fix(authenticator): Improve error messaging if auth configuration is invalid/incomplete (#112)

Author: mattcreaser

authenticator/src/main/java/com/amplifyframework/ui/authenticator/AuthenticatorViewModel.kt

@@ -60,11 +60,13 @@ import com.amplifyframework.ui.authenticator.forms.setFieldError
 import com.amplifyframework.ui.authenticator.states.BaseStateImpl
 import com.amplifyframework.ui.authenticator.states.StepStateFactory
 import com.amplifyframework.ui.authenticator.util.AmplifyResult
+import com.amplifyframework.ui.authenticator.util.AuthConfigurationResult
 import com.amplifyframework.ui.authenticator.util.AuthProvider
 import com.amplifyframework.ui.authenticator.util.AuthenticatorMessage
 import com.amplifyframework.ui.authenticator.util.CannotSendCodeMessage
 import com.amplifyframework.ui.authenticator.util.CodeSentMessage
 import com.amplifyframework.ui.authenticator.util.ExpiredCodeMessage
+import com.amplifyframework.ui.authenticator.util.InvalidConfigurationException
 import com.amplifyframework.ui.authenticator.util.InvalidLoginMessage
 import com.amplifyframework.ui.authenticator.util.MissingConfigurationException
 import com.amplifyframework.ui.authenticator.util.NetworkErrorMessage
@@ -121,15 +123,20 @@ internal class AuthenticatorViewModel(
         this.configuration = configuration
 
         viewModelScope.launch {
-            val authConfig = authProvider.getConfiguration()
-
-            if (authConfig == null) {
-                handleGeneralFailure(MissingConfigurationException())
-                return@launch
+            when (val authConfigResult = authProvider.getConfiguration()) {
+                is AuthConfigurationResult.Invalid -> {
+                    handleGeneralFailure(
+                        InvalidConfigurationException(authConfigResult.message, authConfigResult.cause)
+                    )
+                    return@launch
+                }
+                AuthConfigurationResult.Missing -> {
+                    handleGeneralFailure(MissingConfigurationException())
+                    return@launch
+                }
+                is AuthConfigurationResult.Valid -> authConfiguration = authConfigResult.configuration
             }
 
-            authConfiguration = authConfig
-
             stateFactory = StepStateFactory(
                 authConfiguration,
                 buildForm(configuration.signUpForm),

authenticator/src/main/java/com/amplifyframework/ui/authenticator/util/AuthProvider.kt

@@ -101,7 +101,13 @@ internal interface AuthProvider {
 
     fun authStatusEvents(): Flow<HubEvent<*>>
 
-    suspend fun getConfiguration(): AmplifyAuthConfiguration?
+    suspend fun getConfiguration(): AuthConfigurationResult
+}
+
+internal sealed interface AuthConfigurationResult {
+    data class Valid(val configuration: AmplifyAuthConfiguration) : AuthConfigurationResult
+    data class Invalid(val message: String, val cause: Exception? = null) : AuthConfigurationResult
+    object Missing : AuthConfigurationResult
 }
 
 /**
@@ -246,8 +252,8 @@ internal class RealAuthProvider : AuthProvider {
         awaitClose { Amplify.Hub.unsubscribe(token) }
     }
 
-    override suspend fun getConfiguration(): AmplifyAuthConfiguration? {
-        val authConfigJSON = getCognitoPlugin()?.getPluginConfiguration() ?: return null
+    override suspend fun getConfiguration(): AuthConfigurationResult {
+        val authConfigJSON = getCognitoPlugin()?.getPluginConfiguration() ?: return AuthConfigurationResult.Missing
         try {
             val innerJSON = authConfigJSON
                 .getJSONObject("Auth")
@@ -292,14 +298,16 @@ internal class RealAuthProvider : AuthProvider {
                 }
             }.toSet()
 
-            return AmplifyAuthConfiguration(
-                signInMethod,
-                signUpAttributeList,
-                passwordCriteria,
-                verificationMechanisms
+            return AuthConfigurationResult.Valid(
+                AmplifyAuthConfiguration(
+                    signInMethod,
+                    signUpAttributeList,
+                    passwordCriteria,
+                    verificationMechanisms
+                )
             )
         } catch (e: JSONException) {
-            return null
+            return AuthConfigurationResult.Invalid(e.message ?: "Auth configuration is not valid", e)
         }
     }
 

authenticator/src/main/java/com/amplifyframework/ui/authenticator/util/MissingConfigurationException.kt renamed to authenticator/src/main/java/com/amplifyframework/ui/authenticator/util/Exceptions.kt

@@ -26,3 +26,13 @@ class MissingConfigurationException : AuthException(
     "Make sure the Auth plugin is added and Amplify.configure is called. See " +
         "https://docs.amplify.aws/lib/auth/getting-started/q/platform/android/ for details"
 )
+
+/**
+ * Exception that is passed to the errorContent if the configuration passed to the auth plugin is missing a required
+ * property or has an invalid property
+ */
+class InvalidConfigurationException(message: String, cause: Exception?) : AuthException(
+    message = message,
+    recoverySuggestion = "Check that the configuration passed to Amplify.configure has all required fields",
+    cause = cause
+)

authenticator/src/test/java/com/amplifyframework/ui/authenticator/AuthenticatorViewModelTest.kt

@@ -20,6 +20,7 @@ import app.cash.turbine.test
 import com.amplifyframework.auth.result.step.AuthSignInStep
 import com.amplifyframework.ui.authenticator.enums.AuthenticatorStep
 import com.amplifyframework.ui.authenticator.util.AmplifyResult
+import com.amplifyframework.ui.authenticator.util.AuthConfigurationResult
 import com.amplifyframework.ui.authenticator.util.AuthProvider
 import com.amplifyframework.ui.testing.CoroutineTestRule
 import io.kotest.matchers.shouldBe
@@ -29,6 +30,7 @@ import io.mockk.mockk
 import kotlinx.coroutines.ExperimentalCoroutinesApi
 import kotlinx.coroutines.test.advanceUntilIdle
 import kotlinx.coroutines.test.runTest
+import org.junit.Before
 import org.junit.Rule
 import org.junit.Test
 
@@ -46,6 +48,11 @@ class AuthenticatorViewModelTest {
 
     private val viewModel = AuthenticatorViewModel(application, authProvider)
 
+    @Before
+    fun setup() {
+        coEvery { authProvider.getConfiguration() } returns AuthConfigurationResult.Valid(mockk(relaxed = true))
+    }
+
 //region start tests
 
     @Test
@@ -62,7 +69,18 @@ class AuthenticatorViewModelTest {
 
     @Test
     fun `missing configuration results in an error`() = runTest {
-        coEvery { authProvider.getConfiguration() } returns null
+        coEvery { authProvider.getConfiguration() } returns AuthConfigurationResult.Missing
+
+        viewModel.start(mockAuthConfiguration())
+        advanceUntilIdle()
+
+        coVerify(exactly = 0) { authProvider.fetchAuthSession() }
+        viewModel.currentStep shouldBe AuthenticatorStep.Error
+    }
+
+    @Test
+    fun `invalid configuration results in an error`() = runTest {
+        coEvery { authProvider.getConfiguration() } returns AuthConfigurationResult.Invalid("Invalid")
 
         viewModel.start(mockAuthConfiguration())
         advanceUntilIdle()