Remove dead parallelism options and narrow public API

The parallelism fields on bundler types (BundlingOptions, BuildOptions,
BackendBundlingOptions) and createDistWorkspace Options were defined but
never read — fully dead code. Likewise the parallelismSetting option on
ParallelWorkerOptions was never passed by any caller.

Also narrows the cli-node public API to only export the three runner
functions and their option types, keeping getEnvironmentParallelism and
parseParallelismOption as internal utilities.

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/cli-node-parallel-helpers.md

@@ -2,4 +2,4 @@
 '@backstage/cli-node': minor
 ---
 
-Added parallel worker utilities: `runParallelWorkers`, `runWorkerQueueThreads`, `runWorkerThreads`, `parseParallelismOption`, and `getEnvironmentParallelism`. These were moved from the `@backstage/cli` internal code.
+Added parallel worker utilities: `runParallelWorkers`, `runWorkerQueueThreads`, and `runWorkerThreads`. These were moved from the `@backstage/cli` internal code.

packages/cli-node/report.api.md

@@ -86,9 +86,6 @@ export interface BackstagePackageJson {
   version: string;
 }
 
-// @public
-export function getEnvironmentParallelism(): number;
-
 // @public
 export class GitUtils {
   static listChangedFiles(ref: string): Promise<string[]>;
@@ -204,20 +201,13 @@ export class PackageRoles {
   static getRoleInfo(role: string): PackageRoleInfo;
 }
 
-// @public
-export type ParallelismOption = boolean | string | number | null | undefined;
-
 // @public
 export type ParallelWorkerOptions<TItem> = {
   parallelismFactor?: number;
-  parallelismSetting?: ParallelismOption;
   items: Iterable<TItem>;
   worker: (item: TItem) => Promise<void>;
 };
 
-// @public
-export function parseParallelismOption(parallel: ParallelismOption): number;
-
 // @public
 export function runParallelWorkers<TItem>(
   options: ParallelWorkerOptions<TItem>,

packages/cli-node/src/parallel/index.ts

@@ -14,10 +14,8 @@
  * limitations under the License.
  */
 
-export type { ParallelismOption, ParallelWorkerOptions } from './parallel';
+export type { ParallelWorkerOptions } from './parallel';
 export {
-  parseParallelismOption,
-  getEnvironmentParallelism,
   runParallelWorkers,
   runWorkerQueueThreads,
   runWorkerThreads,

packages/cli-node/src/parallel/parallel.test.ts

@@ -66,14 +66,18 @@ describe('getEnvironmentParallelism', () => {
 });
 
 describe('runParallelWorkers', () => {
+  afterEach(() => {
+    delete process.env.BACKSTAGE_CLI_BUILD_PARALLEL;
+  });
+
   it('executes work in parallel', async () => {
     const started = new Array<number>();
     const done = new Array<number>();
     const waiting = new Array<() => void>();
 
+    process.env.BACKSTAGE_CLI_BUILD_PARALLEL = '4';
     const work = runParallelWorkers({
       items: [0, 1, 2, 3, 4],
-      parallelismSetting: 4,
       parallelismFactor: 0.5, // 2 at a time
       worker: async item => {
         started.push(item);

packages/cli-node/src/parallel/parallel.ts

@@ -22,21 +22,8 @@ const defaultParallelism = Math.ceil(os.cpus().length / 2);
 
 const PARALLEL_ENV_VAR = 'BACKSTAGE_CLI_BUILD_PARALLEL';
 
-/**
- * Options for configuring parallelism. Can be a boolean, string, number, null, or undefined.
- * - Boolean: true uses default parallelism (half of CPUs), false uses 1
- * - Number: explicit worker count
- * - String: parsed as boolean or integer (e.g. "true", "4")
- *
- * @public
- */
 export type ParallelismOption = boolean | string | number | null | undefined;
 
-/**
- * Parses a parallelism option value into a concrete worker count.
- *
- * @public
- */
 export function parseParallelismOption(parallel: ParallelismOption): number {
   if (parallel === undefined || parallel === null) {
     return defaultParallelism;
@@ -64,11 +51,6 @@ export function parseParallelismOption(parallel: ParallelismOption): number {
   );
 }
 
-/**
- * Returns the parallelism value from the BACKSTAGE_CLI_BUILD_PARALLEL environment variable.
- *
- * @public
- */
 export function getEnvironmentParallelism() {
   return parseParallelismOption(process.env[PARALLEL_ENV_VAR]);
 }
@@ -86,7 +68,6 @@ export type ParallelWorkerOptions<TItem> = {
    * Defaults to 1.
    */
   parallelismFactor?: number;
-  parallelismSetting?: ParallelismOption;
   items: Iterable<TItem>;
   worker: (item: TItem) => Promise<void>;
 };
@@ -99,10 +80,8 @@ export type ParallelWorkerOptions<TItem> = {
 export async function runParallelWorkers<TItem>(
   options: ParallelWorkerOptions<TItem>,
 ) {
-  const { parallelismFactor = 1, parallelismSetting, items, worker } = options;
-  const parallelism = parallelismSetting
-    ? parseParallelismOption(parallelismSetting)
-    : getEnvironmentParallelism();
+  const { parallelismFactor = 1, items, worker } = options;
+  const parallelism = getEnvironmentParallelism();
 
   const sharedIterator = items[Symbol.iterator]();
   const sharedIterable = {

packages/cli/src/modules/build/lib/buildBackend.ts

@@ -20,7 +20,7 @@ import { resolve as resolvePath } from 'node:path';
 import * as tar from 'tar';
 import { createDistWorkspace } from './packager';
 import { buildPackage, Output } from './builder';
-import { PackageGraph, getEnvironmentParallelism } from '@backstage/cli-node';
+import { PackageGraph } from '@backstage/cli-node';
 
 const BUNDLE_FILE = 'bundle.tar.gz';
 const SKELETON_FILE = 'skeleton.tar.gz';
@@ -52,7 +52,6 @@ export async function buildBackend(options: BuildBackendOptions) {
       configPaths,
       buildDependencies: !skipBuildDependencies,
       buildExcludes: [pkg.name],
-      parallelism: getEnvironmentParallelism(),
       skeleton: SKELETON_FILE,
       minify,
     });

packages/cli/src/modules/build/lib/buildFrontend.ts

@@ -17,10 +17,7 @@
 import fs from 'fs-extra';
 import { resolve as resolvePath } from 'node:path';
 import { buildBundle, getModuleFederationRemoteOptions } from './bundler';
-import {
-  BackstagePackageJson,
-  getEnvironmentParallelism,
-} from '@backstage/cli-node';
+import { BackstagePackageJson } from '@backstage/cli-node';
 import { loadCliConfig } from '../../config/lib/config';
 
 interface BuildAppOptions {
@@ -39,7 +36,6 @@ export async function buildFrontend(options: BuildAppOptions) {
   await buildBundle({
     targetDir,
     entry: 'src/index',
-    parallelism: getEnvironmentParallelism(),
     statsJsonEnabled: writeStats,
     moduleFederationRemote: options.isModuleFederationRemote
       ? await getModuleFederationRemoteOptions(

packages/cli/src/modules/build/lib/bundler/types.ts

@@ -36,7 +36,6 @@ export type BundlingOptions = {
   isDev: boolean;
   frontendConfig: Config;
   getFrontendAppConfigs(): AppConfig[];
-  parallelism?: number;
   additionalEntryPoints?: string[];
   // Path to append to the detected public path, e.g. '/public'
   publicSubPath?: string;
@@ -63,7 +62,6 @@ export type BuildOptions = BundlingPathsOptions & {
   // Target directory, defaulting to paths.targetDir
   targetDir?: string;
   statsJsonEnabled: boolean;
-  parallelism?: number;
   schema?: ConfigSchema;
   frontendConfig: Config;
   frontendAppConfigs: AppConfig[];
@@ -75,7 +73,6 @@ export type BuildOptions = BundlingPathsOptions & {
 export type BackendBundlingOptions = {
   checksEnabled: boolean;
   isDev: boolean;
-  parallelism?: number;
   inspectEnabled: boolean;
   inspectBrkEnabled: boolean;
   require?: string;

packages/cli/src/modules/build/lib/packager/createDistWorkspace.ts

@@ -86,11 +86,6 @@ type Options = {
    */
   buildExcludes?: string[];
 
-  /**
-   * Controls amount of parallelism in some build steps.
-   */
-  parallelism?: number;
-
   /**
    * If set, creates a skeleton tarball that contains all package.json files
    * with the same structure as the workspace dir.