perf(@angular/build): overlap library asset resolution and deduplicate output mkdir calls

- Start `buildState.collectAssets(options, modifiedFiles)` before `compileLibrary` so asset globbing overlaps with TypeScript/Angular compilation, Rolldown bundling, and manifest generation.
- Execute `deleteFilesFromDisk` and `emitFilesToDisk` concurrently via `Promise.all` since deleted and emitted paths are disjoint.
- Cache ancestor directory promises created by `mkdir(..., { recursive: true })` in `emitFilesToDisk` so parent directories (such as `outputPath`) do not incur redundant `mkdir` syscalls when subdirectories (`fesm2022`, `types`) are created first.
- Return early when `result.hasErrors` is true before adding `bundleOutput.warnings` so secondary bundler warnings are not logged alongside compilation errors.
- Include `options.packageJsonPath` in the error message when `verifyAllowedDependencies` fails.

Author: alan-agius4

packages/angular/build/src/builders/library/pipeline/build-action.ts

@@ -71,6 +71,13 @@ export async function buildAction(actionContext: BuildActionContext): Promise<Ex
       return result;
     }
 
+    const collectedAssetsPromise =
+      actionContext.collectedAssets ?? buildState.collectAssets(options, modifiedFiles);
+    if (collectedAssetsPromise instanceof Promise) {
+      // Prevent unhandled promise rejections if compilation or bundling returns early.
+      collectedAssetsPromise.catch(() => {});
+    }
+
     const filesToEmit: OutputFile[] = [];
 
     if (shouldCompileEntryPoints) {
@@ -127,10 +134,10 @@ export async function buildAction(actionContext: BuildActionContext): Promise<Ex
         return result;
       }
 
-      result.addWarnings(bundleOutput.warnings);
       if (result.hasErrors) {
         return result;
       }
+      result.addWarnings(bundleOutput.warnings);
 
       filesToEmit.push(...bundleOutput.filesToEmit);
       buildState.recordBundleOutput(bundleOutput.bundleResults);
@@ -151,19 +158,17 @@ export async function buildAction(actionContext: BuildActionContext): Promise<Ex
       filesToEmit.push(...manifestFiles);
     }
 
-    const collectedAssets =
-      actionContext.collectedAssets ?? (await buildState.collectAssets(options, modifiedFiles));
+    const collectedAssets = await collectedAssetsPromise;
     filesToEmit.push(...collectedAssets.filesToEmit);
 
-    await emitFilesToDisk(filesToEmit, (file) => path.posix.join(options.outputPath, file.path));
-
     const filesToDelete = buildState.recordEmittedOutputs(collectedAssets, manifestFiles);
 
-    if (filesToDelete.size) {
-      await deleteFilesFromDisk(
+    await Promise.all([
+      deleteFilesFromDisk(
         Array.from(filesToDelete, (file) => path.posix.join(options.outputPath, file)),
-      );
-    }
+      ),
+      emitFilesToDisk(filesToEmit, (file) => path.posix.join(options.outputPath, file.path)),
+    ]);
   } catch (error) {
     assertIsError(error);
     result.addError(error.message);
@@ -184,7 +189,7 @@ function verifyAllowedDependencies(
   options: NormalizedLibraryOptions,
   result: ExecutionResult,
 ): boolean {
-  const { packageJson, allowedNonPeerDependencies } = options;
+  const { packageJson, packageJsonPath, allowedNonPeerDependencies } = options;
   const dependencies = {
     ...(packageJson.dependencies ?? {}),
     ...(packageJson.optionalDependencies ?? {}),
@@ -195,7 +200,7 @@ function verifyAllowedDependencies(
     if (!allowedNonPeerDependencies.some((regex) => regex.test(dep))) {
       result.addError(
         `Dependency '${dep}' must be explicitly allowed using the 'allowedNonPeerDependencies' option, ` +
-          `or moved to 'peerDependencies' in 'package.json'.`,
+          `or moved to 'peerDependencies' in '${packageJsonPath}'.`,
       );
       isValid = false;
     }

packages/angular/build/src/builders/library/tests/behavior/build_spec.ts

@@ -92,7 +92,7 @@ describeLibraryBuilder(executeLibraryBuilder, LIBRARY_BUILDER_INFO, (harness) =>
 
       const { result, logs } = await harness.executeOnce();
       expect(result?.success).toBeTrue();
-      expect(logs.some((l) => l.level === 'warn')).toBeFalse();
+      expect(logs).not.toContain(jasmine.objectContaining({ level: 'warn' }));
     });
 
     it('should preserve JSDoc comments in .d.ts and annotation comments in .mjs bundles', async () => {
@@ -210,10 +210,13 @@ describeLibraryBuilder(executeLibraryBuilder, LIBRARY_BUILDER_INFO, (harness) =>
       );
     });
 
-    it('should log failure on build error', async () => {
+    it('should log failure on build error without secondary bundler warnings', async () => {
       await harness.writeFile(
         'projects/lib/src/public-api.ts',
-        `export const title: number = 'invalid type';`,
+        `
+        export const title: number = 'invalid type';
+        export function runDynamic(code: string) { return eval(code); }
+        `,
       );
 
       harness.useTarget('build', {
@@ -236,6 +239,7 @@ describeLibraryBuilder(executeLibraryBuilder, LIBRARY_BUILDER_INFO, (harness) =>
           ),
         }),
       );
+      expect(logs).not.toContain(jasmine.objectContaining({ level: 'warn' }));
       expect(logs).not.toContain(
         jasmine.objectContaining({
           message: jasmine.stringMatching(/Output location:/),

packages/angular/build/src/builders/library/tests/options/allowed-non-peer-dependencies_spec.ts

@@ -29,7 +29,9 @@ describeLibraryBuilder(executeLibraryBuilder, LIBRARY_BUILDER_INFO, (harness) =>
       expect(logs).toContain(
         jasmine.objectContaining({
           level: 'error',
-          message: jasmine.stringMatching(/lodash-es.*allowedNonPeerDependencies/),
+          message: jasmine.stringMatching(
+            /lodash-es.*allowedNonPeerDependencies.*projects\/lib\/package\.json/,
+          ),
         }),
       );
     });

packages/angular/build/src/utils/disk-files.ts

@@ -50,7 +50,13 @@ export async function emitFilesToDisk<T extends EmittableFile = EmittableFile>(
       let mkdirPromise = directoryCreationPromises.get(fileBasePath);
       if (!mkdirPromise) {
         mkdirPromise = mkdir(fileBasePath, { recursive: true });
-        directoryCreationPromises.set(fileBasePath, mkdirPromise);
+        for (
+          let currentDir = fileBasePath;
+          !directoryCreationPromises.has(currentDir);
+          currentDir = dirname(currentDir)
+        ) {
+          directoryCreationPromises.set(currentDir, mkdirPromise);
+        }
       }
       await mkdirPromise;
     }

packages/angular/build/src/utils/disk-files_spec.ts

@@ -39,6 +39,8 @@ describe('disk-files', () => {
           contents: new TextEncoder().encode('mem-1'),
         },
         { origin: 'memory', path: 'nested/a/mem2.txt', contents: 'mem-2' },
+        { origin: 'memory', path: 'nested/parent.txt', contents: 'parent-mem' },
+        { origin: 'memory', path: 'root.txt', contents: 'root-mem' },
         { origin: 'disk', path: 'nested/b/disk1.txt', source: sourceFile },
         { origin: 'disk', path: 'nested/c/disk2.txt', source: sourceFile },
         { origin: 'memory', path: 'skipped/file.txt', contents: 'should-not-exist' },
@@ -51,6 +53,8 @@ describe('disk-files', () => {
 
       expect(await readFile(join(outDir, 'nested/a/mem1.txt'), 'utf-8')).toBe('mem-1');
       expect(await readFile(join(outDir, 'nested/a/mem2.txt'), 'utf-8')).toBe('mem-2');
+      expect(await readFile(join(outDir, 'nested/parent.txt'), 'utf-8')).toBe('parent-mem');
+      expect(await readFile(join(outDir, 'root.txt'), 'utf-8')).toBe('root-mem');
       expect(await readFile(join(outDir, 'nested/b/disk1.txt'), 'utf-8')).toBe('from-disk');
       expect(await readFile(join(outDir, 'nested/c/disk2.txt'), 'utf-8')).toBe('from-disk');
       expect(existsSync(join(outDir, 'skipped/file.txt'))).toBeFalse();