Present the last added user first

features/selectusers/impl/src/main/kotlin/io/element/android/features/selectusers/impl/DefaultSelectUsersPresenter.kt

@@ -75,7 +75,7 @@ class DefaultSelectUsersPresenter(private val isMultiSelectionEnabled: Boolean)
         return SelectUsersState(
             searchQuery = searchQuery,
             searchResults = searchResults.value,
-            selectedUsers = selectedUsers.value,
+            selectedUsers = selectedUsers.value.reversed().toImmutableSet(),
             isSearchActive = isSearchActive,
             isMultiSelectionEnabled = isMultiSelectionEnabled,
             eventSink = ::handleEvents,

features/selectusers/impl/src/test/kotlin/io/element/android/features/selectusers/impl/DefaultSelectUsersPresenterTests.kt

@@ -95,15 +95,29 @@ class DefaultSelectSingleUserPresenterTests {
         }.test {
             val initialState = awaitItem()
 
-            val matrixUser = aMatrixUser()
-            initialState.eventSink(SelectUsersEvents.AddToSelection(matrixUser))
-            val selectionAfterAdd = awaitItem().selectedUsers
-            assertThat(selectionAfterAdd).hasSize(1)
-            assertThat(selectionAfterAdd).contains(matrixUser)
+            val userA = aMatrixUser("userA", "A")
+            val userB = aMatrixUser("userB", "B")
+            initialState.eventSink(SelectUsersEvents.AddToSelection(userA))
+            val selectionAfterAddingA = awaitItem().selectedUsers
+            assertThat(selectionAfterAddingA).hasSize(1)
+            assertThat(selectionAfterAddingA).contains(userA)
 
-            initialState.eventSink(SelectUsersEvents.RemoveFromSelection(matrixUser))
-            val selectionAfterRemove = awaitItem().selectedUsers
-            assertThat(selectionAfterRemove).isEmpty()
+            initialState.eventSink(SelectUsersEvents.AddToSelection(userB))
+            val selectionAfterAddingB = awaitItem().selectedUsers
+            assertThat(selectionAfterAddingB).hasSize(2)
+            assertThat(selectionAfterAddingB).contains(userA)
+            assertThat(selectionAfterAddingB).contains(userB)
+            // the last added user should be presented first
+            assertThat(selectionAfterAddingB.first()).isEqualTo(userB)
+
+            initialState.eventSink(SelectUsersEvents.RemoveFromSelection(userB))
+            val selectionAfterRemovingB = awaitItem().selectedUsers
+            assertThat(selectionAfterRemovingB).hasSize(1)
+            assertThat(selectionAfterRemovingB).contains(userA)
+
+            initialState.eventSink(SelectUsersEvents.RemoveFromSelection(userA))
+            val selectionAfterRemovingA = awaitItem().selectedUsers
+            assertThat(selectionAfterRemovingA).isEmpty()
         }
     }
 }

libraries/matrixui/src/main/kotlin/io/element/android/libraries/matrix/ui/components/MatrixUserProvider.kt

@@ -32,9 +32,9 @@ open class MatrixUserProvider : PreviewParameterProvider<MatrixUser> {
         )
 }
 
-fun aMatrixUser() = MatrixUser(
-    id = UserId("@id_of_alice:server.org"),
-    username = "Alice",
+fun aMatrixUser(id: String = "@id_of_alice:server.org", userName: String = "Alice") = MatrixUser(
+    id = UserId(id),
+    username = userName,
     avatarData = anAvatarData()
 )