Update helpers to use new multisearch types (#2697) (#2698)

* Update helpers to use correct multisearch types

The spec combined definitions for search and multisearch bodies in
https://github.com/elastic/elasticsearch-specification/pull/2960.

* Stop copying project files to Dockerfile

Slightly faster run times for codegen, hopefully.

(cherry picked from commit b2a490718d)

Co-authored-by: Josh Mock <joshua.mock@elastic.co>

.buildkite/Dockerfile

@@ -12,5 +12,3 @@ WORKDIR /usr/src/app
 
 COPY package.json .
 RUN npm install
-
-COPY . .

.buildkite/Dockerfile-make

@@ -25,6 +25,3 @@ USER ${BUILDER_UID}:${BUILDER_GID}
 # install dependencies
 COPY package.json .
 RUN npm install
-
-# copy project files
-COPY . .

src/helpers.ts

@@ -41,7 +41,7 @@ export interface MsearchHelperOptions extends T.MsearchRequest {
 
 export interface MsearchHelper extends Promise<void> {
   stop: (error?: Error | null) => void
-  search: <TDocument = unknown>(header: T.MsearchMultisearchHeader, body: T.MsearchMultisearchBody) => Promise<MsearchHelperResponse<TDocument>>
+  search: <TDocument = unknown>(header: T.MsearchMultisearchHeader, body: T.SearchSearchRequestBody) => Promise<MsearchHelperResponse<TDocument>>
 }
 
 export interface MsearchHelperResponse<TDocument> {
@@ -362,7 +362,7 @@ export default class Helpers {
       // TODO: support abort a single search?
       // NOTE: the validation checks are synchronous and the callback/promise will
       //       be resolved in the same tick. We might want to fix this in the future.
-      search<TDocument = unknown> (header: T.MsearchMultisearchHeader, body: T.MsearchMultisearchBody): Promise<MsearchHelperResponse<TDocument>> {
+      search<TDocument = unknown> (header: T.MsearchMultisearchHeader, body: T.SearchSearchRequestBody): Promise<MsearchHelperResponse<TDocument>> {
         if (stopReading) {
           const error = stopError === null
             ? new ConfigurationError('The msearch processor has been stopped')
@@ -397,7 +397,7 @@ export default class Helpers {
 
     async function iterate (): Promise<void> {
       const { semaphore, finish } = buildSemaphore()
-      const msearchBody: Array<T.MsearchMultisearchHeader | T.MsearchMultisearchBody> = []
+      const msearchBody: Array<T.MsearchMultisearchHeader | T.SearchSearchRequestBody> = []
       const callbacks: any[] = []
       let loadedOperations = 0
       timeoutRef = setTimeout(onFlushTimeout, flushInterval) // eslint-disable-line
@@ -490,7 +490,7 @@ export default class Helpers {
         }
       }
 
-      function send (msearchBody: Array<T.MsearchMultisearchHeader | T.MsearchMultisearchBody>, callbacks: any[]): void {
+      function send (msearchBody: Array<T.MsearchMultisearchHeader | T.SearchSearchRequestBody>, callbacks: any[]): void {
         /* istanbul ignore if */
         if (running > concurrency) {
           throw new Error('Max concurrency reached')
@@ -508,7 +508,7 @@ export default class Helpers {
       }
     }
 
-    function msearchOperation (msearchBody: Array<T.MsearchMultisearchHeader | T.MsearchMultisearchBody>, callbacks: any[], done: () => void): void {
+    function msearchOperation (msearchBody: Array<T.MsearchMultisearchHeader | T.SearchSearchRequestBody>, callbacks: any[], done: () => void): void {
       let retryCount = retries
 
       // Instead of going full on async-await, which would make the code easier to read,
@@ -516,7 +516,7 @@ export default class Helpers {
       // This because every time we use async await, V8 will create multiple promises
       // behind the scenes, making the code slightly slower.
       tryMsearch(msearchBody, callbacks, retrySearch)
-      function retrySearch (msearchBody: Array<T.MsearchMultisearchHeader | T.MsearchMultisearchBody>, callbacks: any[]): void {
+      function retrySearch (msearchBody: Array<T.MsearchMultisearchHeader | T.SearchSearchRequestBody>, callbacks: any[]): void {
         if (msearchBody.length > 0 && retryCount > 0) {
           retryCount -= 1
           setTimeout(tryMsearch, wait, msearchBody, callbacks, retrySearch)
@@ -528,7 +528,7 @@ export default class Helpers {
 
       // This function never returns an error, if the msearch operation fails,
       // the error is dispatched to all search executors.
-      function tryMsearch (msearchBody: Array<T.MsearchMultisearchHeader | T.MsearchMultisearchBody>, callbacks: any[], done: (msearchBody: Array<T.MsearchMultisearchHeader | T.MsearchMultisearchBody>, callbacks: any[]) => void): void {
+      function tryMsearch (msearchBody: Array<T.MsearchMultisearchHeader | T.SearchSearchRequestBody>, callbacks: any[], done: (msearchBody: Array<T.MsearchMultisearchHeader | T.SearchSearchRequestBody>, callbacks: any[]) => void): void {
         client.msearch(Object.assign({}, msearchOptions, { body: msearchBody }), reqOptions as TransportRequestOptionsWithMeta)
           .then(results => {
             const retryBody = []