fix CosmeticApi.getScriptText() return type. AG-25896

Squashed commit of the following: commit d429f0a Merge: f102f43 3d6c256 Author: Slava Leleka <[email protected]> Date: Thu Nov 30 14:04:05 2023 +0200 Merge branch 'master' into fix/AG-25896 commit f102f43 Author: Vladimir Zhelvis <[email protected]> Date: Fri Nov 24 18:08:27 2023 +0300 fix comment online with Bitbucket commit 00b080b Author: Slava Leleka <[email protected]> Date: Wed Nov 22 17:05:47 2023 +0200 fix CosmeticApi.getScriptText() return type
AdguardTeam · Nov 30, 2023 · 01a9240 · 01a9240
1 parent 3d6c256
commit 01a9240
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Showing 2 changed files with 12 additions and 7 deletions.
diff --git a/packages/tswebextension/src/lib/mv2/background/cosmetic-api.ts b/packages/tswebextension/src/lib/mv2/background/cosmetic-api.ts
@@ -162,11 +162,11 @@ export class CosmeticApi extends CosmeticApiCommon {
      *
      * @param rules Cosmetic rules.
      * @param frameUrl Frame url.
-     * @returns Scripts or undefined.
+     * @returns Script text or empty string if no script rules are passed.
      */
-    public static getScriptText(rules: CosmeticRule[], frameUrl?: string): string | undefined {
+    public static getScriptText(rules: CosmeticRule[], frameUrl?: string): string {
         if (rules.length === 0) {
-            return undefined;
+            return '';
         }
 
         const permittedRules = CosmeticApi.sanitizeScriptRules(rules);
@@ -191,7 +191,7 @@ export class CosmeticApi extends CosmeticApiCommon {
             .join('\n');
 
         if (!scriptText) {
-            return undefined;
+            return '';
         }
 
         return `
@@ -292,9 +292,6 @@ export class CosmeticApi extends CosmeticApiCommon {
         const scriptRules = cosmeticResult.getScriptRules();
 
         let scriptText = CosmeticApi.getScriptText(scriptRules, url);
-        // TODO: fix concatenation of undefined and string because:
-        // undefined + '<stealth script>' === 'undefined<stealth script>'
-        // AG-25896.
         scriptText += stealthApi.getSetDomSignalScript();
 
         if (scriptText) {

diff --git a/packages/tswebextension/test/lib/mv2/background/cosmetic-api.test.ts b/packages/tswebextension/test/lib/mv2/background/cosmetic-api.test.ts
@@ -390,6 +390,14 @@ describe('cosmetic api', () => {
             expect(scriptText?.replace(/\s/g, '')).toStrictEqual(expectScriptText.replace(/\s/g, ''));
         });
 
+        it('no rules -- empty string', () => {
+            const testRules: CosmeticRule[] = [];
+
+            const scriptText = CosmeticApi.getScriptText(testRules);
+
+            expect(scriptText).toStrictEqual('');
+        });
+
         it('allow scriptlets and JS rules from custom filter in all browsers, except FirefoxAMO', () => {
             const CUSTOM_FILTER_ID = 1001;