Strip prepare script from internal dependency manifests (#170)

In v1.28.3, scripts were preserved in internal dependency manifests to
support lifecycle hooks like `postinstall` (e.g. Prisma client
generation). However, the `prepare` script is problematic because it
runs during `pnpm install` and typically depends on devDependency
binaries (e.g. `tsdown`, `del-cli`) that are not available in the
isolated output, causing the install to fail.

This strips the `prepare` script from internal dependency manifests
while preserving all other scripts. Documentation has been updated to
explain this behavior.

Fixes #169

Scope: isolate-package
Visibility: user-facing

Author: 0x80

docs/configuration.md

@@ -98,6 +98,15 @@ to preserve all of the other scripts, set it to `["build"]`.
 By default, all scripts are omitted, and the [pickFromScripts](#pickfromscripts)
 configuration overrules this configuration.
 
+::: info Scripts in internal dependencies
+The `pickFromScripts` and `omitFromScripts` options only apply to the target
+package manifest. Internal dependency manifests preserve their scripts by
+default (e.g. for `postinstall` hooks like Prisma client generation), with one
+exception: the `prepare` script is always stripped from internal dependencies
+because it runs during `pnpm install` and typically depends on devDependency
+binaries that are not available in the isolated output.
+:::
+
 ### omitPackageManager
 
 Type: `boolean`, default: `false`

src/lib/manifest/helpers/adapt-internal-package-manifests.test.ts

@@ -95,6 +95,55 @@ describe("adaptInternalPackageManifests", () => {
     });
   });
 
+  it("should strip the prepare script from internal dependency manifests", async () => {
+    const manifest: PackageManifest = {
+      name: "@repo/common",
+      version: "1.0.0",
+      scripts: {
+        prepare: "npm run clean && npm run build",
+        clean: "del-cli dist",
+        build: "tsdown",
+        postinstall: "prisma generate",
+      },
+      dependencies: {
+        ky: "^1.0.0",
+      },
+      devDependencies: {
+        "del-cli": "^7.0.0",
+        tsdown: "^0.20.0",
+      },
+    };
+
+    const packagesRegistry = createRegistry({
+      "@repo/common": {
+        rootRelativeDir: "packages/common",
+        manifest,
+      },
+    });
+
+    await adaptInternalPackageManifests({
+      internalPackageNames: ["@repo/common"],
+      packagesRegistry,
+      isolateDir: "/output",
+      forceNpm: false,
+      workspaceRootDir: "/workspace",
+    });
+
+    expect(writeManifest).toHaveBeenCalledOnce();
+
+    const writtenManifest = writeManifest.mock.calls[0]![1];
+
+    /** prepare should be stripped because it depends on devDependency binaries */
+    expect(writtenManifest.scripts?.prepare).toBeUndefined();
+
+    /** Other scripts should be preserved */
+    expect(writtenManifest.scripts).toEqual({
+      clean: "del-cli dist",
+      build: "tsdown",
+      postinstall: "prisma generate",
+    });
+  });
+
   it("should strip devDependencies from internal dependency manifests", async () => {
     const manifest: PackageManifest = {
       name: "@repo/shared",

src/lib/manifest/helpers/adapt-internal-package-manifests.ts

@@ -34,6 +34,17 @@ export async function adaptInternalPackageManifests({
       /** Dev dependencies are never included for internal deps */
       const strippedManifest = omit(manifest, ["devDependencies"]);
 
+      /**
+       * Strip the `prepare` script because it runs during `pnpm install` and
+       * typically depends on devDependency binaries (e.g. tsdown, del-cli)
+       * which are not available in the isolated output. Other lifecycle
+       * scripts like `postinstall` are preserved because they handle runtime
+       * setup (e.g. Prisma client generation).
+       */
+      if (strippedManifest.scripts) {
+        strippedManifest.scripts = omit(strippedManifest.scripts, ["prepare"]);
+      }
+
       /** Resolve catalog dependencies before adapting internal deps */
       const manifestWithResolvedCatalogs = {
         ...strippedManifest,