fix(android-nav3): Preserve app context when updating transaction context

Author: 0xadam-brown

sentry-android-navigation3/src/main/kotlin/io/sentry/compose/navigation3/BackStackObserver.kt

@@ -208,7 +208,7 @@ internal class BackStackObserver<T : Any>(
           currentTopRoute.name,
           currentTopRoute.arguments,
         )
-        ?.updateNavigationContext(currentBackStack)
+        ?.updateNavigationContext(scope, currentBackStack)
     } else {
       // Rotate the propagation context.
       scope.withPropagationContext { scope.setPropagationContext(PropagationContext()) }
@@ -255,9 +255,13 @@ internal class BackStackObserver<T : Any>(
    * past what's relevant to a given transaction. This method prevents misassociation by binding
    * proper values to the transaction context instead.
    */
-  private fun ITransaction.updateNavigationContext(backStack: BackStackData<T>) {
-    val appContext = contexts.app ?: App().also { contexts.setApp(it) }
-    appContext.viewNames = listOf(backStack.topRoute.name)
+  private fun ITransaction.updateNavigationContext(scope: IScope, backStack: BackStackData<T>) {
+    if (scopes.options.isEnableScreenTracking) {
+      val appContext = contexts.app ?: io.sentry.protocol.Contexts(scope.contexts).app ?: App()
+
+      appContext.viewNames = listOf(backStack.topRoute.name)
+      contexts.setApp(appContext)
+    }
 
     if (options.captureBackStack && backStack.capturedRoutes.isNotEmpty()) {
       setContext(NAVIGATION_CONTEXT_KEY, backStack.capturedRoutes.toNavigationContext())
@@ -303,6 +307,7 @@ internal class BackStackObserver<T : Any>(
     try {
       body()
     } catch (t: Throwable) {
+      // Nav instrumentation can invoke host code through route translation and scope mutation.
       ExceptionUtils.rethrowIfFatal(t)
       scopes.options.logger.log(
         ERROR,

sentry-android-navigation3/src/test/kotlin/io/sentry/compose/navigation3/BackStackObserverTest.kt

@@ -15,6 +15,7 @@ import io.sentry.SentryTracer
 import io.sentry.TransactionContext
 import io.sentry.TransactionOptions
 import io.sentry.TypeCheckHint
+import io.sentry.protocol.App
 import io.sentry.protocol.TransactionNameSource
 import kotlin.test.Test
 import kotlin.test.assertNull
@@ -230,6 +231,7 @@ class BackStackObserverTest {
 
     assertThat(fixture.scope.screen).isNull()
     assertThat(fixture.scope.contexts.app?.viewNames).isNull()
+    assertThat(fixture.startedTransactions.single().contexts.app?.viewNames).isNull()
   }
 
   @Test
@@ -372,6 +374,31 @@ class BackStackObserverTest {
     assertThat(argumentCalls).doesNotContainKey(home)
   }
 
+  @Test
+  fun `onBackStackChanged resolves top entry arguments once per update`() {
+    val fixture = Fixture()
+    val home = HomeRoute()
+    val profile = ProfileRoute("123")
+    val argumentCalls = mutableMapOf<Any, Int>()
+    val sut =
+      fixture.getSut(
+        argumentsExtractor =
+          RouteArgumentsExtractor { entry ->
+            argumentCalls[entry] = (argumentCalls[entry] ?: 0) + 1
+            when (entry) {
+              is HomeRoute -> mapOf("tab" to entry.id)
+              is ProfileRoute -> mapOf("userId" to entry.userId)
+              else -> emptyMap()
+            }
+          }
+      )
+
+    sut.onBackStackChanged(listOf(home, profile))
+
+    assertThat(argumentCalls[profile]).isEqualTo(1)
+    assertThat(argumentCalls[home]).isEqualTo(1)
+  }
+
   @Test
   fun `onBackStackChanged creates a nav transaction when enabled and no ambient transaction is active`() {
     val fixture = Fixture()
@@ -408,28 +435,24 @@ class BackStackObserverTest {
   }
 
   @Test
-  fun `onBackStackChanged resolves top entry arguments once per update`() {
+  fun `onBackStackChanged preserves scope app fields on the nav transaction`() {
     val fixture = Fixture()
-    val home = HomeRoute()
-    val profile = ProfileRoute("123")
-    val argumentCalls = mutableMapOf<Any, Int>()
-    val sut =
-      fixture.getSut(
-        argumentsExtractor =
-          RouteArgumentsExtractor { entry ->
-            argumentCalls[entry] = (argumentCalls[entry] ?: 0) + 1
-            when (entry) {
-              is HomeRoute -> mapOf("tab" to entry.id)
-              is ProfileRoute -> mapOf("userId" to entry.userId)
-              else -> emptyMap()
-            }
-          }
-      )
+    val scopeApp =
+      App().apply {
+        appName = "Demo App"
+        appIdentifier = "io.sentry.demo"
+      }
+    fixture.scope.contexts.setApp(scopeApp)
+    val sut = fixture.getSut(config = ObserverConfig(enableScreenTracking = true))
 
-    sut.onBackStackChanged(listOf(home, profile))
+    sut.onBackStackChanged(listOf(HomeRoute(), ProfileRoute("123")))
 
-    assertThat(argumentCalls[profile]).isEqualTo(1)
-    assertThat(argumentCalls[home]).isEqualTo(1)
+    val transactionApp = fixture.startedTransactions.single().contexts.app
+    assertThat(transactionApp).isNotNull()
+    assertThat(transactionApp).isNotSameInstanceAs(scopeApp)
+    assertThat(transactionApp?.appName).isEqualTo("Demo App")
+    assertThat(transactionApp?.appIdentifier).isEqualTo("io.sentry.demo")
+    assertThat(transactionApp?.viewNames).isEqualTo(listOf("/ProfileRoute"))
   }
 
   @Test