fix(@angular-devkit/build-angular): separate initial total size in build output

```
Initial Chunk Files                      | Names                |      Size
main-es5.6f60fbc22c7e19b5d179.js         | main                 | 154.89 kB
main-es2015.6f60fbc22c7e19b5d179.js      | main                 | 135.87 kB
polyfills-es5.0351d1276e488726c8dc.js    | polyfills-es5        | 129.34 kB
polyfills-es2015.904e51532a46df6b991c.js | polyfills            |  36.12 kB
scripts.b7f93721b30caf483f97.js          | scripts              |   3.45 kB
runtime-es2015.76bfea807ccb0a24e182.js   | runtime              |   1.45 kB
runtime-es5.76bfea807ccb0a24e182.js      | runtime              |   1.45 kB
styles.3ff695c00d717f2d2a11.css          | styles               |   0 bytes

                                         | Initial ES5 Total    | 289.13 kB
                                         | Initial ES2015 Total | 176.88 kB
```

Closes #19330

packages/angular_devkit/build_angular/src/browser/index.ts

@@ -69,6 +69,7 @@ import { NgBuildAnalyticsPlugin } from '../webpack/plugins/analytics';
 import { markAsyncChunksNonInitial } from '../webpack/utils/async-chunks';
 import {
   BundleStats,
+  ChunkType,
   generateBundleStats,
   statsErrorsToString,
   statsHasErrors,
@@ -592,11 +593,11 @@ export function buildWebpackBrowser(
                   const chunk = webpackStats.chunks?.find((chunk) => chunk.id.toString() === result.name);
 
                   if (result.original) {
-                    bundleInfoStats.push(generateBundleInfoStats(result.original, chunk));
+                    bundleInfoStats.push(generateBundleInfoStats(result.original, chunk, 'modern'));
                   }
 
                   if (result.downlevel) {
-                    bundleInfoStats.push(generateBundleInfoStats(result.downlevel, chunk));
+                    bundleInfoStats.push(generateBundleInfoStats(result.downlevel, chunk, 'legacy'));
                   }
                 }
 
@@ -605,7 +606,7 @@ export function buildWebpackBrowser(
                 ) || [];
                 for (const chunk of unprocessedChunks) {
                   const asset = webpackStats.assets?.find(a => a.name === chunk.files[0]);
-                  bundleInfoStats.push(generateBundleStats({ ...chunk, size: asset?.size }, true));
+                  bundleInfoStats.push(generateBundleStats({ ...chunk, size: asset?.size }));
                 }
 
                 // Check for budget errors and display them to the user.
@@ -773,6 +774,7 @@ type ArrayElement<A> = A extends ReadonlyArray<infer T> ? T : never;
 function generateBundleInfoStats(
   bundle: ProcessBundleFile,
   chunk: ArrayElement<webpack.Stats.ToJsonOutput['chunks']> | undefined,
+  chunkType: ChunkType,
 ): BundleStats {
   return generateBundleStats(
     {
@@ -782,8 +784,8 @@ function generateBundleInfoStats(
       entry: !!chunk?.names.includes('runtime'),
       initial: !!chunk?.initial,
       rendered: true,
+      chunkType,
     },
-    true,
   );
 }
 export default createBuilder<json.JsonObject & BrowserBuilderSchema>(buildWebpackBrowser);

packages/angular_devkit/build_angular/src/webpack/utils/stats.ts

@@ -29,9 +29,12 @@ export function formatSize(size: number): string {
 
 export type BundleStatsData = [files: string, names: string, size: number | string];
 
+export type ChunkType = 'modern' | 'legacy' | 'unknown';
+
 export interface BundleStats {
   initial: boolean;
   stats: BundleStatsData;
+  chunkType: ChunkType;
 };
 
 export function generateBundleStats(
@@ -42,15 +45,17 @@ export function generateBundleStats(
     entry: boolean;
     initial: boolean;
     rendered?: boolean;
+    chunkType?: ChunkType,
   },
-  colors: boolean,
 ): BundleStats {
   const size = typeof info.size === 'number' ? info.size : '-';
   const files = info.files.filter(f => !f.endsWith('.map')).map(f => path.basename(f)).join(', ');
   const names = info.names?.length ? info.names.join(', ') : '-';
   const initial = !!(info.entry || info.initial);
+  const chunkType = info.chunkType || 'unknown';
 
   return {
+    chunkType,
     initial,
     stats: [files, names, size],
   }
@@ -65,9 +70,11 @@ function generateBuildStatsTable(data: BundleStats[], colors: boolean, showTotal
   const changedEntryChunksStats: BundleStatsData[] = [];
   const changedLazyChunksStats: BundleStatsData[] = [];
 
-  let initialTotalSize = 0;
+  let initialModernTotalSize = 0;
+  let initialLegacyTotalSize = 0;
+  let modernFileSuffix: string | undefined;
 
-  for (const { initial, stats } of data) {
+  for (const { initial, stats, chunkType } of data) {
     const [files, names, size] = stats;
 
     const data: BundleStatsData = [
@@ -80,9 +87,23 @@ function generateBuildStatsTable(data: BundleStats[], colors: boolean, showTotal
       changedEntryChunksStats.push(data);
 
       if (typeof size === 'number') {
-        initialTotalSize += size;
+        switch (chunkType) {
+          case 'modern':
+            initialModernTotalSize += size;
+            if (!modernFileSuffix) {
+              const match = files.match(/-(es20\d{2}|esnext)/);
+              modernFileSuffix = match?.[1].toString().toUpperCase();
+            }
+            break;
+          case 'legacy':
+            initialLegacyTotalSize += size;
+            break;
+          default:
+            initialModernTotalSize += size;
+            initialLegacyTotalSize += size;
+            break;
+        }
       }
-
     } else {
       changedLazyChunksStats.push(data);
     }
@@ -99,7 +120,14 @@ function generateBuildStatsTable(data: BundleStats[], colors: boolean, showTotal
 
     if (showTotalSize) {
       bundleInfo.push([]);
-      bundleInfo.push([' ', 'Initial Total', formatSize(initialTotalSize)].map(bold));
+      if (initialModernTotalSize === initialLegacyTotalSize) {
+        bundleInfo.push([' ', 'Initial Total', formatSize(initialModernTotalSize)].map(bold));
+      } else {
+        bundleInfo.push(
+          [' ', 'Initial ES5 Total', formatSize(initialLegacyTotalSize)].map(bold),
+          [' ', `Initial ${modernFileSuffix} Total`, formatSize(initialModernTotalSize)].map(bold),
+        );
+      }
     }
   }
 
@@ -142,7 +170,7 @@ function statsToString(json: any, statsConfig: any, bundleState?: BundleStats[])
 
       const assets = json.assets.filter((asset: any) => chunk.files.includes(asset.name));
       const summedSize = assets.filter((asset: any) => !asset.name.endsWith(".map")).reduce((total: number, asset: any) => { return total + asset.size }, 0);
-      changedChunksStats.push(generateBundleStats({ ...chunk, size: summedSize }, colors));
+      changedChunksStats.push(generateBundleStats({ ...chunk, size: summedSize }));
     }
     unchangedChunkNumber = json.chunks.length - changedChunksStats.length;
   }

tests/legacy-cli/e2e/tests/basic/build.ts

@@ -19,10 +19,18 @@ export default async function() {
     'IE 11',
   );
   // Production build
-  const { stderr: stderrProgress } = await ng('build', '--prod', '--progress');
+  const { stderr: stderrProgress, stdout } = await ng('build', '--prod', '--progress');
   await expectFileToMatch('dist/test-project/index.html', /main-es5\.[a-zA-Z0-9]{20}\.js/);
   await expectFileToMatch('dist/test-project/index.html', /main-es2015\.[a-zA-Z0-9]{20}\.js/);
 
+  if (!stdout.includes('Initial ES5 Total')) {
+    throw new Error(`Expected stdout not to contain 'Initial ES5 Total' but it did.\n${stdout}`);
+  }
+
+  if (!stdout.includes('Initial ES2015 Total')) {
+    throw new Error(`Expected stdout not to contain 'Initial ES2015 Total' but it did.\n${stdout}`);
+  }
+
   const logs: string[] = [
     'Browser application bundle generation complete',
     'ES5 bundle generation complete',