From d849865b6fafdf7d7c8eb5b96e7d5fd933105e16 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Thu, 7 Nov 2024 13:22:54 +0100
Subject: [PATCH] cli: improve autocomplete of extra entry points in published
 packages

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .changeset/seven-berries-listen.md            |  5 ++
 .../cli/src/lib/packager/productionPack.ts    | 62 +++++--------------
 2 files changed, 22 insertions(+), 45 deletions(-)
 create mode 100644 .changeset/seven-berries-listen.md

diff --git a/.changeset/seven-berries-listen.md b/.changeset/seven-berries-listen.md
new file mode 100644
index 0000000000..2ab18d9e19
--- /dev/null
+++ b/.changeset/seven-berries-listen.md
@@ -0,0 +1,5 @@
+---
+'@backstage/cli': minor
+---
+
+The package packing now populates `typesVersions` for additional entry points rather than using additional `package.json` files for type resolution. This improves auto completion of separate entry points when consuming published packages.
diff --git a/packages/cli/src/lib/packager/productionPack.ts b/packages/cli/src/lib/packager/productionPack.ts
index c15a7f8b9e..9736e97b8d 100644
--- a/packages/cli/src/lib/packager/productionPack.ts
+++ b/packages/cli/src/lib/packager/productionPack.ts
@@ -49,11 +49,7 @@ export async function productionPack(options: ProductionPackOptions) {
   }
 
   // This mutates pkg to fill in index exports, so call it before applying publishConfig
-  const writeCompatibilityEntryPoints = await prepareExportsEntryPoints(
-    pkg,
-    packageDir,
-    options.featureDetectionProject,
-  );
+  await rewriteEntryPoints(pkg, packageDir, options.featureDetectionProject);
 
   // TODO(Rugvip): Once exports are rolled out more broadly we should deprecate and remove this behavior
   const publishConfig = pkg.publishConfig ?? {};
@@ -63,9 +59,6 @@ export async function productionPack(options: ProductionPackOptions) {
     }
   }
 
-  // For published packages we rely on compatibility entry points rather than this
-  delete pkg.typesVersions;
-
   // We remove the dependencies from package.json of packages that are marked
   // as bundled, so that yarn doesn't try to install them.
   if (pkg.bundled) {
@@ -97,10 +90,6 @@ export async function productionPack(options: ProductionPackOptions) {
   } else {
     await fs.writeJson(pkgPath, pkg, { encoding: 'utf8', spaces: 2 });
   }
-
-  if (writeCompatibilityEntryPoints) {
-    await writeCompatibilityEntryPoints(targetDir ?? packageDir);
-  }
 }
 
 // Reverts the changes made by productionPack when called without a targetDir.
@@ -138,7 +127,7 @@ const EXPORT_MAP = {
  * well as returning a function that creates backwards compatibility
  * entry points for importers that don't support exports.
  */
-async function prepareExportsEntryPoints(
+async function rewriteEntryPoints(
   pkg: BackstagePackageJson,
   packageDir: string,
   featureDetectionProject?: Project,
@@ -150,12 +139,13 @@ async function prepareExportsEntryPoints(
   const distFiles = await fs.readdir(distPath);
   const outputExports = {} as Record<string, string | Record<string, string>>;
 
-  const compatibilityWriters = new Array<
-    (targetDir: string) => Promise<void>
-  >();
-
   const entryPoints = readEntryPoints(pkg);
 
+  // Clear to ensure a clean slate before adding entries back in further down
+  if (pkg.typesVersions) {
+    pkg.typesVersions = { '*': {} };
+  }
+
   for (const entryPoint of entryPoints) {
     if (!SCRIPT_EXTS.includes(entryPoint.ext)) {
       outputExports[entryPoint.mount] = entryPoint.path;
@@ -171,6 +161,16 @@ async function prepareExportsEntryPoints(
       }
     }
 
+    // Our current tooling relies on the typesVersions field rather than export.*.types
+    if (exp.types) {
+      if (!pkg.typesVersions) {
+        pkg.typesVersions = { '*': {} };
+      }
+      pkg.typesVersions['*'][entryPoint.name] = [
+        `dist/${entryPoint.name}.d.ts`,
+      ];
+    }
+
     exp.default = exp.require ?? exp.import;
 
     // Find the default export type for the entry point, if feature detection is active
@@ -192,7 +192,6 @@ async function prepareExportsEntryPoints(
       }
     }
 
-    // This creates a directory with a lone package.json for backwards compatibility
     if (entryPoint.mount === '.') {
       if (exp.default) {
         pkg.main = exp.default;
@@ -203,28 +202,6 @@ async function prepareExportsEntryPoints(
       if (exp.types) {
         pkg.types = exp.types;
       }
-    } else {
-      // This is deferred until after we have created the target directory
-      compatibilityWriters.push(async targetDir => {
-        const entryPointDir = resolvePath(targetDir, entryPoint.name);
-        await fs.ensureDir(entryPointDir);
-        await fs.writeJson(
-          resolvePath(entryPointDir, PKG_PATH),
-          {
-            // Need a temporary name, as sharing the same name causes some typescript issues with caching of packages names
-            // And their defined `types` field.
-            name: `${pkg.name}__${entryPoint.name.toLocaleLowerCase('en-US')}`,
-            version: pkg.version,
-            ...(exp.default ? { main: posixPath.join('..', exp.default) } : {}),
-            ...(exp.import ? { module: posixPath.join('..', exp.import) } : {}),
-            ...(exp.types ? { types: posixPath.join('..', exp.types) } : {}),
-          },
-          { encoding: 'utf8', spaces: 2 },
-        );
-      });
-      if (Array.isArray(pkg.files) && !pkg.files.includes(entryPoint.name)) {
-        pkg.files.push(entryPoint.name);
-      }
     }
 
     if (Object.keys(exp).length > 0) {
@@ -238,10 +215,5 @@ async function prepareExportsEntryPoints(
     pkg.exports['./package.json'] = './package.json';
   }
 
-  if (compatibilityWriters.length > 0) {
-    return async (targetDir: string) => {
-      await Promise.all(compatibilityWriters.map(writer => writer(targetDir)));
-    };
-  }
   return undefined;
 }