Ensure user cannot select unsupported homeserver. In this case show the appropriate error (parity with iOS)

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerPresenter.kt

@@ -13,6 +13,7 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import dev.zacsweers.metro.Inject
+import io.element.android.features.login.impl.R
 import io.element.android.features.login.impl.accesscontrol.DefaultAccountProviderAccessControl
 import io.element.android.features.login.impl.accountprovider.AccountProvider
 import io.element.android.features.login.impl.accountprovider.AccountProviderDataSource
@@ -60,7 +61,13 @@ class ChangeServerPresenter(
                 title = data.title,
                 accountProviderUrl = data.url,
             )
-            authenticationService.setHomeserver(data.url).getOrThrow()
+            val details = authenticationService.setHomeserver(data.url).getOrThrow()
+            if (details.supportsOidcLogin.not() && details.supportsPasswordLogin.not()) {
+                // Unsupported homeserver
+                throw ChangeServerError.Error(
+                    messageId = R.string.screen_login_error_unsupported_authentication,
+                )
+            }
             // Homeserver is valid, remember user choice
             accountProviderDataSource.userSelection(data)
         }.runCatchingUpdatingState(changeServerAction, errorTransform = ChangeServerError::from)

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerStateProvider.kt

@@ -8,6 +8,7 @@
 package io.element.android.features.login.impl.changeserver
 
 import androidx.compose.ui.tooling.preview.PreviewParameterProvider
+import io.element.android.features.login.impl.R
 import io.element.android.features.login.impl.error.ChangeServerError
 import io.element.android.libraries.architecture.AsyncData
 import io.element.android.libraries.ui.strings.CommonStrings
@@ -34,6 +35,13 @@ open class ChangeServerStateProvider : PreviewParameterProvider<ChangeServerStat
                     ),
                 )
             ),
+            aChangeServerState(
+                changeServerAction = AsyncData.Failure(
+                    ChangeServerError.Error(
+                        R.string.screen_login_error_unsupported_authentication
+                    )
+                )
+            ),
         )
 }
 

features/login/impl/src/main/kotlin/io/element/android/features/login/impl/error/ChangeServerError.kt

@@ -40,6 +40,7 @@ sealed class ChangeServerError : Exception() {
 
     companion object {
         fun from(error: Throwable): ChangeServerError = when (error) {
+            is ChangeServerError -> error
             is AuthenticationException.SlidingSyncVersion -> SlidingSyncAlert
             is AuthenticationException.Oidc -> Error(messageStr = error.message)
             is AccountProviderAccessException.NeedElementProException -> NeedElementPro(

features/login/impl/src/test/kotlin/io/element/android/features/login/impl/changeserver/ChangeServerPresenterTest.kt

@@ -10,6 +10,7 @@ package io.element.android.features.login.impl.changeserver
 import com.google.common.truth.Truth.assertThat
 import io.element.android.features.enterprise.api.EnterpriseService
 import io.element.android.features.enterprise.test.FakeEnterpriseService
+import io.element.android.features.login.impl.R
 import io.element.android.features.login.impl.aMatrixHomeServerDetails
 import io.element.android.features.login.impl.accesscontrol.DefaultAccountProviderAccessControl
 import io.element.android.features.login.impl.accountprovider.AccountProvider
@@ -49,7 +50,7 @@ class ChangeServerPresenterTest {
     fun `present - change server ok`() = runTest {
         val authenticationService = FakeMatrixAuthenticationService(
             setHomeserverResult = {
-                Result.success(aMatrixHomeServerDetails())
+                Result.success(aMatrixHomeServerDetails(supportsOidcLogin = true))
             },
         )
         createPresenter(
@@ -95,6 +96,32 @@ class ChangeServerPresenterTest {
         }
     }
 
+    @Test
+    fun `present - change server unsupported server`() = runTest {
+        val authenticationService = FakeMatrixAuthenticationService(
+            setHomeserverResult = {
+                Result.success(aMatrixHomeServerDetails())
+            },
+        )
+        createPresenter(
+            enterpriseService = FakeEnterpriseService(
+                isAllowedToConnectToHomeserverResult = { true },
+            ),
+            authenticationService = authenticationService,
+        ).test {
+            val initialState = awaitItem()
+            assertThat(initialState.changeServerAction).isEqualTo(AsyncData.Uninitialized)
+            initialState.eventSink.invoke(ChangeServerEvents.ChangeServer(AccountProvider(url = A_HOMESERVER_URL)))
+            val loadingState = awaitItem()
+            assertThat(loadingState.changeServerAction).isInstanceOf(AsyncData.Loading::class.java)
+            val failureState = awaitItem()
+            assertThat(failureState.changeServerAction).isInstanceOf(AsyncData.Failure::class.java)
+            assertThat(failureState.changeServerAction.errorOrNull()).isEqualTo(
+                ChangeServerError.Error(R.string.screen_login_error_unsupported_authentication)
+            )
+        }
+    }
+
     @Test
     fun `present - change server not allowed error`() = runTest {
         val isAllowedToConnectToHomeserverResult = lambdaRecorder<String, Boolean> { false }