cli: disable feature detection for backend builds

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

.changeset/neat-geckos-end.md

@@ -0,0 +1,5 @@
+---
+'@backstage/cli': patch
+---
+
+Tweaked the new package feature detection to not be active when building backend packages.

packages/cli/src/commands/buildWorkspace.ts

@@ -29,5 +29,6 @@ export default async (dir: string, packages: string[], options: Options) => {
   await createDistWorkspace(packages, {
     targetDir: dir,
     alwaysYarnPack: options.alwaysYarnPack,
+    enableFeatureDetection: true,
   });
 };

packages/cli/src/commands/pack.ts

@@ -21,6 +21,7 @@ import {
 import { paths } from '../lib/paths';
 import fs from 'fs-extra';
 import { publishPreflightCheck } from '../lib/publishing';
+import { createTypeDistProject } from '../lib/typeDistProject';
 
 export const pre = async () => {
   publishPreflightCheck({
@@ -28,7 +29,10 @@ export const pre = async () => {
     packageJson: await fs.readJson(paths.resolveTarget('package.json')),
   });
 
-  await productionPack({ packageDir: paths.targetDir });
+  await productionPack({
+    packageDir: paths.targetDir,
+    featureDetectionProject: await createTypeDistProject(),
+  });
 };
 
 export const post = async () => {

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

@@ -105,6 +105,12 @@ type Options = {
    */
   alwaysYarnPack?: boolean;
 
+  /**
+   * If set to true, the TypeScript feature detection will be enabled, which
+   * annotates the package exports field with the `backstage` export type.
+   */
+  enableFeatureDetection?: boolean;
+
   /**
    * If set to true, the generated code will be minified.
    */
@@ -237,6 +243,7 @@ export async function createDistWorkspace(
     targetDir,
     targets,
     Boolean(options.alwaysYarnPack),
+    Boolean(options.enableFeatureDetection),
   );
 
   const files: FileEntry[] = options.files ?? ['yarn.lock', 'package.json'];
@@ -280,6 +287,7 @@ async function moveToDistWorkspace(
   workspaceDir: string,
   localPackages: PackageGraphNode[],
   alwaysYarnPack: boolean,
+  enableFeatureDetection: boolean,
 ): Promise<void> {
   const [fastPackPackages, slowPackPackages] = partition(
     localPackages,
@@ -288,8 +296,10 @@ async function moveToDistWorkspace(
       FAST_PACK_SCRIPTS.includes(pkg.packageJson.scripts?.prepack),
   );
 
-  const tsMorphProject =
-    fastPackPackages.length > 0 ? await createTypeDistProject() : undefined;
+  const featureDetectionProject =
+    fastPackPackages.length > 0 && enableFeatureDetection
+      ? await createTypeDistProject()
+      : undefined;
 
   // New an improved flow where we avoid calling `yarn pack`
   await Promise.all(
@@ -301,7 +311,7 @@ async function moveToDistWorkspace(
       await productionPack({
         packageDir: target.dir,
         targetDir: absoluteOutputPath,
-        project: tsMorphProject,
+        featureDetectionProject,
       });
     }),
   );

packages/cli/src/lib/packager/productionPack.ts

@@ -19,10 +19,7 @@ import npmPackList from 'npm-packlist';
 import { resolve as resolvePath, posix as posixPath } from 'path';
 import { BackstagePackageJson } from '@backstage/cli-node';
 import { readEntryPoints } from '../entryPoints';
-import {
-  createTypeDistProject,
-  getEntryPointDefaultFeatureType,
-} from '../typeDistProject';
+import { getEntryPointDefaultFeatureType } from '../typeDistProject';
 import { Project } from 'ts-morph';
 
 const PKG_PATH = 'package.json';
@@ -35,9 +32,9 @@ interface ProductionPackOptions {
   packageDir: string;
   targetDir?: string;
   /**
-   * A ts-morph project to share across packages
+   * Enables package feature detection using this TS-morph project.
    */
-  project?: Project;
+  featureDetectionProject?: Project;
 }
 
 export async function productionPack(options: ProductionPackOptions) {
@@ -55,7 +52,7 @@ export async function productionPack(options: ProductionPackOptions) {
   const writeCompatibilityEntryPoints = await prepareExportsEntryPoints(
     pkg,
     packageDir,
-    options.project,
+    options.featureDetectionProject,
   );
 
   // TODO(Rugvip): Once exports are rolled out more broadly we should deprecate and remove this behavior
@@ -144,7 +141,7 @@ const EXPORT_MAP = {
 async function prepareExportsEntryPoints(
   pkg: BackstagePackageJson,
   packageDir: string,
-  commonProject?: Project,
+  featureDetectionProject?: Project,
 ) {
   const distPath = resolvePath(packageDir, 'dist');
   if (!(await fs.pathExists(distPath))) {
@@ -158,7 +155,6 @@ async function prepareExportsEntryPoints(
   >();
 
   const entryPoints = readEntryPoints(pkg);
-  const project = commonProject || (await createTypeDistProject());
 
   for (const entryPoint of entryPoints) {
     if (!SCRIPT_EXTS.includes(entryPoint.ext)) {
@@ -177,14 +173,14 @@ async function prepareExportsEntryPoints(
 
     exp.default = exp.require ?? exp.import;
 
-    // Find the default export type for the entry point
-    if (exp.types) {
+    // Find the default export type for the entry point, if feature detection is active
+    if (exp.types && featureDetectionProject) {
       const defaultFeatureType =
         pkg.backstage?.role &&
         getEntryPointDefaultFeatureType(
           pkg.backstage?.role,
           packageDir,
-          project,
+          featureDetectionProject,
           exp.types,
         );