Updated create-app to use Yarn 4

Signed-off-by: Andre Wanlin <awanlin@spotify.com>

.changeset/cold-squids-perform.md

@@ -0,0 +1,5 @@
+---
+'@backstage/create-app': patch
+---
+
+Yarn 4 is now the default for `create-app`. Updated `yarn dev` script to use `yarn workspaces foreach`. Removed unused Lerna and Concurrently dependencies.

packages/create-app/src/lib/tasks.test.ts

@@ -227,27 +227,6 @@ describe('tasks', () => {
       );
     });
 
-    it('should error out on incorrect yarn version', async () => {
-      // requires callback implementation to support `promisify` wrapper
-      // https://stackoverflow.com/a/60579617/10044859
-      mockExec.mockImplementation((_command, callback) => {
-        callback(null, { stdout: '3.2.1', stderr: 'standard error' });
-      });
-
-      const appDir = 'projects/dir';
-      await expect(buildAppTask(appDir)).rejects.toThrow(
-        /^@backstage\/create-app requires Yarn v1, found '3\.2\.1'/,
-      );
-      expect(mockChdir).toHaveBeenCalledTimes(1);
-      expect(mockChdir).toHaveBeenNthCalledWith(1, appDir);
-      expect(mockExec).toHaveBeenCalledTimes(1);
-      expect(mockExec).toHaveBeenNthCalledWith(
-        1,
-        'yarn --version',
-        expect.any(Function),
-      );
-    });
-
     it('should fail if project directory does not exist', async () => {
       const appDir = 'projects/missingProject';
       await expect(buildAppTask(appDir)).rejects.toThrow(

packages/create-app/src/lib/tasks.ts

@@ -187,17 +187,6 @@ export async function checkPathExistsTask(path: string) {
 export async function buildAppTask(appDir: string) {
   process.chdir(appDir);
 
-  await Task.forItem('determining', 'yarn version', async () => {
-    const result = await exec('yarn --version');
-    const yarnVersion = result.stdout?.trim();
-
-    if (yarnVersion && !yarnVersion.startsWith('1.')) {
-      throw new Error(
-        `@backstage/create-app requires Yarn v1, found '${yarnVersion}'. You can migrate the project to Yarn 3 after creation using https://backstage.io/docs/tutorials/yarn-migration`,
-      );
-    }
-  });
-
   const runCmd = async (cmd: string) => {
     await Task.forItem('executing', cmd, async () => {
       await exec(cmd).catch(error => {

packages/create-app/templates/default-app/.yarnrc.yml

@@ -0,0 +1,3 @@
+nodeLinker: node-modules
+
+yarnPath: .yarn/releases/yarn-4.4.1.cjs

packages/create-app/templates/default-app/lerna.json

@@ -1,6 +0,0 @@
-{
-  "packages": ["packages/*", "plugins/*"],
-  "npmClient": "yarn",
-  "version": "0.1.0",
-  "$schema": "node_modules/lerna/schemas/lerna-schema.json"
-}

packages/create-app/templates/default-app/package.json.hbs

@@ -6,7 +6,7 @@
     "node": "18 || 20"
   },
   "scripts": {
-    "dev": "concurrently \"yarn start\" \"yarn start-backend\"",
+    "dev": "yarn workspaces foreach -A --include backend --include app --parallel -v -i run start",
     "start": "yarn workspace app start",
     "start-backend": "yarn workspace backend start",
     "build:backend": "yarn workspace backend build",
@@ -35,8 +35,6 @@
     "@backstage/e2e-test-utils": "^{{version '@backstage/e2e-test-utils'}}",
     "@playwright/test": "^1.32.3",
     "@spotify/prettier-config": "^12.0.0",
-    "concurrently": "^8.0.0",
-    "lerna": "^7.3.0",
     "node-gyp": "^10.0.0",
     "prettier": "^2.3.2",
     "typescript": "~5.4.0"
@@ -54,5 +52,6 @@
     "*.{json,md}": [
       "prettier --write"
     ]
-  }
+  },
+  "packageManager": "yarn@4.4.1"
 }

packages/create-app/templates/default-app/packages/app/package.json.hbs

@@ -50,10 +50,10 @@
   "devDependencies": {
     "@backstage/test-utils": "^{{version '@backstage/test-utils'}}",
     "@playwright/test": "^1.32.3",
+    "@testing-library/dom": "^9.0.0",
     "@testing-library/jest-dom": "^6.0.0",
     "@testing-library/react": "^14.0.0",
     "@testing-library/user-event": "^14.0.0",
-    "@testing-library/dom": "^9.0.0",
     "@types/react-dom": "*",
     "cross-env": "^7.0.0"
   },

packages/create-app/templates/default-app/packages/backend/Dockerfile

@@ -11,12 +11,15 @@
 
 FROM node:18-bookworm-slim
 
+# Set Python interpreter for `node-gyp` to use
+ENV PYTHON=/usr/bin/python3
+
 # Install isolate-vm dependencies, these are needed by the @backstage/plugin-scaffolder-backend.
 RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
     --mount=type=cache,target=/var/lib/apt,sharing=locked \
     apt-get update && \
     apt-get install -y --no-install-recommends python3 g++ build-essential && \
-    yarn config set python /usr/bin/python3
+    rm -rf /var/lib/apt/lists/*
 
 # Install sqlite3 dependencies. You can skip this if you don't use sqlite3 in the image,
 # in which case you should also move better-sqlite3 to "devDependencies" in package.json.
@@ -33,6 +36,10 @@ USER node
 # If this occurs, then ensure BuildKit is enabled (`DOCKER_BUILDKIT=1`) so the app dir is correctly created as `node`.
 WORKDIR /app
 
+# Copy files needed by Yarn
+COPY --chown=node:node .yarn ./.yarn
+COPY --chown=node:node .yarnrc.yml ./
+
 # This switches many Node.js dependencies to production mode.
 ENV NODE_ENV=production
 
@@ -43,7 +50,7 @@ COPY --chown=node:node yarn.lock package.json packages/backend/dist/skeleton.tar
 RUN tar xzf skeleton.tar.gz && rm skeleton.tar.gz
 
 RUN --mount=type=cache,target=/home/node/.cache/yarn,sharing=locked,uid=1000,gid=1000 \
-    yarn install --frozen-lockfile --production --network-timeout 300000
+    yarn workspaces focus --all --production
 
 # This will include the examples, if you don't need these simply remove this line
 COPY --chown=node:node examples ./examples