fix(bazel): speed up d.ts bundling by configuring worker

Speeds up the `d.ts` bundling by configuring it as a Bazel
persistent worker. Also improve logging for the ng packager
rule to make it easier to spot which actions/bundles take
up significant time.

Type bundling will occur for every entry-point so for machines
with rather limited cores/threads, this will be useful to save
NodeJS boot and resolution time.

package.json

@@ -73,6 +73,7 @@
     "@bazel/rollup": "5.4.1",
     "@bazel/runfiles": "5.4.1",
     "@bazel/terser": "5.4.1",
+    "@bazel/worker": "5.4.1",
     "@microsoft/api-extractor": "7.22.2",
     "@rollup/plugin-babel": "^5.3.0",
     "@rollup/plugin-commonjs": "^21.0.0",

packages/bazel/package.json

@@ -30,6 +30,7 @@
   "peerDependencies": {
     "@angular/compiler-cli": "0.0.0-PLACEHOLDER",
     "@bazel/concatjs": "^5.3.0",
+    "@bazel/worker": "^5.3.0",
     "@rollup/plugin-commonjs": "^21.0.0",
     "@rollup/plugin-node-resolve": "^13.0.4",
     "rollup": "^2.56.3",

packages/bazel/src/ng_package/ng_package.bzl

@@ -221,7 +221,7 @@ def _run_rollup(ctx, bundle_name, rollup_config, entry_point, inputs, js_output,
     if stamp and ctx.version_file:
         other_inputs.append(ctx.version_file)
     ctx.actions.run(
-        progress_message = "ng_package: Rollup %s %s" % (bundle_name, ctx.label),
+        progress_message = "ng_package: Rollup %s (%s)" % (bundle_name, entry_point.short_path),
         mnemonic = "AngularPackageRollup",
         inputs = inputs.to_list() + other_inputs,
         outputs = [js_output, map_output],

packages/bazel/src/types_bundle/BUILD.bazel

@@ -10,18 +10,15 @@ ts_library(
         "index.ts",
     ],
     deps = [
+        "@npm//@bazel/worker",
         "@npm//@microsoft/api-extractor",
         "@npm//@types/node",
     ],
 )
 
 nodejs_binary(
     name = "types_bundler",
-    data = [
-        ":lib",
-        "@npm//@bazel/concatjs",
-        "@npm//@microsoft/api-extractor",
-    ],
+    data = [":lib"],
     entry_point = ":index.ts",
     # Disable the linker and rely on patched resolution which works better on Windows
     # and is less prone to race conditions when targets build concurrently.

packages/bazel/src/types_bundle/index.bzl

@@ -28,12 +28,19 @@ def bundle_type_declaration(
         args.add(license_banner_file.path)
         inputs.append(license_banner_file)
 
+    # Pass arguments using a flag-file prefixed with `@`. This is
+    # a requirement for build action arguments in persistent workers.
+    # https://docs.bazel.build/versions/main/creating-workers.html#work-action-requirements.
+    args.use_param_file("@%s", use_always = True)
+    args.set_param_file_format("multiline")
+
     ctx.actions.run(
         mnemonic = "BundlingTypes",
         inputs = depset(inputs, transitive = [types]),
         outputs = [output_file],
         executable = ctx.executable._types_bundler_bin,
         arguments = [args],
+        execution_requirements = {"supports-workers": "1"},
         progress_message = "Bundling types (%s)" % entry_point.short_path,
     )
 

packages/bazel/src/types_bundle/index.ts

@@ -9,7 +9,8 @@
 /// <reference types="node"/>
 /// <reference lib="es2020"/>
 
-import {Extractor, ExtractorConfig, IConfigFile, IExtractorConfigPrepareOptions,} from '@microsoft/api-extractor';
+import {runAsWorker, runWorkerLoop} from '@bazel/worker';
+import {Extractor, ExtractorConfig, ExtractorMessage, IConfigFile, IExtractorConfigPrepareOptions} from '@microsoft/api-extractor';
 import * as fs from 'fs';
 import * as path from 'path';
 
@@ -55,7 +56,8 @@ export async function runMain(
   };
 
   const extractorConfig = ExtractorConfig.prepare(options);
-  const {succeeded} = Extractor.invoke(extractorConfig);
+  const {succeeded} =
+      Extractor.invoke(extractorConfig, {messageCallback: handleApiExtractorMessage});
 
   if (!succeeded) {
     throw new Error('Type bundling failed. See error above.');
@@ -89,12 +91,51 @@ function stripAmdModuleDirectiveComments(content: string): string {
   return content.replace(/^\/\/\/ <amd-module name=.*\/>[\r\n]+/gm, '');
 }
 
-// Entry point
-const [entryPointExecpath, outputExecpath, packageJsonExecpath, licenseBannerExecpath] =
-    process.argv.slice(2);
+/**
+ * Handles logging messages from API extractor.
+ *
+ * Certain info messages should be omitted and other messages should be printed
+ * to stderr to avoid worker protocol conflicts.
+ */
+function handleApiExtractorMessage(msg: ExtractorMessage): void {
+  msg.handled = true;
+
+  if (msg.messageId === 'console-compiler-version-notice' || msg.messageId === 'console-preamble') {
+    return;
+  }
+
+  if (msg.logLevel !== 'verbose' && msg.logLevel !== 'none') {
+    console.error(msg.text);
+  }
+}
 
-runMain({entryPointExecpath, outputExecpath, packageJsonExecpath, licenseBannerExecpath})
-    .catch(e => {
-      console.error(e);
+/** Runs one build using the specified build action command line arguments. */
+async function runOneBuild(args: string[]): Promise<boolean> {
+  const [entryPointExecpath, outputExecpath, packageJsonExecpath, licenseBannerExecpath] = args;
+
+  try {
+    await runMain({entryPointExecpath, outputExecpath, packageJsonExecpath, licenseBannerExecpath});
+    return true;
+  } catch (e) {
+    console.error(e);
+    return false;
+  }
+}
+
+// Entry-point.
+const processArgs = process.argv.slice(2);
+
+if (runAsWorker(processArgs)) {
+  runWorkerLoop(runOneBuild);
+} else {
+  // In non-worker mode we need to manually read the flag file and omit
+  // the leading `@` that is added as part of the worker requirements.
+  const flagFile = processArgs[0].substring(1);
+  const args = fs.readFileSync(flagFile, 'utf8').split('\n');
+
+  runOneBuild(args).then(success => {
+    if (!success) {
       process.exitCode = 1;
-    });
+    }
+  });
+}