chore(gatsby): type exposed workerpool functions

packages/gatsby/src/bootstrap/index.ts

@@ -14,7 +14,7 @@ import {
 import { Runner, createGraphQLRunner } from "./create-graphql-runner"
 import reporter from "gatsby-cli/lib/reporter"
 import { globalTracer } from "opentracing"
-import JestWorker from "jest-worker"
+import type { GatsbyWorkerPool } from "../utils/worker/pool"
 import { handleStalePageData } from "../utils/page-data"
 
 const tracer = globalTracer()
@@ -23,7 +23,7 @@ export async function bootstrap(
   initialContext: Partial<IBuildContext>
 ): Promise<{
   gatsbyNodeGraphQLFunction: Runner
-  workerPool: JestWorker
+  workerPool: GatsbyWorkerPool
 }> {
   const spanArgs = initialContext.parentSpan
     ? { childOf: initialContext.parentSpan }

packages/gatsby/src/commands/build-html.ts

@@ -15,9 +15,9 @@ import * as buildUtils from "./build-utils"
 import { Span } from "opentracing"
 import { IProgram, Stage } from "./types"
 import { PackageJson } from "../.."
+import type { GatsbyWorkerPool } from "../utils/worker/pool"
 
 type IActivity = any // TODO
-type IWorkerPool = any // TODO
 
 export interface IBuildArgs extends IProgram {
   directory: string
@@ -193,15 +193,15 @@ export interface IRenderHtmlResult {
 }
 
 const renderHTMLQueue = async (
-  workerPool: IWorkerPool,
+  workerPool: GatsbyWorkerPool,
   activity: IActivity,
   htmlComponentRendererPath: string,
   pages: Array<string>,
   stage: Stage = Stage.BuildHTML
 ): Promise<void> => {
   // We need to only pass env vars that are set programmatically in gatsby-cli
   // to child process. Other vars will be picked up from environment.
-  const envVars = [
+  const envVars: Array<[string, string | undefined]> = [
     [`NODE_ENV`, process.env.NODE_ENV],
     [`gatsby_executing_command`, process.env.gatsby_executing_command],
     [`gatsby_log_level`, process.env.gatsby_log_level],
@@ -220,14 +220,15 @@ const renderHTMLQueue = async (
 
   try {
     await Bluebird.map(segments, async pageSegment => {
-      const htmlRenderMeta: IRenderHtmlResult = await renderHTML({
+      const renderHTMLResult = await renderHTML({
         envVars,
         htmlComponentRendererPath,
         paths: pageSegment,
         sessionId,
       })
 
       if (stage === `build-html`) {
+        const htmlRenderMeta = renderHTMLResult as IRenderHtmlResult
         store.dispatch({
           type: `HTML_GENERATED`,
           payload: pageSegment,
@@ -304,7 +305,7 @@ export const doBuildPages = async (
   rendererPath: string,
   pagePaths: Array<string>,
   activity: IActivity,
-  workerPool: IWorkerPool,
+  workerPool: GatsbyWorkerPool,
   stage: Stage
 ): Promise<void> => {
   try {
@@ -332,7 +333,7 @@ export const buildHTML = async ({
   stage: Stage
   pagePaths: Array<string>
   activity: IActivity
-  workerPool: IWorkerPool
+  workerPool: GatsbyWorkerPool
 }): Promise<void> => {
   const { rendererPath } = await buildRenderer(program, stage, activity.span)
   await doBuildPages(rendererPath, pagePaths, activity, workerPool, stage)
@@ -346,7 +347,7 @@ export async function buildHTMLPagesAndDeleteStaleArtifacts({
   program,
 }: {
   pageRenderer: string
-  workerPool: IWorkerPool
+  workerPool: GatsbyWorkerPool
   buildSpan?: Span
   program: IBuildArgs
 }): Promise<{

packages/gatsby/src/services/initialize.ts

@@ -13,7 +13,6 @@ import { getBrowsersList } from "../utils/browserslist"
 import { Store, AnyAction } from "redux"
 import { preferDefault } from "../bootstrap/prefer-default"
 import * as WorkerPool from "../utils/worker/pool"
-import JestWorker from "jest-worker"
 import { startPluginRunner } from "../redux/plugin-runner"
 import { loadPlugins } from "../bootstrap/load-plugins"
 import { store, emitter } from "../redux"
@@ -76,7 +75,7 @@ export async function initialize({
   parentSpan,
 }: IBuildContext): Promise<{
   store: Store<IGatsbyState, AnyAction>
-  workerPool: JestWorker
+  workerPool: WorkerPool.GatsbyWorkerPool
 }> {
   if (process.env.GATSBY_DISABLE_CACHE_PERSISTENCE) {
     reporter.info(

packages/gatsby/src/services/types.ts

@@ -5,7 +5,7 @@ import { GraphQLRunner } from "../query/graphql-runner"
 import { Store, AnyAction } from "redux"
 import { IGatsbyState } from "../redux/types"
 import { Express } from "express"
-import JestWorker from "jest-worker"
+import type { GatsbyWorkerPool } from "../utils/worker/pool"
 import { Actor, AnyEventObject } from "xstate"
 import { Compiler } from "webpack"
 import { WebsocketManager } from "../utils/websocket-manager"
@@ -30,7 +30,7 @@ export interface IBuildContext {
   webhookBody?: Record<string, unknown>
   webhookSourcePluginName?: string
   refresh?: boolean
-  workerPool?: JestWorker
+  workerPool?: GatsbyWorkerPool
   app?: Express
   nodesMutatedDuringQueryRun?: boolean
   nodesMutatedDuringQueryRunRecompileCount?: number

packages/gatsby/src/state-machines/data-layer/types.ts

@@ -4,7 +4,7 @@ import { Runner } from "../../bootstrap/create-graphql-runner"
 import { GraphQLRunner } from "../../query/graphql-runner"
 import { Store, AnyAction } from "redux"
 import { IGatsbyState } from "../../redux/types"
-import JestWorker from "jest-worker"
+import type { GatsbyWorkerPool } from "../../utils/worker/pool"
 export interface IGroupedQueryIds {
   pageQueryIds: Array<string>
   staticQueryIds: Array<string>
@@ -25,7 +25,7 @@ export interface IDataLayerContext {
   webhookBody?: Record<string, unknown>
   webhookSourcePluginName?: string
   refresh?: boolean
-  workerPool?: JestWorker
+  workerPool?: GatsbyWorkerPool
   pagesToBuild?: Array<string>
   pagesToDelete?: Array<string>
   shouldRunCreatePagesStatefully?: boolean

packages/gatsby/src/utils/start-server.ts

@@ -41,7 +41,6 @@ import { Express } from "express"
 import * as path from "path"
 
 import { Stage, IProgram } from "../commands/types"
-import JestWorker from "jest-worker"
 import { findOriginalSourcePositionAndContent } from "./stack-trace-utils"
 import { appendPreloadHeaders } from "./develop-preload-headers"
 import {
@@ -58,7 +57,7 @@ interface IServer {
   webpackActivity: ActivityTracker
   cancelDevJSNotice: CancelExperimentNoticeCallbackOrUndefined
   websocketManager: WebsocketManager
-  workerPool: JestWorker
+  workerPool: WorkerPool.GatsbyWorkerPool
   webpackWatching: IWebpackWatchingPauseResume
 }
 
@@ -70,7 +69,7 @@ export interface IWebpackWatchingPauseResume {
 export async function startServer(
   program: IProgram,
   app: Express,
-  workerPool: JestWorker = WorkerPool.create()
+  workerPool: WorkerPool.GatsbyWorkerPool = WorkerPool.create()
 ): Promise<IServer> {
   const directory = program.directory
 

packages/gatsby/src/utils/worker/pool.ts

@@ -1,10 +1,18 @@
 import Worker from "jest-worker"
 import { cpuCoreCount } from "gatsby-core-utils"
 
-export const create = (): Worker =>
+// we only import it to get types, typescript will remove it from code if it's only used for types
+import * as exposedWorkerPoolMethods from "./child"
+import type { CreateWorkerPoolType } from "./types"
+
+export type GatsbyWorkerPool = CreateWorkerPoolType<
+  typeof exposedWorkerPoolMethods
+>
+
+export const create = (): GatsbyWorkerPool =>
   new Worker(require.resolve(`./child`), {
     numWorkers: Math.max(1, cpuCoreCount() - 1),
     forkOptions: {
       silent: false,
     },
-  })
+  }) as GatsbyWorkerPool

packages/gatsby/src/utils/worker/render-html.ts

@@ -280,7 +280,7 @@ export const renderHTMLProd = async ({
 }: {
   htmlComponentRendererPath: string
   paths: Array<string>
-  envVars: Array<Array<string>>
+  envVars: Array<[string, string | undefined]>
   sessionId: number
 }): Promise<IRenderHtmlResult> => {
   const publicDir = join(process.cwd(), `public`)
@@ -353,7 +353,7 @@ export const renderHTMLDev = async ({
 }: {
   htmlComponentRendererPath: string
   paths: Array<string>
-  envVars: Array<Array<string>>
+  envVars: Array<[string, string | undefined]>
   sessionId: number
 }): Promise<Array<unknown>> => {
   const outputDir = join(process.cwd(), `.cache`, `develop-html`)

packages/gatsby/src/utils/worker/types.ts

@@ -0,0 +1,24 @@
+import type Worker from "jest-worker"
+
+type WrapReturnOfAFunctionInAPromise<
+  FunctionThatDoesNotReturnAPromise extends (...args: Array<any>) => any
+> = (
+  ...a: Parameters<FunctionThatDoesNotReturnAPromise>
+) => Promise<ReturnType<FunctionThatDoesNotReturnAPromise>>
+
+// jest-worker will make sync function async, so to keep proper types we need to adjust types so all functions
+// on worker pool are async
+type EnsureFunctionReturnsAPromise<MaybeFunction> = MaybeFunction extends (
+  ...args: Array<any>
+) => Promise<any>
+  ? MaybeFunction
+  : MaybeFunction extends (...args: Array<any>) => any
+  ? WrapReturnOfAFunctionInAPromise<MaybeFunction>
+  : never
+
+export type CreateWorkerPoolType<ExposedFunctions> = Worker &
+  {
+    [FunctionName in keyof ExposedFunctions]: EnsureFunctionReturnsAPromise<
+      ExposedFunctions[FunctionName]
+    >
+  }