Pause WebView before updating scripts

Author: CrisBarreiro

app/src/androidTest/java/com/duckduckgo/app/browser/BrowserTabViewModelTest.kt

@@ -7015,6 +7015,32 @@ class BrowserTabViewModelTest {
             assertEquals(1, fakeAddDocumentStartJavaScriptPlugins.otherPlugin.countInitted)
         }
 
+    @Test
+    fun whenPrivacyProtectionsUpdatedAndPauseWebViewBeforeUpdatingScriptEnabledThenWebViewPausedBeforeAddingScript() =
+        runTest {
+            fakeAndroidConfigBrowserFeature.updateScriptOnPageFinished().setRawStoredState(State(true))
+            fakeAndroidConfigBrowserFeature.pauseWebViewBeforeUpdatingScript().setRawStoredState(State(true))
+
+            testee.privacyProtectionsUpdated(mockWebView)
+
+            verify(mockWebView).stopLoading()
+            verify(mockWebView).pauseTimers()
+            verify(mockWebView).resumeTimers()
+        }
+
+    @Test
+    fun whenPrivacyProtectionsUpdatedAndPauseWebViewBeforeUpdatingScriptDisabledThenDoNotWebViewPausedBeforeAddingScript() =
+        runTest {
+            fakeAndroidConfigBrowserFeature.updateScriptOnPageFinished().setRawStoredState(State(true))
+            fakeAndroidConfigBrowserFeature.pauseWebViewBeforeUpdatingScript().setRawStoredState(State(false))
+
+            testee.privacyProtectionsUpdated(mockWebView)
+
+            verify(mockWebView, never()).stopLoading()
+            verify(mockWebView, never()).pauseTimers()
+            verify(mockWebView, never()).resumeTimers()
+        }
+
     @Test
     fun whenPrivacyProtectionsUpdatedAndAndUpdateScriptOnPageFinishedDisabledThenAddDocumentStartJavaScriptOnlyOnCSS() =
         runTest {

app/src/main/java/com/duckduckgo/app/browser/BrowserTabViewModel.kt

@@ -4257,6 +4257,17 @@ class BrowserTabViewModel @Inject constructor(
     }
 
     suspend fun privacyProtectionsUpdated(webView: WebView) {
+        val pauseWebViewBeforeUpdatingScript = withContext(dispatchers.io()) {
+            androidBrowserConfig.pauseWebViewBeforeUpdatingScript().isEnabled()
+        }
+
+        if (pauseWebViewBeforeUpdatingScript) {
+            withContext(dispatchers.main()) {
+                webView.stopLoading()
+                webView.pauseTimers()
+            }
+        }
+
         if (withContext(dispatchers.io()) { !androidBrowserConfig.updateScriptOnPageFinished().isEnabled() }) {
             addDocumentStartJavascriptPlugins
                 .getPlugins()
@@ -4268,6 +4279,10 @@ class BrowserTabViewModel @Inject constructor(
         } else {
             addDocumentStartJavaScript(webView)
         }
+
+        if (pauseWebViewBeforeUpdatingScript) {
+            webView.resumeTimers()
+        }
     }
 
     fun onUserDismissedAutoCompleteInAppMessage() {

app/src/main/java/com/duckduckgo/app/pixels/remoteconfig/AndroidBrowserConfigFeature.kt

@@ -191,4 +191,7 @@ interface AndroidBrowserConfigFeature {
 
     @Toggle.DefaultValue(TRUE)
     fun updateScriptOnPageFinished(): Toggle
+
+    @Toggle.DefaultValue(TRUE)
+    fun pauseWebViewBeforeUpdatingScript(): Toggle
 }