Pull request 1173: AG-38806 $removeparam incorrectly removes parameters from encoded URLs

Squashed commit of the following:

commit cc33faa
Author: Maxim Topciu <[email protected]>
Date:   Thu Jan 23 06:37:14 2025 +0200

    AG-38806 remove packs

commit b517ecf
Merge: 85d0be2 7b84768
Author: Maxim Topciu <[email protected]>
Date:   Thu Jan 23 06:35:53 2025 +0200

    Merge branch 'master' into fix/AG-38806

commit 85d0be2
Author: Maxim Topciu <[email protected]>
Date:   Wed Jan 22 13:28:01 2025 +0200

    AG-38806 build tgz

commit 1521a11
Merge: 1913685 0201caf
Author: Maxim Topciu <[email protected]>
Date:   Wed Jan 22 13:03:19 2025 +0200

    Merge branch 'master' into fix/AG-38806

commit 1913685
Author: Maxim Topciu <[email protected]>
Date:   Mon Jan 20 16:26:25 2025 +0200

    AG-38806 update names

commit 215d94d
Author: Maxim Topciu <[email protected]>
Date:   Mon Jan 20 16:24:28 2025 +0200

    AG-38806 add packages for testing

commit eec1307
Author: Maxim Topciu <[email protected]>
Date:   Mon Jan 20 16:06:20 2025 +0200

    AG-38806 update changelog

commit bdaaf10
Author: Maxim Topciu <[email protected]>
Date:   Mon Jan 20 16:02:40 2025 +0200

    AG-38806 preserve params in encoded URLs for removeparam modifier

Author: maximtop

packages/tsurlfilter/CHANGELOG.md

@@ -25,10 +25,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - URI encoded `$removeparam` value is not removed in MV3 [AdguardBrowserExtension#3014].
 - `$removeparam` fails to match encoded URL params in MV2 [AdguardBrowserExtension#3015].
 - `$popup,third-party` modifiers cause document blocking [AdguardBrowserExtension#3012].
+- `$removeparam` incorrectly removes parameters from encoded URLs [AdguardBrowserExtension#3076].
 - Pattern shortcut extraction from regexp patterns with character classes [AdguardBrowserExtension#2924].
 
 [AdguardBrowserExtension#3014]: https://github.com/AdguardTeam/AdguardBrowserExtension/issues/3014
+[AdguardBrowserExtension#3015]: https://github.com/AdguardTeam/AdguardBrowserExtension/issues/3015
 [AdguardBrowserExtension#3012]: https://github.com/AdguardTeam/AdguardBrowserExtension/issues/3012
+[AdguardBrowserExtension#3076]: https://github.com/AdguardTeam/AdguardBrowserExtension/issues/3076
 [AdguardBrowserExtension#2924]: https://github.com/AdguardTeam/AdguardBrowserExtension/issues/2924
 
 ## [3.0.8] - 2024-11-25

packages/tsurlfilter/src/modifiers/remove-param-modifier.ts

@@ -45,7 +45,9 @@ export class RemoveParamModifier implements IAdvancedModifier {
                 throw new Error('Unsupported option in $removeparam: multiple values are not allowed');
             }
 
-            this.valueRegExp = new RegExp(`((^|&)(${SimpleRegex.escapeRegexSpecials(rawValue)})=[^&#]*)`, 'g');
+            // no need to match "&" in the beginning, because we are splitting by "&"
+            // https://github.com/AdguardTeam/AdguardBrowserExtension/issues/3076
+            this.valueRegExp = new RegExp(`^${SimpleRegex.escapeRegexSpecials(rawValue)}=[^&#]*$`, 'g');
         }
     }
 

packages/tsurlfilter/test/modifiers/advanced-modifier.test.ts

@@ -471,6 +471,22 @@ describe('NetworkRule - removeparam rules', () => {
         expect(modifier.removeParameters(`${comPage}?p0=0`)).toBe(`${comPage}?p0=0`);
         expect(modifier.removeParameters(`${comPage}?p0=0&p1=1`)).toBe(`${comPage}?p0=0&p1=1`);
     });
+
+    // https://github.com/AdguardTeam/AdguardBrowserExtension/issues/3076
+    it('preserves parameters in encoded URLs', () => {
+        const rule = createNetworkRule('$removeparam=utm_campaign', 0);
+        const modifier = rule.getAdvancedModifier() as RemoveParamModifier;
+
+        const encodedUrl = `https://redirect.com/path?url=${encodeURIComponent('https://example.com?utm_source=test&utm_campaign=123')}`;
+
+        // Should preserve the encoded URL intact
+        expect(modifier.removeParameters(encodedUrl)).toBe(encodedUrl);
+
+        // Should only remove top-level utm_campaign
+        const mixedUrl = `https://redirect.com/path?utm_campaign=remove&url=${encodeURIComponent('https://example.com?utm_campaign=keep')}`;
+        expect(modifier.removeParameters(mixedUrl))
+            .toBe(`https://redirect.com/path?url=${encodeURIComponent('https://example.com?utm_campaign=keep')}`);
+    });
 });
 
 describe('NetworkRule - mv3 validity', () => {