test: add interm fix for test that rely on an index.d.ts file (#28884)

At the moment, certain tests relies on resolving the module with an index.d.ts, this root cause might be some implementations are missing from the mocks.

Similar to: 58b4045359

PR Close #28884

packages/compiler-cli/test/test_support.ts

@@ -122,8 +122,15 @@ export function setupBazelTo(tmpDirPath: string) {
   fs.mkdirSync(nodeModulesPath);
   fs.mkdirSync(angularDirectory);
 
-  getAngularPackagesFromRunfiles().forEach(
+  getAngularPackagesFromRunfiles().forEach(({pkgPath, name}) => {
-      ({pkgPath, name}) => { fs.symlinkSync(pkgPath, path.join(angularDirectory, name), 'dir'); });
+    fs.symlinkSync(pkgPath, path.join(angularDirectory, name), 'dir');
+
+    // todo: check why we always need an index.d.ts
+    if (!fs.existsSync(path.join(angularDirectory, name, 'index.d.ts'))) {
+      fs.symlinkSync(
+          path.join(pkgPath, `${name}.d.ts`), path.join(angularDirectory, name, 'index.d.ts'));
+    }
+  });
 
   // Link typescript
   const typeScriptSource = resolveNpmTreeArtifact('npm/node_modules/typescript');

packages/compiler/test/aot/test_util.ts

@@ -591,6 +591,11 @@ function readBazelWrittenFilesFrom(
   }
   try {
     processDirectory(bazelPackageRoot, path.join('/node_modules/@angular', packageName));
+    // todo: check why we always need an index.d.ts
+    if (fs.existsSync(path.join(bazelPackageRoot, `${packageName}.d.ts`))) {
+      const content = fs.readFileSync(path.join(bazelPackageRoot, `${packageName}.d.ts`), 'utf8');
+      map.set(path.join('/node_modules/@angular', packageName, 'index.d.ts'), content);
+    }
   } catch (e) {
     console.error(
         `Consider adding //packages/${packageName} as a data dependency in the BUILD.bazel rule for the failing test`);