AG-42200 reduce bundle size

Squashed commit of the following:

commit 92334ee
Merge: 76e9cc9 7fc93da
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Wed May 14 12:16:05 2025 -0400

    Merge branch 'master' into fix/AG-42200

commit 76e9cc9
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Tue May 13 16:57:38 2025 -0400

    fix indent_level to reduce bundle size

commit 75266af
Author: Slava Leleka <v.leleka@adguard.com>
Date:   Tue May 13 16:57:00 2025 -0400

    minify injections during build

Author: slvvko

rollup.config.js

@@ -151,6 +151,7 @@ const scriptletsConfig = {
                 format: {
                     comments: false,
                     beautify: true,
+                    indent_level: 2,
                 },
             },
         ),

scripts/build-funcs.js

@@ -42,11 +42,11 @@ const getScriptletFunctionsString = async () => {
 
     const scriptletsFunctions = Object.values(scriptletsList);
 
-    const scriptletsStrings = scriptletsFunctions.map((scriptlet) => {
-        const scriptletWithDeps = attachDependencies(scriptlet);
+    const scriptletsStrings = await Promise.all(scriptletsFunctions.map(async (scriptlet) => {
+        const scriptletWithDeps = await attachDependencies(scriptlet);
         const scriptletWithCall = addCall(scriptlet, scriptletWithDeps);
         return wrapInFunc(scriptlet.name, scriptletWithCall);
-    });
+    }));
 
     const scriptletsString = scriptletsStrings.join('\n');
 

scripts/build-redirects.js

@@ -125,7 +125,7 @@ const getRedirectCode = async (source) => {
         throw new Error(`Was unable to find redirect by name: ${source.name}`);
     }
 
-    let result = attachDependencies(redirect);
+    let result = await attachDependencies(redirect);
     result = addCall(redirect, result);
 
     // redirect code for different sources is checked in tests

src/helpers/injector.ts

@@ -1,16 +1,42 @@
+import { minify } from 'terser';
+
 import { type Redirect, type Scriptlet } from '../../types/types';
 import { type Source } from '../scriptlets';
 
 /**
- * Concat dependencies to scriptlet code
+ * Concat dependencies to scriptlet code.
+ *
+ * Dependencies are minified using Terser while preserving their names.
  *
  * @param scriptlet scriptlet or redirect function
  * @returns string view of scriptlet with attached dependencies
  */
-export function attachDependencies(scriptlet: Scriptlet | Redirect): string {
+export async function attachDependencies(scriptlet: Scriptlet | Redirect): Promise<string> {
     const { injections = [] } = scriptlet;
-    return injections.reduce((accum, dep) => {
-        return `${accum}\n${dep.toString()}`;
+
+    // Minify each dependency while preserving its name
+    const minifiedDeps = await Promise.all(injections.map(async (dep) => {
+        try {
+            const depStr = dep.toString();
+            const result = await minify(depStr, {
+                compress: true,
+                mangle: {
+                    // injection functions should be accessible by the same name
+                    // so we preserve their names
+                    keep_fnames: true,
+                },
+            });
+            // Fallback to original if minification fails
+            return result.code || depStr;
+        } catch (e) {
+            // If minification fails, return the original code
+            return dep.toString();
+        }
+    }));
+
+    // Combine the minified dependencies with the scriptlet code
+    return minifiedDeps.reduce((acc: string, depCode: string) => {
+        return `${acc}\n${depCode}`;
     }, scriptlet.toString());
 }