Bugfix: Fix Youtube Internal links when 'Watching on Youtube' from Du…

…ck Player (#3733)

Task/Issue URL: https://app.asana.com/0/1204099484721401/1208930843675395/f
Tech Design URL:
CC:

Description:
Fixes an issue causing Youtube internal links to open Duck Player

DuckDuckGo/DuckPlayer/DuckPlayerNavigationHandler.swift

@@ -936,6 +936,16 @@ extension DuckPlayerNavigationHandler: DuckPlayerNavigationHandling {
             return false
         }
 
+        // Allow Youtube's internal navigation when DuckPlayer is enabled and user is watching on Youtube
+        // This is to prevent DuckPlayer from interfering with Youtube's internal navigation for search and settings
+        // https://app.asana.com/0/1204099484721401/1208930843675395/f
+        if let (destinationVideoID, _) = url.youtubeVideoParams,
+           let (originVideoID, _) = webView.url?.youtubeVideoParams,
+            destinationVideoID == originVideoID,
+            duckPlayerMode == .enabled {
+                return false
+        }
+
         // Redirect to Duck Player if enabled
         if url.isYoutubeWatch && duckPlayerMode == .enabled && !isDuckPlayerRedirect(url: url) {
             redirectToDuckPlayerVideo(url: url, webView: webView)

DuckDuckGoTests/YoutublePlayerNavigationHandlerTests.swift

@@ -582,4 +582,24 @@ class DuckPlayerNavigationHandlerTests: XCTestCase {
         XCTAssertNil(tabNavigator.openedURL, "No new tabs should open")
     }
 
+    @MainActor
+    func testHandleDelegateNavigation_YoutubeWatchURLWithDuckPlayerEnabledAndSameVideoNavigation_ReturnsFalse() async {
+        // Arrange
+        let youtubeURL = URL(string: "https://www.youtube.com/watch?v=abc123")!
+        let youtubeInternalURL = URL(string: "https://www.youtube.com/watch?v=abc123&settings")!
+        let request = URLRequest(url: youtubeURL)
+        let mockFrameInfo = MockFrameInfo(isMainFrame: true)
+        let navigationAction = MockNavigationAction(request: request, targetFrame: mockFrameInfo)
+        playerSettings.mode = .enabled
+        featureFlagger.enabledFeatures = [.duckPlayer, .duckPlayerOpenInNewTab]
+
+        mockWebView.setCurrentURL(youtubeInternalURL)
+
+        // Act
+        let shouldCancel = handler.handleDelegateNavigation(navigationAction: navigationAction, webView: mockWebView)
+
+        // Assert
+        XCTAssertFalse(shouldCancel, "Expected navigation NOT to be cancelled as it's Youtube Internal navigation")
+    }
+
 }