Simplify UpdateResult.Failure to object

The errorMessage parameter was never shown to users, so
changed Failure from a data class to an object for simplicity.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: nbradbury

WordPress/src/main/java/org/wordpress/android/ui/reader/subscription/ReaderBlogSubscriptionUseCase.kt

@@ -75,7 +75,7 @@ class ReaderBlogSubscriptionUseCase @Inject constructor(
     @Subscribe(threadMode = ThreadMode.MAIN)
     fun onSubscriptionUpdated(event: OnSubscriptionUpdated) {
         val result = if (event.isError) {
-            UpdateResult.Failure(event.error?.message)
+            UpdateResult.Failure
         } else {
             UpdateResult.Success
         }
@@ -90,6 +90,6 @@ class ReaderBlogSubscriptionUseCase @Inject constructor(
     sealed class UpdateResult {
         object Success : UpdateResult()
         object NoNetwork : UpdateResult()
-        data class Failure(val errorMessage: String?) : UpdateResult()
+        object Failure : UpdateResult()
     }
 }

WordPress/src/test/java/org/wordpress/android/ui/reader/subscription/ReaderBlogSubscriptionUseCaseTest.kt

@@ -115,8 +115,7 @@ class ReaderBlogSubscriptionUseCaseTest : BaseUnitTest() {
 
         val result = useCase.updateNotifyPosts(BLOG_ID, true)
 
-        assertThat(result).isInstanceOf(UpdateResult.Failure::class.java)
-        assertThat((result as UpdateResult.Failure).errorMessage).isEqualTo(ERROR_MESSAGE)
+        assertThat(result).isEqualTo(UpdateResult.Failure)
     }
 
     @Test

WordPress/src/test/java/org/wordpress/android/ui/reader/subscription/ReaderSubscriptionSettingsViewModelTest.kt

@@ -116,7 +116,7 @@ class ReaderSubscriptionSettingsViewModelTest : BaseUnitTest() {
     fun `onNotifyPostsToggled reverts state on failure`() = test {
         initializeViewModel(notifyPostsEnabled = false)
         whenever(subscriptionUseCase.updateNotifyPosts(BLOG_ID, true))
-            .thenReturn(UpdateResult.Failure("Error"))
+            .thenReturn(UpdateResult.Failure)
 
         viewModel.onNotifyPostsToggled(true)
 
@@ -128,7 +128,7 @@ class ReaderSubscriptionSettingsViewModelTest : BaseUnitTest() {
     fun `onNotifyPostsToggled shows error snackbar on failure`() = test {
         initializeViewModel()
         whenever(subscriptionUseCase.updateNotifyPosts(BLOG_ID, true))
-            .thenReturn(UpdateResult.Failure("Error"))
+            .thenReturn(UpdateResult.Failure)
 
         viewModel.onNotifyPostsToggled(true)
 
@@ -188,7 +188,7 @@ class ReaderSubscriptionSettingsViewModelTest : BaseUnitTest() {
     fun `onEmailPostsToggled reverts state on failure`() = test {
         initializeViewModel(emailPostsEnabled = false)
         whenever(subscriptionUseCase.updateEmailPosts(BLOG_ID, true))
-            .thenReturn(UpdateResult.Failure("Error"))
+            .thenReturn(UpdateResult.Failure)
 
         viewModel.onEmailPostsToggled(true)
 
@@ -200,7 +200,7 @@ class ReaderSubscriptionSettingsViewModelTest : BaseUnitTest() {
     fun `onEmailPostsToggled shows error snackbar on failure`() = test {
         initializeViewModel()
         whenever(subscriptionUseCase.updateEmailPosts(BLOG_ID, true))
-            .thenReturn(UpdateResult.Failure("Error"))
+            .thenReturn(UpdateResult.Failure)
 
         viewModel.onEmailPostsToggled(true)
 
@@ -260,7 +260,7 @@ class ReaderSubscriptionSettingsViewModelTest : BaseUnitTest() {
     fun `onEmailCommentsToggled reverts state on failure`() = test {
         initializeViewModel(emailCommentsEnabled = false)
         whenever(subscriptionUseCase.updateEmailComments(BLOG_ID, true))
-            .thenReturn(UpdateResult.Failure("Error"))
+            .thenReturn(UpdateResult.Failure)
 
         viewModel.onEmailCommentsToggled(true)
 
@@ -272,7 +272,7 @@ class ReaderSubscriptionSettingsViewModelTest : BaseUnitTest() {
     fun `onEmailCommentsToggled shows error snackbar on failure`() = test {
         initializeViewModel()
         whenever(subscriptionUseCase.updateEmailComments(BLOG_ID, true))
-            .thenReturn(UpdateResult.Failure("Error"))
+            .thenReturn(UpdateResult.Failure)
 
         viewModel.onEmailCommentsToggled(true)