fix(android): Prevent repeated scroll target logging by updating scroll state

CHANGELOG.md

@@ -5,6 +5,8 @@
 ### Fixes
 
 - Allow multiple UncaughtExceptionHandlerIntegrations to be active at the same time ([#4462](https://github.com/getsentry/sentry-java/pull/4462))
+- Prevent repeated scroll target determination during a single scroll gesture ([#4557](https://github.com/getsentry/sentry-java/pull/4557))
+  - This should reduce the number of ANRs seen in `SentryGestureListener`
 
 ## 8.17.0
 

sentry-android-core/src/main/java/io/sentry/android/core/internal/gestures/SentryGestureListener.java

@@ -139,6 +139,7 @@ public boolean onScroll(
         options
             .getLogger()
             .log(SentryLevel.DEBUG, "Unable to find scroll target. No breadcrumb captured.");
+        scrollState.type = GestureType.Scroll;
         return false;
       } else {
         options

sentry-android-core/src/test/java/io/sentry/android/core/internal/gestures/SentryGestureListenerScrollTest.kt

@@ -11,11 +11,13 @@ import android.widget.AbsListView
 import android.widget.ListAdapter
 import androidx.core.view.ScrollingView
 import io.sentry.Breadcrumb
+import io.sentry.ILogger
 import io.sentry.IScope
 import io.sentry.IScopes
 import io.sentry.PropagationContext
 import io.sentry.Scope
 import io.sentry.ScopeCallback
+import io.sentry.SentryLevel
 import io.sentry.SentryLevel.INFO
 import io.sentry.android.core.SentryAndroidOptions
 import kotlin.test.Test
@@ -28,6 +30,7 @@ import org.mockito.kotlin.doAnswer
 import org.mockito.kotlin.inOrder
 import org.mockito.kotlin.mock
 import org.mockito.kotlin.never
+import org.mockito.kotlin.times
 import org.mockito.kotlin.verify
 import org.mockito.kotlin.verifyNoMoreInteractions
 import org.mockito.kotlin.whenever
@@ -56,7 +59,7 @@ class SentryGestureListenerScrollTest {
     val directions = setOf("up", "down", "left", "right")
 
     internal inline fun <reified T : View> getSut(
-      resourceName: String = "test_scroll_view",
+      resourceName: String? = "test_scroll_view",
       touchWithinBounds: Boolean = true,
       direction: String = "",
     ): SentryGestureListener {
@@ -229,6 +232,22 @@ class SentryGestureListenerScrollTest {
     verify(fixture.scope).propagationContext = any()
   }
 
+  @Test
+  fun `logs error message only once per gesture when no scroll target is found`() {
+    val logger = mock<ILogger>()
+    fixture.options.setLogger(logger)
+    fixture.options.isDebug = true
+    val sut = fixture.getSut<ScrollableListView>(resourceName = null)
+
+    sut.onDown(fixture.firstEvent)
+    fixture.eventsInBetween.forEach { sut.onScroll(fixture.firstEvent, it, 10.0f, 0f) }
+    sut.onUp(fixture.endEvent)
+
+    // Verify that the error message is logged only once during the entire gesture
+    verify(logger, times(1))
+      .log(SentryLevel.DEBUG, "Unable to find scroll target. No breadcrumb captured.")
+  }
+
   internal class ScrollableView : View(mock()), ScrollingView {
     override fun computeVerticalScrollOffset(): Int = 0
 

sentry-android-core/src/test/java/io/sentry/android/core/internal/gestures/ViewHelpers.kt

@@ -67,6 +67,11 @@ internal inline fun <reified T : View> mockView(
   return mockView
 }
 
-internal fun Resources.mockForTarget(target: View, expectedResourceName: String) {
-  whenever(getResourceEntryName(target.id)).thenReturn(expectedResourceName)
+internal fun Resources.mockForTarget(target: View, expectedResourceName: String?) {
+  if (expectedResourceName == null) {
+    whenever(getResourceEntryName(target.id))
+      .thenThrow(Resources.NotFoundException("res not found"))
+  } else {
+    whenever(getResourceEntryName(target.id)).thenReturn(expectedResourceName)
+  }
 }