Improvement: failure message shows that appID is missing

OneSignalSDK/onesignal/core/src/main/java/com/onesignal/internal/OneSignalImp.kt

@@ -52,6 +52,9 @@ internal class OneSignalImp(
     @Volatile
     private var initState: InitState = InitState.NOT_STARTED
 
+    // Save the exception pointing to the caller that triggered init, not the async worker thread.
+    private var initFailureException: Exception? = null
+
     override val sdkVersion: String = OneSignalUtils.sdkVersion
 
     override val isInitialized: Boolean
@@ -279,7 +282,11 @@ internal class OneSignalImp(
         val startupService = bootstrapServices()
         val result = resolveAppId(appId, configModel, preferencesService)
         if (result.failed) {
-            Logging.warn("suspendInitInternal: no appId provided or found in legacy config.")
+            val message = "No OneSignal appId provided or found in local storage. Please pass a valid appId to initWithContext()."
+            val exception = IllegalStateException(message)
+            // attach the real crash cause to the init failure exception that will be throw shortly after
+            initFailureException?.addSuppressed(exception)
+            Logging.warn(message)
             initState = InitState.FAILED
             notifyInitComplete()
             return false
@@ -395,12 +402,12 @@ internal class OneSignalImp(
 
                 // Re-check state after waiting - init might have failed during the wait
                 if (initState == InitState.FAILED) {
-                    throw IllegalStateException("Initialization failed. Cannot proceed.")
+                    throw initFailureException ?: IllegalStateException("Initialization failed. Cannot proceed.")
                 }
                 // initState is guaranteed to be SUCCESS here - consistent state
             }
             InitState.FAILED -> {
-                throw IllegalStateException("Initialization failed. Cannot proceed.")
+                throw initFailureException ?: IllegalStateException("Initialization failed. Cannot proceed.")
             }
             else -> {
                 // SUCCESS - already initialized, no need to wait
@@ -506,6 +513,9 @@ internal class OneSignalImp(
     ): Boolean {
         Logging.log(LogLevel.DEBUG, "initWithContext(context: $context, appId: $appId)")
 
+        // This ensures the stack trace points to the caller that triggered init, not the async worker thread.
+        initFailureException = IllegalStateException("OneSignal initWithContext failed.")
+
         // Use IO dispatcher for initialization to prevent ANRs and optimize for I/O operations
         return withContext(ioDispatcher) {
             // do not do this again if already initialized or init is in progress

OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/application/SDKInitTests.kt

@@ -37,20 +37,6 @@ class SDKInitTests : FunSpec({
 
     beforeAny {
         Logging.logLevel = LogLevel.NONE
-
-        // Aggressive pre-test cleanup to avoid state leakage across tests
-        val context = getApplicationContext<Context>()
-        val prefs = context.getSharedPreferences("OneSignal", Context.MODE_PRIVATE)
-        prefs.edit()
-            .clear()
-            .commit()
-
-        val otherPrefs = context.getSharedPreferences("com.onesignal", Context.MODE_PRIVATE)
-        otherPrefs.edit()
-            .clear()
-            .commit()
-
-        Thread.sleep(100)
     }
 
     afterAny {
@@ -65,19 +51,27 @@ class SDKInitTests : FunSpec({
         otherPrefs.edit()
             .clear()
             .commit()
+    }
 
-        // Wait longer to ensure cleanup is complete
-        Thread.sleep(100)
+    test("accessor instances after initWithContext without appID shows the failure reason") {
+        // Given
+        val context = getApplicationContext<Context>()
+        val os = OneSignalImp()
 
-        // Clear any in-memory state by initializing and logging out a fresh instance
-        try {
-            val os = OneSignalImp()
-            os.initWithContext(context, "appId")
-            os.logout()
-            Thread.sleep(100)
-        } catch (ignored: Exception) {
-            // ignore cleanup exceptions
+        // When
+        os.initWithContext(context)
+
+        // Then
+        val ex = shouldThrow<IllegalStateException> {
+            os.user.onesignalId // Should trigger waitUntilInitInternal → throw failure message
         }
+        ex.message shouldBe "suspendInitInternal: no appId provided or found in local storage. Please pass a valid appId to initWithContext()."
+
+        // Calling initWithContext with an appID after the failure should not throw anymore
+        val result = os.initWithContext(context, "appID")
+        waitForInitialization(os)
+        result shouldBe true
+        os.isInitialized shouldBe true
     }
 
     test("OneSignal accessors throw before calling initWithContext") {