Add core ad blocking capabilities

[CrisBarreiro]

Task/Issue URL: https://app.asana.com/1/137249556945/project/1212227266948491/task/1213078401808051?focus=true

Description

Add core ad blocking capabilities

Steps to test this PR

Feature 1

• Fresh install the app
• Open YouTube.com
• Check logs for Feature not discoverable and Status checker rejected injection, skipping
• Go to feature flag inventory and enable adBlockingExtension.isDiscoverable
• Kill and reopen the app
• Check logs for Feature not operational and Status checker rejected injection, skipping
• Go to feature flag inventory and enable adBlockingExtension
• Kill and reopen the app
• Check logs for Empty payload, skipping
• Browse through a few videos and check ads are shown

Feature 2

• Apply Patch 1: Update RC URL
• Fresh install the app
• Open YouTube.com
• Check logs for Feature not discoverable and Status checker rejected injection, skipping
• Go to feature flag inventory and enable adBlockingExtension, and adBlockingExtension.isDiscoverable
• Kill and reopen the app
• Check logs for Injecting script
• Browse through a few videos and check ads are not shown

Patches

Patch 1: Update RC URL

Subject: [PATCH] Update privacy-config URL
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Index: privacy-config/privacy-config-api/src/main/java/com/duckduckgo/privacy/config/api/PrivacyFeatureName.kt
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/privacy-config/privacy-config-api/src/main/java/com/duckduckgo/privacy/config/api/PrivacyFeatureName.kt b/privacy-config/privacy-config-api/src/main/java/com/duckduckgo/privacy/config/api/PrivacyFeatureName.kt
--- a/privacy-config/privacy-config-api/src/main/java/com/duckduckgo/privacy/config/api/PrivacyFeatureName.kt	(revision ca28c5a412606fefb8bcee8532f901d9fe30b55c)
+++ b/privacy-config/privacy-config-api/src/main/java/com/duckduckgo/privacy/config/api/PrivacyFeatureName.kt	(date 1779203719053)
@@ -29,4 +29,4 @@
     TrackingParametersFeatureName("trackingParameters"),
 }
 
-const val PRIVACY_REMOTE_CONFIG_URL = "https://staticcdn.duckduckgo.com/trackerblocking/config/v5/android-config.json"
+const val PRIVACY_REMOTE_CONFIG_URL = "https://duckduckgo.github.io/privacy-configuration/pr-5175/v4/android-config.json"

UI changes

n/a

---

Note

Medium Risk
Injects dynamically-sourced JavaScript into WebView on page start; mistakes could impact page behavior/performance or unintentionally run on the wrong domains, though it’s gated by feature toggles and domain checks.

Overview
Adds a new JsInjectorPlugin that, on onPageStarted, conditionally injects ad-blocking “scriptlets” into YouTube pages (youtube.com / youtube-nocookie.com and subdomains) via evaluateJavascript.

Introduces a AdBlockingStatusChecker gate (kill-switch + contingency-mode toggle) and extends AdBlockingExtensionRepository with a scriptletsFlow() so the injector can use the latest stored scriptlets, plus unit tests covering gating, domain matching, ordering, and update behavior.

^{Reviewed by Cursor Bugbot for commit ca5bcf7. Bugbot is set up for automated code reviews on this repo. Configure here.}

[CrisBarreiro]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Add settings infra for ad blocking #8660
• Add core ad blocking capabilities #8622 👈 (View in Graphite)
• Implement scriptlet download and storage #8557
• develop

This stack of pull requests is managed by Graphite. Learn more about stacking.

[Copilot]

Pull request overview

This PR introduces the core plumbing to inject “ad blocking extension” scriptlets into pages (currently targeting YouTube domains), sourcing the scriptlet payload from the local Room store and gating injection behind feature toggles.

Changes:

• Add AdBlockingExtensionJsInjectorPlugin to build and inject a combined JS payload on onPageStarted.
• Extend AdBlockingExtensionRepository with a scriptletsFlow() API and introduce a Scriptlet model.
• Add tests for injection gating (feature flags, domain matching) and payload behavior (sorting, updates); add AndroidX.core.ktx dependency for toUri.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
ad-blocking/ad-blocking-impl/src/main/java/com/duckduckgo/adblocking/impl/AdBlockingExtensionJsInjectorPlugin.kt	New JS injector plugin that gates and injects scriptlets on page start for configured domains.
ad-blocking/ad-blocking-impl/src/main/java/com/duckduckgo/adblocking/impl/AdBlockingExtensionRepository.kt	Adds a flow-based API to observe scriptlets and maps DB entities into Scriptlet.
ad-blocking/ad-blocking-impl/src/main/java/com/duckduckgo/adblocking/impl/Scriptlet.kt	Introduces a Scriptlet data model (name + JS content).
ad-blocking/ad-blocking-impl/src/test/java/com/duckduckgo/adblocking/impl/AdBlockingExtensionJsInjectorPluginTest.kt	Adds unit tests covering injection conditions and payload composition.
ad-blocking/ad-blocking-impl/build.gradle	Adds AndroidX.core.ktx dependency required by the plugin.

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[cmonfortep]

LGTM

I need to test on a real device, but not blocker. When testing this on the emulators I noticed few seconds of loading on every video, I don't remember seeing that when I did the hackphase. if we see this happening, when we are doing pixels, we should check if we have something we can use to track this.

[cmonfortep]

is this expected to be local list or provided from the remote config?

[CrisBarreiro]

Yes, expected to be local. Discussed over zoom

[cmonfortep]

Approved