Revert most changes

Signed-off-by: Gabriel Dugny <gabriel.dugny@believe.com>

.changeset/slick-dogs-pay.md

@@ -1,5 +1,4 @@
 ---
-'@backstage/cli-common': patch
 '@backstage/create-app': patch
 '@backstage/cli-node': patch
 '@backstage/cli': patch

packages/cli-common/report.api.md

@@ -23,9 +23,6 @@ export class ExitCodeError extends CustomErrorBase {
 // @public
 export function findPaths(searchDir: string): Paths;
 
-// @public
-export function getWorkspacesPatterns(pkgJson: unknown): string[];
-
 // @public
 export function isChildPath(base: string, path: string): boolean;
 

packages/cli-common/src/index.ts

@@ -21,7 +21,6 @@
  */
 
 export { findPaths, BACKSTAGE_JSON } from './paths';
-export { getWorkspacesPatterns } from './workspaces';
 export { isChildPath } from './isChildPath';
 export type { Paths, ResolveFunc } from './paths';
 export { bootstrapEnvProxyAgents } from './proxyBootstrap';

packages/cli-common/src/paths.ts

@@ -16,7 +16,6 @@
 
 import fs from 'node:fs';
 import { dirname, resolve as resolvePath } from 'node:path';
-import { getWorkspacesPatterns } from './workspaces';
 
 /**
  * A function that takes a set of path fragments and resolves them into a
@@ -142,7 +141,7 @@ export function findPaths(searchDir: string): Paths {
           try {
             const content = fs.readFileSync(path, 'utf8');
             const data = JSON.parse(content);
-            return getWorkspacesPatterns(data).length > 0;
+            return Boolean(data.workspaces);
           } catch (error) {
             throw new Error(
               `Failed to parse package.json file while searching for root, ${error}`,

packages/cli-common/src/workspaces.test.ts

@@ -1,69 +0,0 @@
-/*
- * Copyright 2026 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import { getWorkspacesPatterns } from './workspaces';
-
-describe('getWorkspacesPatterns', () => {
-  it('returns empty array when pkgJson has no workspaces key', () => {
-    expect(getWorkspacesPatterns({ name: 'pkg' })).toEqual([]);
-  });
-
-  it('returns patterns when workspaces is array form', () => {
-    const patterns = ['packages/*', 'apps/*'];
-    expect(getWorkspacesPatterns({ workspaces: patterns })).toEqual(patterns);
-  });
-
-  it('returns patterns when workspaces is object form with packages', () => {
-    const patterns = ['packages/*'];
-    expect(
-      getWorkspacesPatterns({ workspaces: { packages: patterns } }),
-    ).toEqual(patterns);
-  });
-
-  it('returns empty array when workspaces is object without packages array', () => {
-    expect(getWorkspacesPatterns({ workspaces: {} })).toEqual([]);
-    expect(getWorkspacesPatterns({ workspaces: { noMatch: [] } })).toEqual([]);
-  });
-
-  it('throws when pkgJson is not an object', () => {
-    expect(() => getWorkspacesPatterns(null)).toThrow(
-      'pkgJson must be an object',
-    );
-    expect(() => getWorkspacesPatterns('string')).toThrow(
-      'pkgJson must be an object',
-    );
-    expect(() => getWorkspacesPatterns(42)).toThrow(
-      'pkgJson must be an object',
-    );
-  });
-
-  it('throws when workspaces array contains non-strings', () => {
-    expect(() => getWorkspacesPatterns({ workspaces: ['a', 1, 'b'] })).toThrow(
-      'must be an array of strings',
-    );
-    expect(() => getWorkspacesPatterns({ workspaces: [null] })).toThrow(
-      'must be an array of strings',
-    );
-  });
-
-  it('throws when workspaces.packages contains non-strings', () => {
-    expect(() =>
-      getWorkspacesPatterns({
-        workspaces: { packages: ['a', 1] },
-      }),
-    ).toThrow('must be an array of strings');
-  });
-});

packages/cli-common/src/workspaces.ts

@@ -1,63 +0,0 @@
-/*
- * Copyright 2026 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-function assertStringArray(
-  value: unknown,
-  field: string,
-): asserts value is string[] {
-  if (!Array.isArray(value)) {
-    throw new Error(`${field} must be an array`);
-  }
-  if (!value.every((item): item is string => typeof item === 'string')) {
-    throw new Error(`${field} must be an array of strings`);
-  }
-}
-
-/**
- * Gets the workspaces patterns from a package.json object.
- *
- * Supports both the array form (`"workspaces": ["packages/*"]`) and the object
- * form (`"workspaces": { "packages": ["packages/*"] }`) from npm/yarn.
- *
- * @param pkgJson - The package.json object. Type as `unknown` so callers must pass parsed JSON; an object type check is performed.
- * @returns The workspaces patterns (globs not resolved). Empty array if none.
- * @throws Error if `pkgJson` is not an object or workspaces/packages contain non-strings.
- * @public
- */
-export function getWorkspacesPatterns(pkgJson: unknown): string[] {
-  if (typeof pkgJson !== 'object' || pkgJson === null) {
-    throw new Error('pkgJson must be an object');
-  }
-  if (!('workspaces' in pkgJson)) {
-    return [];
-  }
-
-  const workspaces = pkgJson.workspaces;
-  if (Array.isArray(workspaces)) {
-    assertStringArray(workspaces, 'pkgJson.workspaces');
-    return workspaces;
-  }
-  if (
-    typeof workspaces === 'object' &&
-    workspaces !== null &&
-    'packages' in workspaces &&
-    Array.isArray(workspaces.packages)
-  ) {
-    assertStringArray(workspaces.packages, 'pkgJson.workspaces.packages');
-    return workspaces.packages;
-  }
-  return [];
-}

packages/cli-node/src/monorepo/isMonoRepo.ts

@@ -14,12 +14,14 @@
  * limitations under the License.
  */
 
-import { getWorkspacesPatterns } from '@backstage/cli-common';
 import { paths } from '../paths';
 import fs from 'fs-extra';
 
 /**
- * Returns try if the current project is a monorepo.
+ * Returns true if the current project is a monorepo.
+ *
+ * Uses a simple presence check on the `workspaces` field. Empty or invalid
+ * workspace config is treated as a monorepo; we do not validate patterns.
  *
  * @public
  */
@@ -27,7 +29,7 @@ export async function isMonoRepo(): Promise<boolean> {
   const rootPackageJsonPath = paths.resolveTargetRoot('package.json');
   try {
     const pkg = await fs.readJson(rootPackageJsonPath);
-    return getWorkspacesPatterns(pkg).length > 0;
+    return Boolean(pkg?.workspaces);
   } catch (error) {
     return false;
   }

packages/cli-node/src/pacman/PackageManager.test.ts

@@ -43,19 +43,19 @@ describe('PackageManager', () => {
         expect(mockYarnCreate).toHaveBeenCalled();
       });
 
-      it('should detect via root package.json workspaces with legacy workspaces.packages field', async () => {
+      it('should detect via root package.json workspaces', async () => {
         mockDir.setContent({
           'package.json': JSON.stringify({
             name: 'foo',
             workspaces: {
-              packages: ['packages/*'],
+              packages: [],
             },
           }),
         });
         await detectPackageManager();
         expect(mockYarnCreate).toHaveBeenCalled();
       });
-      it('should detect via root package.json workspaces', async () => {
+      it('should detect via root package.json workspaces (array form)', async () => {
         mockDir.setContent({
           'package.json': JSON.stringify({
             name: 'foo',

packages/cli-node/src/pacman/PackageManager.ts

@@ -17,7 +17,7 @@
 import { Yarn } from './yarn';
 import { Lockfile } from './Lockfile';
 import { paths } from '../paths';
-import { getWorkspacesPatterns, RunOptions } from '@backstage/cli-common';
+import { RunOptions } from '@backstage/cli-common';
 import fs from 'fs-extra';
 
 /**
@@ -101,7 +101,7 @@ export async function detectPackageManager(): Promise<PackageManager> {
     const packageJson = await fs.readJson(
       paths.resolveTargetRoot('package.json'),
     );
-    if (getWorkspacesPatterns(packageJson).length > 0) {
+    if (packageJson.workspaces) {
       // technically this could be NPM as well
       return await Yarn.create();
     }

packages/cli-node/src/pacman/yarn/Yarn.ts

@@ -25,7 +25,6 @@ import { YarnVersion } from './types';
 import fs from 'fs-extra';
 import { paths } from '../../paths';
 import { run, runOutput, RunOptions } from '@backstage/cli-common';
-import { getWorkspacesPatterns } from '@backstage/cli-common';
 
 export class Yarn implements PackageManager {
   constructor(private readonly yarnVersion: YarnVersion) {}
@@ -51,7 +50,10 @@ export class Yarn implements PackageManager {
     const rootPackageJsonPath = paths.resolveTargetRoot('package.json');
     try {
       const pkg = await fs.readJson(rootPackageJsonPath);
-      return getWorkspacesPatterns(pkg);
+      const workspaces = pkg?.workspaces;
+      return Array.isArray(workspaces)
+        ? workspaces
+        : workspaces?.packages ?? [];
     } catch (error) {
       return [];
     }

packages/cli/config/jest.js

@@ -20,7 +20,6 @@ const crypto = require('node:crypto');
 const glob = require('node:util').promisify(require('glob'));
 const { version } = require('../package.json');
 const paths = require('@backstage/cli-common').findPaths(process.cwd());
-const { getWorkspacesPatterns } = require('@backstage/cli-common');
 const {
   getJestEnvironment,
   getJestMajorVersion,
@@ -337,10 +336,11 @@ async function getRootConfig() {
     rejectFrontendNetworkRequests,
   };
 
-  const workspacePatterns = getWorkspacesPatterns(rootPkgJson);
+  const ws = rootPkgJson.workspaces;
+  const workspacePatterns = Array.isArray(ws) ? ws : ws?.packages;
 
   // Check if we're running within a specific monorepo package. In that case just get the single project config.
-  if (workspacePatterns.length === 0 || paths.targetRoot !== paths.targetDir) {
+  if (!workspacePatterns || paths.targetRoot !== paths.targetDir) {
     return getProjectConfig(
       paths.targetDir,
       {