chore(lint): satisfy CI lint and CodeQL in DASH support files

- replace shell-built tar/npm commands with execFileSync arg arrays in
  the fixture generator (CodeQL: uncontrolled shell command)
- give jest stub methods explicit bodies (no-empty-function)
- compact the diagnostic label switches in WebPlayerViewComponent to
  stay under the max-lines budget

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

apps/web-e2e/src/fixtures/dash/generate-fixture.mjs

@@ -26,7 +26,7 @@
  * Usage: node apps/web-e2e/src/fixtures/dash/generate-fixture.mjs
  */
 
-import { execFileSync, execSync } from 'node:child_process';
+import { execFileSync } from 'node:child_process';
 import { chmodSync, mkdtempSync, readdirSync, rmSync } from 'node:fs';
 import { createRequire } from 'node:module';
 import { tmpdir } from 'node:os';
@@ -110,14 +110,17 @@ function resolvePackager() {
 function fetchPackagerViaNpmPack() {
     const workDir = mkdtempSync(join(tmpdir(), 'shaka-packager-'));
     console.log(`Fetching shaka-packager via npm pack into ${workDir} ...`);
-    execSync('npm pack shaka-packager --silent', {
+    execFileSync('npm', ['pack', 'shaka-packager', '--silent'], {
         cwd: workDir,
         stdio: ['ignore', 'ignore', 'inherit'],
     });
     const tarball = readdirSync(workDir).find((name) =>
         name.endsWith('.tgz')
     );
-    execSync(`tar -xzf ${JSON.stringify(tarball)}`, { cwd: workDir });
+    if (!tarball) {
+        throw new Error('npm pack did not produce a shaka-packager tarball.');
+    }
+    execFileSync('tar', ['-xzf', tarball], { cwd: workDir });
 
     const binaryName = {
         darwin: { arm64: 'packager-osx-arm64', x64: 'packager-osx-x64' },

apps/web/src/test-stubs/shaka-player.js

@@ -59,7 +59,9 @@ class MockShakaPlayer {
         return [];
     }
 
-    selectAudioTrack() {}
+    selectAudioTrack() {
+        return undefined;
+    }
 
     getTextTracks() {
         return [];
@@ -79,7 +81,9 @@ MockShakaPlayer.isBrowserSupported = () => true;
 const shaka = {
     Player: MockShakaPlayer,
     polyfill: {
-        installAll() {},
+        installAll() {
+            return undefined;
+        },
     },
     __instances: [],
     __reset() {

libs/ui/playback/src/lib/web-player-view/web-player-view.component.ts

@@ -370,34 +370,24 @@ export class WebPlayerViewComponent {
     }
 
     private formatPlayer(player: PlaybackDiagnostic['player']): string {
-        switch (player) {
-            case 'videojs':
-                return 'Video.js';
-            case 'html5':
-                return 'HTML5';
-            case 'artplayer':
-                return 'ArtPlayer';
-            default:
-                return '';
-        }
+        const labels: Record<string, string> = {
+            videojs: 'Video.js',
+            html5: 'HTML5',
+            artplayer: 'ArtPlayer',
+        };
+        return (player && labels[player]) || '';
     }
 
     private formatDiagnosticSource(
         source: PlaybackDiagnostic['source']
     ): string {
-        switch (source) {
-            case 'hls':
-                return 'HLS.js';
-            case 'mpegts':
-                return 'mpegts.js';
-            case 'native':
-                return 'Native media element';
-            case 'shaka':
-                return 'Shaka Player';
-            case 'source':
-                return 'Stream metadata';
-            default:
-                return source;
-        }
+        const labels: Record<string, string> = {
+            hls: 'HLS.js',
+            mpegts: 'mpegts.js',
+            native: 'Native media element',
+            shaka: 'Shaka Player',
+            source: 'Stream metadata',
+        };
+        return labels[source] ?? source;
     }
 }