refactor(@angular-devkit/build-angular): remove NG_BUILD_PROFILING and DEVKIT_PROFILING logic

Generating a CPU profile using Node.JS `--cpu-prof` or Chrome insector is preferred.

Closes #20336

Author: alan-agius4

lib/bootstrap-local.js

@@ -31,42 +31,6 @@ const compilerOptions = ts.getParsedCommandLineOfConfigFile(
   ts.sys,
 ).options;
 
-// Check if we need to profile this CLI run.
-let profiler = null;
-if (process.env['DEVKIT_PROFILING']) {
-  debugLocal('setup profiling');
-  try {
-    profiler = require('v8-profiler-node8');
-  } catch (err) {
-    throw new Error(
-      `Could not require 'v8-profiler-node8'. You must install it separetely with` +
-        `'npm install v8-profiler-node8 --no-save.\n\nOriginal error:\n\n${err}`,
-    );
-  }
-
-  profiler.startProfiling();
-
-  function exitHandler(options, _err) {
-    if (options.cleanup) {
-      const cpuProfile = profiler.stopProfiling();
-      const profileData = JSON.stringify(cpuProfile);
-      const filePath = path.resolve(process.cwd(), process.env.DEVKIT_PROFILING) + '.cpuprofile';
-
-      debugLocal('saving profiling data');
-      console.log(`Profiling data saved in "${filePath}": ${profileData.length} bytes`);
-      fs.writeFileSync(filePath, profileData);
-    }
-
-    if (options.exit) {
-      process.exit();
-    }
-  }
-
-  process.on('exit', exitHandler.bind(null, { cleanup: true }));
-  process.on('SIGINT', exitHandler.bind(null, { exit: true }));
-  process.on('uncaughtException', exitHandler.bind(null, { exit: true }));
-}
-
 if (process.env['DEVKIT_LONG_STACK_TRACE']) {
   debugLocal('setup long stack trace');
   Error.stackTraceLimit = Infinity;

packages/angular_devkit/build_angular/src/utils/environment-options.ts

@@ -66,10 +66,6 @@ export const allowMangle = isPresent(mangleVariable)
 export const shouldBeautify = debugOptimize.beautify;
 export const allowMinify = debugOptimize.minify;
 
-// Build profiling
-const profilingVariable = process.env['NG_BUILD_PROFILING'];
-export const profilingEnabled = isPresent(profilingVariable) && isEnabled(profilingVariable);
-
 /**
  * Some environments, like CircleCI which use Docker report a number of CPUs by the host and not the count of available.
  * This cause `Error: Call retries were exceeded` errors when trying to use them.

packages/angular_devkit/build_angular/src/webpack/configs/common.ts

@@ -16,12 +16,11 @@ import {
   ContextReplacementPlugin,
   RuleSetRule,
   SourceMapDevToolPlugin,
-  debug,
 } from 'webpack';
 import { SubresourceIntegrityPlugin } from 'webpack-subresource-integrity';
 import { AngularBabelLoaderOptions } from '../../babel/webpack-loader';
 import { WebpackConfigOptions } from '../../utils/build-options';
-import { allowMangle, profilingEnabled } from '../../utils/environment-options';
+import { allowMangle } from '../../utils/environment-options';
 import { loadEsmModule } from '../../utils/load-esm';
 import {
   CommonJsUsageWarnPlugin,
@@ -133,14 +132,6 @@ export async function getCommonConfig(wco: WebpackConfigOptions): Promise<Config
     }
   }
 
-  if (profilingEnabled) {
-    extraPlugins.push(
-      new debug.ProfilingPlugin({
-        outputPath: path.resolve(root, 'chrome-profiler-events.json'),
-      }),
-    );
-  }
-
   if (allowedCommonJsDependencies) {
     // When this is not defined it means the builder doesn't support showing common js usages.
     // When it does it will be an array.