@ bench('Basic get', { warmup: 5, measure: 10, iterations: 1000 }, async b => {
     q: 'foo:bar'
   })
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await client.search({
       index: 'test',
       type: 'doc',
@@ -83,7 +83,7 @@ bench('Basic post', { warmup: 5, measure: 10, iterations: 1000 }, async b => {
     }
   })
   b.start()
-  for (var i = 0; i < b.iterations; i++) {
+  for (let i = 0; i < b.iterations; i++) {
     await client.search({
       index: 'test',
       type: 'doc',

test/benchmarks/suite.js

@@ -15,10 +15,10 @@ function buildBenchmark (options = {}) {
   const q = workq()
   const stats = {}
   const reports = []
-  var beforeEach = null
+  let beforeEach = null
-  var afterEach = null
+  let afterEach = null
-  var setup = null
+  let setup = null
-  var teardown = null
+  let teardown = null
 
   function setBeforeEach (fn) {
     beforeEach = fn
@@ -54,7 +54,7 @@ function buildBenchmark (options = {}) {
     }
 
     stats[title] = []
-    var { measure, warmup } = opts
+    let { measure, warmup } = opts
     const b = new B({ iterations: opts.iterations })
 
     q.add(runSetup)
@@ -225,7 +225,7 @@ function buildBenchmark (options = {}) {
       }
     })
 
-    for (var i = 0; i < results.length; i++) {
+    for (let i = 0; i < results.length; i++) {
       await client.index({
         index: 'benchmarking_results',
         type: '_doc',

test/integration/helpers/scroll.test.js

@@ -65,7 +65,7 @@ test('search helper', async t => {
     }
   })
 
-  var count = 0
+  let count = 0
   for await (const search of scrollSearch) {
     count += 1
     for (const doc of search.documents) {
@@ -87,7 +87,7 @@ test('clear a scroll search', async t => {
     }
   })
 
-  var count = 0
+  let count = 0
   for await (const search of scrollSearch) {
     count += 1
     if (count === 2) {
@@ -109,7 +109,7 @@ test('scroll documents', async t => {
     }
   })
 
-  var count = 0
+  let count = 0
   for await (const doc of scrollSearch) {
     count += 1
     t.true(doc.title.toLowerCase().includes('javascript'))

test/integration/index.js

@@ -179,8 +179,8 @@ async function start ({ client, isXPack }) {
     // to provide a better test log output
     .reduce((arr, file) => {
       const path = file.slice(file.indexOf('/rest-api-spec/test'), file.lastIndexOf('/'))
-      var inserted = false
+      let inserted = false
-      for (var i = 0; i < arr.length; i++) {
+      for (let i = 0; i < arr.length; i++) {
         if (arr[i][0].includes(path)) {
           inserted = true
           arr[i].push(file)
@@ -223,8 +223,8 @@ async function start ({ client, isXPack }) {
         .filter(Boolean)
 
       // get setup and teardown if present
-      var setupTest = null
+      let setupTest = null
-      var teardownTest = null
+      let teardownTest = null
       for (const test of tests) {
         if (test.setup) setupTest = test.setup
         if (test.teardown) teardownTest = test.teardown
@@ -299,14 +299,15 @@ function log (text) {
 }
 
 function now () {
-  var ts = process.hrtime()
+  const ts = process.hrtime()
   return (ts[0] * 1e3) + (ts[1] / 1e6)
 }
 
 function parse (data) {
   const schema = yaml.Schema.create(yaml.CORE_SCHEMA, [])
+  let doc
   try {
-    var doc = yaml.safeLoad(data, { schema })
+    doc = yaml.safeLoad(data, { schema })
   } catch (err) {
     console.error(err)
     return
@@ -329,8 +330,8 @@ function withSHA (sha) {
   })
 
   function _withSHA (callback) {
-    var fresh = false
+    let fresh = false
-    var retry = 0
+    let retry = 0
 
     if (!pathExist(esFolder)) {
       if (!createFolder(esFolder)) {
@@ -427,10 +428,10 @@ if (require.main === module) {
 }
 
 const shouldSkip = (isXPack, file, name) => {
-  var list = Object.keys(freeSkips)
+  let list = Object.keys(freeSkips)
-  for (var i = 0; i < list.length; i++) {
+  for (let i = 0; i < list.length; i++) {
     const freeTest = freeSkips[list[i]]
-    for (var j = 0; j < freeTest.length; j++) {
+    for (let j = 0; j < freeTest.length; j++) {
       if (file.endsWith(list[i]) && (name === freeTest[j] || freeTest[j] === '*')) {
         const testName = file.slice(file.indexOf(`${sep}elasticsearch${sep}`)) + ' / ' + name
         log(`Skipping test ${testName} because is blacklisted in the free test`)
@@ -441,9 +442,9 @@ const shouldSkip = (isXPack, file, name) => {
 
   if (file.includes('x-pack') || isXPack) {
     list = Object.keys(platinumBlackList)
-    for (i = 0; i < list.length; i++) {
+    for (let i = 0; i < list.length; i++) {
       const platTest = platinumBlackList[list[i]]
-      for (j = 0; j < platTest.length; j++) {
+      for (let j = 0; j < platTest.length; j++) {
         if (file.endsWith(list[i]) && (name === platTest[j] || platTest[j] === '*')) {
           const testName = file.slice(file.indexOf(`${sep}elasticsearch${sep}`)) + ' / ' + name
           log(`Skipping test ${testName} because is blacklisted in the platinum test`)

test/integration/test-runner.js

@@ -320,7 +320,7 @@ function build (opts = {}) {
    */
   function set (key, name) {
     if (key.includes('_arbitrary_key_')) {
-      var currentVisit = null
+      let currentVisit = null
       for (const path of key.split('.')) {
         if (path === '_arbitrary_key_') {
           const keys = Object.keys(currentVisit)
@@ -361,8 +361,9 @@ function build (opts = {}) {
    */
   async function doAction (action, stats) {
     const cmd = parseDo(action)
+    let api
     try {
-      var api = delve(client, cmd.method).bind(client)
+      api = delve(client, cmd.method).bind(client)
     } catch (err) {
       console.error(`\nError: Cannot find the method '${cmd.method}' in the client.\n`)
       process.exit(1)
@@ -373,8 +374,8 @@ function build (opts = {}) {
     if (cmd.params.ignore) delete cmd.params.ignore
 
     const [err, result] = await to(api(cmd.params, options))
-    var warnings = result ? result.warnings : null
+    let warnings = result ? result.warnings : null
-    var body = result ? result.body : null
+    const body = result ? result.body : null
 
     if (action.warnings && warnings === null) {
       assert.fail('We should get a warning header', action.warnings)
@@ -719,7 +720,7 @@ function parseDo (action) {
 
     for (const key in obj) {
       const val = obj[key]
-      var newKey = key
+      let newKey = key
       if (!~doNotCamelify.indexOf(key)) {
         // if the key starts with `_` we should not camelify the first occurence
         // eg: _source_include => _sourceInclude
@@ -776,7 +777,7 @@ function parseDoError (err, spec) {
 
 function getSkip (arr) {
   if (!Array.isArray(arr)) return null
-  for (var i = 0; i < arr.length; i++) {
+  for (let i = 0; i < arr.length; i++) {
     if (arr[i].skip) return arr[i].skip
   }
   return null
@@ -822,7 +823,7 @@ function logSkip (action) {
  * @returns {boolean}
  */
 function shouldSkip (esVersion, action) {
-  var shouldSkip = false
+  let shouldSkip = false
   // skip based on the version
   if (action.version) {
     if (action.version.trim() === 'all') return true

test/unit/base-connection-pool.test.js

@@ -63,7 +63,7 @@ test('API', t => {
   t.test('markDead', t => {
     const pool = new BaseConnectionPool({ Connection, sniffEnabled: true })
     const href = 'http://localhost:9200/'
-    var connection = pool.addConnection(href)
+    let connection = pool.addConnection(href)
     t.same(pool.markDead(connection), pool)
     connection = pool.connections.find(c => c.id === href)
     t.strictEqual(connection.status, Connection.statuses.ALIVE)
@@ -73,7 +73,7 @@ test('API', t => {
   t.test('markAlive', t => {
     const pool = new BaseConnectionPool({ Connection, sniffEnabled: true })
     const href = 'http://localhost:9200/'
-    var connection = pool.addConnection(href)
+    let connection = pool.addConnection(href)
     t.same(pool.markAlive(connection), pool)
     connection = pool.connections.find(c => c.id === href)
     t.strictEqual(connection.status, Connection.statuses.ALIVE)
@@ -96,7 +96,7 @@ test('API', t => {
   t.test('removeConnection', t => {
     const pool = new BaseConnectionPool({ Connection })
     const href = 'http://localhost:9200/'
-    var connection = pool.addConnection(href)
+    const connection = pool.addConnection(href)
     pool.removeConnection(connection)
     t.strictEqual(pool.size, 0)
     t.end()

test/unit/child.test.js

@@ -29,7 +29,7 @@ const {
 test('Should create a child client (headers check)', t => {
   t.plan(4)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     if (count++ === 0) {
       t.match(req.headers, { 'x-foo': 'bar' })
@@ -216,12 +216,12 @@ test('Should create a child client (generateRequestId check)', t => {
   t.plan(6)
 
   function generateRequestId1 () {
-    var id = 0
+    let id = 0
     return () => `trace-1-${id++}`
   }
 
   function generateRequestId2 () {
-    var id = 0
+    let id = 0
     return () => `trace-2-${id++}`
   }
 
@@ -235,7 +235,7 @@ test('Should create a child client (generateRequestId check)', t => {
     generateRequestId: generateRequestId2()
   })
 
-  var count = 0
+  let count = 0
   client.on('request', (err, { meta }) => {
     t.error(err)
     t.strictEqual(
@@ -266,7 +266,7 @@ test('Should create a child client (name check)', t => {
   t.strictEqual(client.name, 'parent')
   t.strictEqual(child.name, 'child')
 
-  var count = 0
+  let count = 0
   client.on('request', (err, { meta }) => {
     t.error(err)
     t.strictEqual(
@@ -284,7 +284,7 @@ test('Should create a child client (name check)', t => {
 test('Should create a child client (auth check)', t => {
   t.plan(4)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     if (count++ === 0) {
       t.match(req.headers, { authorization: 'Basic Zm9vOmJhcg==' })

test/unit/client.test.js

@@ -287,7 +287,7 @@ test('Authentication', t => {
     t.test('Custom basic authentication per request', t => {
       t.plan(6)
 
-      var first = true
+      let first = true
       function handler (req, res) {
         t.match(req.headers, {
           authorization: first ? 'hello' : 'Basic Zm9vOmJhcg=='
@@ -322,7 +322,7 @@ test('Authentication', t => {
     t.test('Override default basic authentication per request', t => {
       t.plan(6)
 
-      var first = true
+      let first = true
       function handler (req, res) {
         t.match(req.headers, {
           authorization: first ? 'hello' : 'Basic Zm9vOmJhcg=='
@@ -419,7 +419,7 @@ test('Authentication', t => {
     t.test('Custom ApiKey authentication per request', t => {
       t.plan(6)
 
-      var first = true
+      let first = true
       function handler (req, res) {
         t.match(req.headers, {
           authorization: first ? 'ApiKey Zm9vOmJhcg==' : 'Basic Zm9vOmJhcg=='
@@ -454,7 +454,7 @@ test('Authentication', t => {
     t.test('Override default ApiKey authentication per request', t => {
       t.plan(6)
 
-      var first = true
+      let first = true
       function handler (req, res) {
         t.match(req.headers, {
           authorization: first ? 'hello' : 'ApiKey Zm9vOmJhcg=='
@@ -1091,8 +1091,8 @@ test('Correctly handles the same header cased differently', t => {
   t.plan(4)
 
   function handler (req, res) {
-    t.strictEqual(req.headers['authorization'], 'Basic foobar')
+    t.strictEqual(req.headers.authorization, 'Basic foobar')
-    t.strictEqual(req.headers['foo'], 'baz')
+    t.strictEqual(req.headers.foo, 'baz')
     res.setHeader('Content-Type', 'application/json;utf=8')
     res.end(JSON.stringify({ hello: 'world' }))
   }

test/unit/connection-pool.test.js

@@ -66,7 +66,7 @@ test('API', t => {
   t.test('markDead', t => {
     const pool = new ConnectionPool({ Connection, sniffEnabled: true })
     const href = 'http://localhost:9200/'
-    var connection = pool.addConnection(href)
+    let connection = pool.addConnection(href)
     pool.markDead(connection)
     connection = pool.connections.find(c => c.id === href)
     t.strictEqual(connection.deadCount, 1)
@@ -100,7 +100,7 @@ test('API', t => {
   t.test('markAlive', t => {
     const pool = new ConnectionPool({ Connection, sniffEnabled: true })
     const href = 'http://localhost:9200/'
-    var connection = pool.addConnection(href)
+    let connection = pool.addConnection(href)
     pool.markDead(connection)
     pool.markAlive(connection)
     connection = pool.connections.find(c => c.id === href)
@@ -121,7 +121,7 @@ test('API', t => {
           sniffEnabled: true
         })
         const href = 'http://localhost:9200/'
-        var connection = pool.addConnection(href)
+        const connection = pool.addConnection(href)
         pool.markDead(connection)
         const opts = {
           now: Date.now() + 1000 * 60 * 3,
@@ -147,7 +147,7 @@ test('API', t => {
           sniffEnabled: true
         })
         const href = 'http://localhost:9200/'
-        var connection = pool.addConnection(href)
+        const connection = pool.addConnection(href)
         pool.markDead(connection)
         const opts = {
           now: Date.now() + 1000 * 60 * 3,
@@ -175,7 +175,7 @@ test('API', t => {
         sniffEnabled: true
       })
       const href = 'http://localhost:9200/'
-      var connection = pool.addConnection(href)
+      const connection = pool.addConnection(href)
       pool.markDead(connection)
       const opts = {
         now: Date.now() + 1000 * 60 * 3,
@@ -200,7 +200,7 @@ test('API', t => {
         sniffEnabled: true
       })
       const href = 'http://localhost:9200/'
-      var connection = pool.addConnection(href)
+      const connection = pool.addConnection(href)
       pool.markDead(connection)
       const opts = {
         now: Date.now() + 1000 * 60 * 3,
@@ -292,7 +292,7 @@ test('API', t => {
   t.test('removeConnection', t => {
     const pool = new ConnectionPool({ Connection })
     const href = 'http://localhost:9200/'
-    var connection = pool.addConnection(href)
+    const connection = pool.addConnection(href)
     t.ok(pool.getConnection() instanceof Connection)
     pool.removeConnection(connection)
     t.strictEqual(pool.getConnection(), null)

test/unit/connection.test.js

@@ -58,7 +58,7 @@ test('Basic (http)', t => {
         connection: 'keep-alive'
       })
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -98,7 +98,7 @@ test('Basic (https)', t => {
         connection: 'keep-alive'
       })
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -139,7 +139,7 @@ test('Basic (https with ssl agent)', t => {
         connection: 'keep-alive'
       })
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -193,7 +193,7 @@ test('Custom http agent', t => {
         connection: 'keep-alive'
       })
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -317,7 +317,7 @@ test('Body request', t => {
   t.plan(2)
 
   function handler (req, res) {
-    var payload = ''
+    let payload = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { payload += chunk })
     req.on('error', err => t.fail(err))
@@ -346,7 +346,7 @@ test('Send body as buffer', t => {
   t.plan(2)
 
   function handler (req, res) {
-    var payload = ''
+    let payload = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { payload += chunk })
     req.on('error', err => t.fail(err))
@@ -375,7 +375,7 @@ test('Send body as stream', t => {
   t.plan(2)
 
   function handler (req, res) {
-    var payload = ''
+    let payload = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { payload += chunk })
     req.on('error', err => t.fail(err))
@@ -424,7 +424,7 @@ test('Should not close a connection if there are open requests', t => {
       t.error(err)
       t.strictEqual(connection._openRequests, 0)
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -461,7 +461,7 @@ test('Should not close a connection if there are open requests (with agent disab
       t.error(err)
       t.strictEqual(connection._openRequests, 0)
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -571,7 +571,7 @@ test('asStream set to true', t => {
     }, (err, res) => {
       t.error(err)
 
-      var payload = ''
+      let payload = ''
       res.setEncoding('utf8')
       res.on('data', chunk => { payload += chunk })
       res.on('error', err => t.fail(err))
@@ -887,7 +887,7 @@ test('Should correctly resolve request pathname', t => {
   t.plan(1)
 
   const connection = new Connection({
-    url: new URL(`http://localhost:80/test`)
+    url: new URL('http://localhost:80/test')
   })
 
   t.strictEqual(

test/unit/events.test.js

@@ -20,7 +20,6 @@
 'use strict'
 
 const { test } = require('tap')
-const semver = require('semver')
 const { Client, events } = require('../../index')
 const { TimeoutError } = require('../../lib/errors')
 const {
@@ -127,7 +126,7 @@ test('Should emit a request event once when a request is performed', t => {
   })
 })
 
-test('Remove an event', { skip: semver.lt(process.versions.node, '10.0.0') }, t => {
+test('Remove an event', t => {
   t.plan(4)
 
   const client = new Client({

test/unit/helpers/bulk.test.js

@@ -23,7 +23,6 @@ const { createReadStream } = require('fs')
 const { join } = require('path')
 const split = require('split2')
 const FakeTimers = require('@sinonjs/fake-timers')
-const semver = require('semver')
 const { test } = require('tap')
 const { Client, errors } = require('../../../')
 const { buildServer, connection } = require('../../utils')
@@ -308,10 +307,6 @@ test('bulk index', t => {
     })
 
     t.test('Should perform a bulk request (retry)', async t => {
-      if (semver.lt(process.versions.node, '10.0.0')) {
-        t.skip('This test will not pass on Node v8')
-        return
-      }
       async function handler (req, res) {
         t.strictEqual(req.url, '/_bulk')
         t.match(req.headers, { 'content-type': 'application/x-ndjson' })
@@ -430,10 +425,6 @@ test('bulk index', t => {
     })
 
     t.test('Should perform a bulk request (failure)', async t => {
-      if (semver.lt(process.versions.node, '10.0.0')) {
-        t.skip('This test will not pass on Node v8')
-        return
-      }
       async function handler (req, res) {
         t.strictEqual(req.url, '/_bulk')
         t.match(req.headers, { 'content-type': 'application/x-ndjson' })
@@ -575,10 +566,6 @@ test('bulk index', t => {
     })
 
     t.test('Should abort a bulk request', async t => {
-      if (semver.lt(process.versions.node, '10.0.0')) {
-        t.skip('This test will not pass on Node v8')
-        return
-      }
       async function handler (req, res) {
         t.strictEqual(req.url, '/_bulk')
         t.match(req.headers, { 'content-type': 'application/x-ndjson' })
@@ -667,7 +654,7 @@ test('bulk index', t => {
         })
         .catch(err => {
           t.true(err instanceof errors.ConfigurationError)
-          t.is(err.message, `Bulk helper invalid action: 'foo'`)
+          t.is(err.message, 'Bulk helper invalid action: \'foo\'')
         })
     })
 

test/unit/helpers/scroll.test.js

@@ -29,7 +29,7 @@ if (clientVersion.includes('-')) {
 const nodeVersion = process.versions.node
 
 test('Scroll search', async t => {
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       t.match(params.headers, {
@@ -52,10 +52,10 @@ test('Scroll search', async t => {
             hits: count === 3
               ? []
               : [
-                { _source: { one: 'one' } },
+                  { _source: { one: 'one' } },
-                { _source: { two: 'two' } },
+                  { _source: { two: 'two' } },
-                { _source: { three: 'three' } }
+                  { _source: { three: 'three' } }
-              ]
+                ]
           }
         }
       }
@@ -79,7 +79,7 @@ test('Scroll search', async t => {
 })
 
 test('Clear a scroll search', async t => {
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       t.notMatch(params.headers, {
@@ -129,7 +129,7 @@ test('Clear a scroll search', async t => {
 })
 
 test('Scroll search (retry)', async t => {
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       count += 1
@@ -149,10 +149,10 @@ test('Scroll search (retry)', async t => {
             hits: count === 4
               ? []
               : [
-                { _source: { one: 'one' } },
+                  { _source: { one: 'one' } },
-                { _source: { two: 'two' } },
+                  { _source: { two: 'two' } },
-                { _source: { three: 'three' } }
+                  { _source: { three: 'three' } }
-              ]
+                ]
           }
         }
       }
@@ -181,7 +181,7 @@ test('Scroll search (retry)', async t => {
 test('Scroll search (retry throws and maxRetries)', async t => {
   const maxRetries = 5
   const expectedAttempts = maxRetries + 1
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       count += 1
@@ -217,7 +217,7 @@ test('Scroll search (retry throws and maxRetries)', async t => {
 test('Scroll search (retry throws later)', async t => {
   const maxRetries = 5
   const expectedAttempts = maxRetries + 2
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       count += 1
@@ -268,7 +268,7 @@ test('Scroll search (retry throws later)', async t => {
 })
 
 test('Scroll search documents', async t => {
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       if (count === 0) {
@@ -287,10 +287,10 @@ test('Scroll search documents', async t => {
             hits: count === 3
               ? []
               : [
-                { _source: { val: 1 * count } },
+                  { _source: { val: 1 * count } },
-                { _source: { val: 2 * count } },
+                  { _source: { val: 2 * count } },
-                { _source: { val: 3 * count } }
+                  { _source: { val: 3 * count } }
-              ]
+                ]
           }
         }
       }
@@ -321,7 +321,7 @@ test('Scroll search documents', async t => {
 test('Should not retry if maxRetries = 0', async t => {
   const maxRetries = 0
   const expectedAttempts = 1
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       count += 1
@@ -355,7 +355,7 @@ test('Should not retry if maxRetries = 0', async t => {
 })
 
 test('Fix querystring for scroll search', async t => {
-  var count = 0
+  let count = 0
   const MockConnection = connection.buildMockConnection({
     onRequest (params) {
       if (count === 0) {
@@ -372,8 +372,8 @@ test('Fix querystring for scroll search', async t => {
             hits: count === 3
               ? []
               : [
-                { _source: { val: count } }
+                  { _source: { val: count } }
-              ]
+                ]
           }
         }
       }

test/unit/selectors.test.js

@@ -27,7 +27,7 @@ test('RoundRobinSelector', t => {
   const arr = [0, 1, 2, 3, 4, 5]
 
   t.plan(arr.length + 1)
-  for (var i = 0; i <= arr.length; i++) {
+  for (let i = 0; i <= arr.length; i++) {
     t.strictEqual(
       selector(arr),
       i === arr.length ? arr[0] : arr[i]

test/unit/transport.test.js

@@ -166,7 +166,7 @@ test('Send POST', t => {
       'content-type': 'application/json',
       'content-length': '17'
     })
-    var json = ''
+    let json = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { json += chunk })
     req.on('error', err => t.fail(err))
@@ -217,7 +217,7 @@ test('Send POST (ndjson)', t => {
       'content-type': 'application/x-ndjson',
       'content-length': '67'
     })
-    var json = ''
+    let json = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { json += chunk })
     req.on('error', err => t.fail(err))
@@ -265,7 +265,7 @@ test('Send stream', t => {
     t.match(req.headers, {
       'content-type': 'application/json'
     })
-    var json = ''
+    let json = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { json += chunk })
     req.on('error', err => t.fail(err))
@@ -308,7 +308,7 @@ test('Send stream (bulkBody)', t => {
     t.match(req.headers, {
       'content-type': 'application/x-ndjson'
     })
-    var json = ''
+    let json = ''
     req.setEncoding('utf8')
     req.on('data', chunk => { json += chunk })
     req.on('error', err => t.fail(err))
@@ -587,7 +587,7 @@ test('ConnectionError (should call markDead on the failing connection)', t => {
 test('Retry mechanism', t => {
   t.plan(2)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     res.setHeader('Content-Type', 'application/json;utf=8')
     if (count > 0) {
@@ -635,7 +635,7 @@ test('Retry mechanism', t => {
 test('Should not retry if the body is a stream', t => {
   t.plan(2)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     count++
     res.setHeader('Content-Type', 'application/json;utf=8')
@@ -680,7 +680,7 @@ test('Should not retry if the body is a stream', t => {
 test('Should not retry if the bulkBody is a stream', t => {
   t.plan(2)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     count++
     res.setHeader('Content-Type', 'application/json;utf=8')
@@ -725,7 +725,7 @@ test('Should not retry if the bulkBody is a stream', t => {
 test('No retry', t => {
   t.plan(2)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     count++
     res.setHeader('Content-Type', 'application/json;utf=8')
@@ -772,7 +772,7 @@ test('No retry', t => {
 test('Custom retry mechanism', t => {
   t.plan(2)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     res.setHeader('Content-Type', 'application/json;utf=8')
     if (count > 0) {
@@ -822,7 +822,7 @@ test('Custom retry mechanism', t => {
 test('Should not retry on 429', t => {
   t.plan(3)
 
-  var count = 0
+  let count = 0
   function handler (req, res) {
     t.strictEqual(count++, 0)
     res.statusCode = 429
@@ -988,7 +988,7 @@ test('Retry mechanism and abort', t => {
       id: 'node3'
     }])
 
-    var count = 0
+    let count = 0
     const transport = new Transport({
       emit: event => {
         if (event === 'request' && count++ > 0) {
@@ -1294,7 +1294,7 @@ test('Should retry the request if the statusCode is 502/3/4', t => {
     t.test(statusCode, t => {
       t.plan(3)
 
-      var first = true
+      let first = true
       function handler (req, res) {
         if (first) {
           first = false
@@ -1886,7 +1886,7 @@ test('asStream set to true', t => {
         'content-type': 'application/json;utf=8'
       })
 
-      var payload = ''
+      let payload = ''
       body.setEncoding('utf8')
       body.on('data', chunk => { payload += chunk })
       body.on('error', err => t.fail(err))
@@ -1906,7 +1906,7 @@ test('Compress request', t => {
         'content-type': 'application/json',
         'content-encoding': 'gzip'
       })
-      var json = ''
+      let json = ''
       req
         .pipe(createGunzip())
         .on('data', chunk => { json += chunk })
@@ -1953,7 +1953,7 @@ test('Compress request', t => {
         'content-type': 'application/json',
         'content-encoding': 'gzip'
       })
-      var json = ''
+      let json = ''
       req
         .pipe(createGunzip())
         .on('data', chunk => { json += chunk })
@@ -1999,7 +1999,7 @@ test('Compress request', t => {
         'content-type': 'application/json',
         'content-encoding': 'gzip'
       })
-      var json = ''
+      let json = ''
       req
         .pipe(createGunzip())
         .on('data', chunk => { json += chunk })
@@ -2112,13 +2112,13 @@ test('Compress request', t => {
   t.test('Retry a gzipped body', t => {
     t.plan(7)
 
-    var count = 0
+    let count = 0
     function handler (req, res) {
       t.match(req.headers, {
         'content-type': 'application/json',
         'content-encoding': 'gzip'
       })
-      var json = ''
+      let json = ''
       req
         .pipe(createGunzip())
         .on('data', chunk => { json += chunk })

test/utils/MockConnection.js

@@ -30,7 +30,7 @@ const intoStream = require('into-stream')
 
 class MockConnection extends Connection {
   request (params, callback) {
-    var aborted = false
+    let aborted = false
     const stream = intoStream(JSON.stringify({ hello: 'world' }))
     stream.statusCode = setStatusCode(params.path)
     stream.headers = {
@@ -54,7 +54,7 @@ class MockConnection extends Connection {
 
 class MockConnectionTimeout extends Connection {
   request (params, callback) {
-    var aborted = false
+    let aborted = false
     process.nextTick(() => {
       if (!aborted) {
         callback(new TimeoutError('Request timed out', params), null)
@@ -70,7 +70,7 @@ class MockConnectionTimeout extends Connection {
 
 class MockConnectionError extends Connection {
   request (params, callback) {
-    var aborted = false
+    let aborted = false
     process.nextTick(() => {
       if (!aborted) {
         callback(new ConnectionError('Kaboom'), null)
@@ -86,7 +86,7 @@ class MockConnectionError extends Connection {
 
 class MockConnectionSniff extends Connection {
   request (params, callback) {
-    var aborted = false
+    let aborted = false
     const sniffResult = {
       nodes: {
         'node-1': {
@@ -133,11 +133,11 @@ function buildMockConnection (opts) {
 
   class MockConnection extends Connection {
     request (params, callback) {
-      var { body, statusCode } = opts.onRequest(params)
+      let { body, statusCode } = opts.onRequest(params)
       if (typeof body !== 'string') {
         body = JSON.stringify(body)
       }
-      var aborted = false
+      let aborted = false
       const stream = intoStream(body)
       stream.statusCode = statusCode || 200
       stream.headers = {

test/utils/buildCluster.js

@@ -23,7 +23,7 @@ const debug = require('debug')('elasticsearch-test')
 const workq = require('workq')
 const buildServer = require('./buildServer')
 
-var id = 0
+let id = 0
 function buildCluster (options, callback) {
   const clusterId = id++
   debug(`Booting cluster '${clusterId}'`)
@@ -37,7 +37,7 @@ function buildCluster (options, callback) {
   const sniffResult = { nodes: {} }
 
   options.numberOfNodes = options.numberOfNodes || 4
-  for (var i = 0; i < options.numberOfNodes; i++) {
+  for (let i = 0; i < options.numberOfNodes; i++) {
     q.add(bootNode, { id: `node${i}` })
   }
 

test/utils/buildServer.js

@@ -35,7 +35,7 @@ const secureOpts = {
   cert: readFileSync(join(__dirname, '..', 'fixtures', 'https.cert'), 'utf8')
 }
 
-var id = 0
+let id = 0
 function buildServer (handler, opts, cb) {
   const serverId = id++
   debug(`Booting server '${serverId}'`)