[jest] try running unit tests in parallel (#130823)

packages/kbn-cli-dev-mode/src/dev_server.test.ts

@@ -72,6 +72,7 @@ const defaultOptions: Options = {
   processExit$,
   sigint$,
   sigterm$,
+  forceColor: true,
 };
 
 expect.addSnapshotSerializer(extendedEnvSerializer);
@@ -80,7 +81,6 @@ beforeEach(() => {
   jest.clearAllMocks();
   log.messages.length = 0;
   process.execArgv = ['--inheritted', '--exec', '--argv'];
-  process.env.FORCE_COLOR = process.env.FORCE_COLOR || '1';
   currentProc = undefined;
 });
 

packages/kbn-cli-dev-mode/src/dev_server.ts

@@ -34,6 +34,7 @@ export interface Options {
   sigint$?: Rx.Observable<void>;
   sigterm$?: Rx.Observable<void>;
   mapLogLine?: DevServer['mapLogLine'];
+  forceColor?: boolean;
 }
 
 export class DevServer {
@@ -50,6 +51,7 @@ export class DevServer {
   private readonly argv: string[];
   private readonly gracefulTimeout: number;
   private readonly mapLogLine?: (line: string) => string | null;
+  private readonly forceColor: boolean;
 
   constructor(options: Options) {
     this.log = options.log;
@@ -62,6 +64,7 @@ export class DevServer {
     this.sigint$ = options.sigint$ ?? Rx.fromEvent<void>(process, 'SIGINT');
     this.sigterm$ = options.sigterm$ ?? Rx.fromEvent<void>(process, 'SIGTERM');
     this.mapLogLine = options.mapLogLine;
+    this.forceColor = options.forceColor ?? !!process.stdout.isTTY;
   }
 
   isReady$() {
@@ -141,8 +144,13 @@ export class DevServer {
       })
     );
 
+    const serverOptions = {
+      script: this.script,
+      argv: this.argv,
+      forceColor: this.forceColor,
+    };
     const runServer = () =>
-      usingServerProcess(this.script, this.argv, (proc) => {
+      usingServerProcess(serverOptions, (proc) => {
         this.phase$.next('starting');
         this.ready$.next(false);
 

packages/kbn-cli-dev-mode/src/using_server_process.ts

@@ -18,14 +18,19 @@ interface ProcResource extends Rx.Unsubscribable {
   unsubscribe(): void;
 }
 
+interface Options {
+  script: string;
+  argv: string[];
+  forceColor: boolean;
+}
+
 export function usingServerProcess<T>(
-  script: string,
-  argv: string[],
+  options: Options,
   fn: (proc: execa.ExecaChildProcess) => Rx.Observable<T>
 ) {
   return Rx.using(
     (): ProcResource => {
-      const proc = execa.node(script, argv, {
+      const proc = execa.node(options.script, options.argv, {
         stdio: 'pipe',
         nodeOptions: [
           ...process.execArgv,
@@ -36,7 +41,7 @@ export function usingServerProcess<T>(
           NODE_OPTIONS: process.env.NODE_OPTIONS,
           isDevCliChild: 'true',
           ELASTIC_APM_SERVICE_NAME: 'kibana',
-          ...(process.stdout.isTTY ? { FORCE_COLOR: 'true' } : {}),
+          ...(options.forceColor ? { FORCE_COLOR: 'true' } : {}),
         },
       });