feat(builders): keep prebuilt entry points out of the TypeScript program

src/tools/esbuild/update-federation-tsconfig.spec.ts

@@ -7,8 +7,8 @@ import type { EntryPoint } from '@softarc/native-federation';
 
 vi.mock('fs');
 
-function entry(fileName: string): EntryPoint {
-  return { fileName, outName: 'out.js' } as EntryPoint;
+function entry(fileName: string, kind: EntryPoint['kind'] = 'source'): EntryPoint {
+  return { fileName, outName: 'out.js', kind };
 }
 
 function written() {
@@ -143,4 +143,32 @@ describe('updateFederationTsConfig', () => {
 
     expect(fs.writeFileSync).not.toHaveBeenCalled();
   });
+
+  // A prebuilt mapping is compiled JS; ngtsc rejects it as a root file, and it does not need
+  // compiling in the first place.
+  it('leaves package entry points out of the program', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockReturnValue('{}');
+
+    updateFederationTsConfig('/ws', 'tsconfig.federation.json', [
+      entry('projects/app/src/bootstrap.ts'),
+      entry('dist/ui/fesm2022/ui.mjs', 'package'),
+    ]);
+
+    expect(written().files).toEqual(['projects/app/src/bootstrap.ts']);
+  });
+
+  it('falls back to the app entry points when every mapping is prebuilt', () => {
+    vi.mocked(fs.existsSync).mockReturnValue(true);
+    vi.mocked(fs.readFileSync).mockReturnValue('{}');
+
+    updateFederationTsConfig(
+      '/ws',
+      'tsconfig.federation.json',
+      [entry('dist/ui/fesm2022/ui.mjs', 'package')],
+      ['projects/app/src/main.ts']
+    );
+
+    expect(written().files).toEqual(['projects/app/src/main.ts']);
+  });
 });

src/tools/esbuild/update-federation-tsconfig.ts

@@ -32,7 +32,12 @@
     return path.relative(tsconfigDir, absolute).replace(/\\/g, '/');
   };
 
-  const resolved = entryPoints.map(ep => toTsConfigRelative(ep.fileName));
+  // A 'package' entry point is already-compiled JS. esbuild loads it through the linker like
+  // any dependency, and putting it in `files` only makes ngtsc reject it as a non-TypeScript
+  // root file.
+  const resolved = entryPoints
+    .filter(ep => ep.kind !== 'package')
+    .map(ep => toTsConfigRelative(ep.fileName));
 
   // A host without exposes or shared mappings has no entry points of its own; the app's
   // main.ts keeps the program from being empty.