fix: bundled dependencies should lead to a Yarn nohoist directive

src/yarn/monorepo.ts

@@ -167,6 +167,7 @@ export class Monorepo extends typescript.TypeScriptProject {
     this.package.addField('private', true);
     this.package.addField('workspaces', {
       packages: this.projects.map((p) => p.workspaceDirectory),
+      ...this.renderNoHoist(),
     });
 
     this.tsconfig?.file.addOverride('include', []);
@@ -183,6 +184,21 @@ export class Monorepo extends typescript.TypeScriptProject {
     });
   }
 
+  /**
+   * Render the 'nohoist' directive
+   *
+   * Bundled dependencies must be nohoist'ed, otherwise NPM silently won't bundle them.
+   *
+   * Renders an object that should be mixed into the `workspaces` object.
+   */
+  private renderNoHoist(): any {
+    const nohoist = this.projects.flatMap(p => p.bundledDeps.flatMap(dep => [
+      `${p.name}/${dep}`,
+      `${p.name}/${dep}/**`,
+    ]));
+    return nohoist.length > 0 ? { nohoist } : undefined;
+  }
+
   /**
    * Hooks into the install dependencies cycle
    */

src/yarn/typescript-workspace.ts

@@ -9,6 +9,7 @@ import { TypeScriptWorkspaceOptions } from './typescript-workspace-options';
  */
 export class TypeScriptWorkspace extends typescript.TypeScriptProject {
   public readonly workspaceDirectory: string;
+  public readonly bundledDeps: string[] = [];
 
   private readonly monorepo: Monorepo;
   private readonly isPrivatePackage: boolean;
@@ -189,6 +190,8 @@ export class TypeScriptWorkspace extends typescript.TypeScriptProject {
     this.addTsconfigDevFix();
     this.addEslintRcFix();
 
+    this.bundledDeps.push(...options.bundledDeps ?? []);
+
     options.parent.register(this);
   }
 

test/cdklabs-monorepo.test.ts

@@ -24,6 +24,33 @@ describe('CdkLabsMonorepo', () => {
     expect(outdir).toMatchSnapshot();
   });
 
+  test('bundled dependencies lead to a nohoist directive', () => {
+    // GIVEN
+    const parent = new yarn.CdkLabsMonorepo({
+      name: 'monorepo',
+      defaultReleaseBranch: 'main',
+    });
+
+    new yarn.TypeScriptWorkspace({
+      parent,
+      name: '@cdklabs/one',
+      // WHEN
+      bundledDeps: ['jsonschema'],
+    });
+
+    // THEN
+    const outdir = Testing.synth(parent);
+
+    expect(outdir['package.json']).toEqual(expect.objectContaining({
+      workspaces: expect.objectContaining({
+        nohoist: [
+          '@cdklabs/one/jsonschema',
+          '@cdklabs/one/jsonschema/**',
+        ],
+      }),
+    }));
+  });
+
   test('workspaces get monorepo repository configuration', () => {
     const testRepository = 'https://github.com/cdklabs/cdklabs-projen-project-types';
     const parent = new yarn.CdkLabsMonorepo({