Resolve display names in mentions in real time (#3051)

* Resolve display names in mentions in real time

* Use `LocalRoomMemberProfilesCache` to avoid having to implement `TextMessagePresenter`

* Also use local composition provider for `MentionSpanProvider`

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/MessagesFlowNode.kt

@@ -18,7 +18,9 @@ package io.element.android.features.messages.impl
 
 import android.os.Parcelable
 import androidx.compose.runtime.Composable
+import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.ui.Modifier
+import androidx.lifecycle.lifecycleScope
 import com.bumble.appyx.core.modality.BuildContext
 import com.bumble.appyx.core.node.Node
 import com.bumble.appyx.core.node.node
@@ -64,12 +66,20 @@ import io.element.android.libraries.matrix.api.core.RoomId
 import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.media.MediaSource
 import io.element.android.libraries.matrix.api.permalink.PermalinkData
+import io.element.android.libraries.matrix.api.room.MatrixRoom
+import io.element.android.libraries.matrix.api.room.joinedRoomMembers
 import io.element.android.libraries.matrix.api.timeline.item.TimelineItemDebugInfo
+import io.element.android.libraries.matrix.ui.messages.LocalRoomMemberProfilesCache
+import io.element.android.libraries.matrix.ui.messages.RoomMemberProfilesCache
 import io.element.android.libraries.mediaviewer.api.local.MediaInfo
 import io.element.android.libraries.mediaviewer.api.viewer.MediaViewerNode
+import io.element.android.libraries.textcomposer.mentions.LocalMentionSpanProvider
+import io.element.android.libraries.textcomposer.mentions.MentionSpanProvider
 import io.element.android.services.analytics.api.AnalyticsService
 import io.element.android.services.analyticsproviders.api.trackers.captureInteraction
 import kotlinx.collections.immutable.ImmutableList
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
 import kotlinx.parcelize.Parcelize
 
 @ContributesNode(RoomScope::class)
@@ -82,6 +92,9 @@ class MessagesFlowNode @AssistedInject constructor(
     private val createPollEntryPoint: CreatePollEntryPoint,
     private val elementCallEntryPoint: ElementCallEntryPoint,
     private val analyticsService: AnalyticsService,
+    private val room: MatrixRoom,
+    private val roomMemberProfilesCache: RoomMemberProfilesCache,
+    mentionSpanProviderFactory: MentionSpanProvider.Factory,
 ) : BaseFlowNode<MessagesFlowNode.NavTarget>(
     backstack = BackStack(
         initialElement = NavTarget.Messages,
@@ -137,6 +150,18 @@ class MessagesFlowNode @AssistedInject constructor(
 
     private val callback = plugins<MessagesEntryPoint.Callback>().firstOrNull()
 
+    private val mentionSpanProvider = mentionSpanProviderFactory.create(room.sessionId.value)
+
+    override fun onBuilt() {
+        super.onBuilt()
+
+        room.membersStateFlow
+            .onEach { membersState ->
+                roomMemberProfilesCache.replace(membersState.joinedRoomMembers())
+            }
+            .launchIn(lifecycleScope)
+    }
+
     override fun resolve(navTarget: NavTarget, buildContext: BuildContext): Node {
         return when (navTarget) {
             is NavTarget.Messages -> {
@@ -345,6 +370,13 @@ class MessagesFlowNode @AssistedInject constructor(
 
     @Composable
     override fun View(modifier: Modifier) {
-        BackstackWithOverlayBox(modifier)
+        mentionSpanProvider.updateStyles()
+
+        CompositionLocalProvider(
+            LocalRoomMemberProfilesCache provides roomMemberProfilesCache,
+            LocalMentionSpanProvider provides mentionSpanProvider,
+        ) {
+            BackstackWithOverlayBox(modifier)
+        }
     }
 }

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerPresenter.kt

@@ -54,15 +54,14 @@ import io.element.android.libraries.matrix.api.permalink.PermalinkBuilder
 import io.element.android.libraries.matrix.api.permalink.PermalinkParser
 import io.element.android.libraries.matrix.api.room.MatrixRoom
 import io.element.android.libraries.matrix.api.room.Mention
-import io.element.android.libraries.matrix.api.user.CurrentSessionIdHolder
 import io.element.android.libraries.mediapickers.api.PickerProvider
 import io.element.android.libraries.mediaupload.api.MediaSender
 import io.element.android.libraries.mediaviewer.api.local.LocalMediaFactory
 import io.element.android.libraries.permissions.api.PermissionsEvents
 import io.element.android.libraries.permissions.api.PermissionsPresenter
 import io.element.android.libraries.preferences.api.store.SessionPreferencesStore
+import io.element.android.libraries.textcomposer.mentions.LocalMentionSpanProvider
 import io.element.android.libraries.textcomposer.mentions.ResolvedMentionSuggestion
-import io.element.android.libraries.textcomposer.mentions.rememberMentionSpanProvider
 import io.element.android.libraries.textcomposer.model.Message
 import io.element.android.libraries.textcomposer.model.MessageComposerMode
 import io.element.android.libraries.textcomposer.model.Suggestion
@@ -104,7 +103,6 @@ class MessageComposerPresenter @Inject constructor(
     private val analyticsService: AnalyticsService,
     private val messageComposerContext: DefaultMessageComposerContext,
     private val richTextEditorStateFactory: RichTextEditorStateFactory,
-    private val currentSessionIdHolder: CurrentSessionIdHolder,
     private val permalinkParser: PermalinkParser,
     private val permalinkBuilder: PermalinkBuilder,
     permissionsPresenterFactory: PermissionsPresenter.Factory,
@@ -215,7 +213,7 @@ class MessageComposerPresenter @Inject constructor(
         val memberSuggestions = remember { mutableStateListOf<ResolvedMentionSuggestion>() }
         LaunchedEffect(isMentionsEnabled) {
             if (!isMentionsEnabled) return@LaunchedEffect
-            val currentUserId = currentSessionIdHolder.current
+            val currentUserId = room.sessionId
 
             suspend fun canSendRoomMention(): Boolean {
                 val userCanSendAtRoom = room.canUserTriggerRoomNotification(currentUserId).getOrDefault(false)
@@ -279,14 +277,7 @@ class MessageComposerPresenter @Inject constructor(
             }
         }
 
-        val mentionSpanProvider = if (isTesting) {
-            null
-        } else {
-            rememberMentionSpanProvider(
-                currentUserId = room.sessionId,
-                permalinkParser = permalinkParser,
-            )
-        }
+        val mentionSpanProvider = LocalMentionSpanProvider.current
 
         fun handleEvents(event: MessageComposerEvents) {
             when (event) {
@@ -415,19 +406,17 @@ class MessageComposerPresenter @Inject constructor(
                                     richTextEditorState.insertAtRoomMentionAtSuggestion()
                                 }
                                 is ResolvedMentionSuggestion.Member -> {
-                                    val text = mention.roomMember.displayName?.prependIndent("@") ?: mention.roomMember.userId.value
+                                    val text = mention.roomMember.userId.value
                                     val link = permalinkBuilder.permalinkForUser(mention.roomMember.userId).getOrNull() ?: return@launch
                                     richTextEditorState.insertMentionAtSuggestion(text = text, link = link)
                                 }
                             }
                         } else if (markdownTextEditorState.currentMentionSuggestion != null) {
-                            mentionSpanProvider?.let {
-                                markdownTextEditorState.insertMention(
-                                    mention = event.mention,
-                                    mentionSpanProvider = it,
-                                    permalinkBuilder = permalinkBuilder,
-                                )
-                            }
+                            markdownTextEditorState.insertMention(
+                                mention = event.mention,
+                                mentionSpanProvider = mentionSpanProvider,
+                                permalinkBuilder = permalinkBuilder,
+                            )
                             suggestionSearchTrigger.value = null
                         }
                     }
@@ -446,7 +435,6 @@ class MessageComposerPresenter @Inject constructor(
             canCreatePoll = canCreatePoll.value,
             attachmentsState = attachmentsState.value,
             memberSuggestions = memberSuggestions.toPersistentList(),
-            currentUserId = currentSessionIdHolder.current,
             eventSink = { handleEvents(it) }
         )
     }

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerState.kt

@@ -19,7 +19,6 @@ package io.element.android.features.messages.impl.messagecomposer
 import androidx.compose.runtime.Immutable
 import androidx.compose.runtime.Stable
 import io.element.android.features.messages.impl.attachments.Attachment
-import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.permalink.PermalinkParser
 import io.element.android.libraries.textcomposer.mentions.ResolvedMentionSuggestion
 import io.element.android.libraries.textcomposer.model.MessageComposerMode
@@ -38,7 +37,6 @@ data class MessageComposerState(
     val canCreatePoll: Boolean,
     val attachmentsState: AttachmentsState,
     val memberSuggestions: ImmutableList<ResolvedMentionSuggestion>,
-    val currentUserId: UserId,
     val eventSink: (MessageComposerEvents) -> Unit,
 )
 

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerStateProvider.kt

@@ -17,7 +17,6 @@
 package io.element.android.features.messages.impl.messagecomposer
 
 import androidx.compose.ui.tooling.preview.PreviewParameterProvider
-import io.element.android.libraries.matrix.api.core.UserId
 import io.element.android.libraries.matrix.api.permalink.PermalinkData
 import io.element.android.libraries.matrix.api.permalink.PermalinkParser
 import io.element.android.libraries.textcomposer.aRichTextEditorState
@@ -57,6 +56,5 @@ fun aMessageComposerState(
     canCreatePoll = canCreatePoll,
     attachmentsState = attachmentsState,
     memberSuggestions = memberSuggestions,
-    currentUserId = UserId("@alice:localhost"),
     eventSink = {},
 )

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/messagecomposer/MessageComposerView.kt

@@ -124,7 +124,6 @@ internal fun MessageComposerView(
         onReceiveSuggestion = ::onSuggestionReceived,
         onError = ::onError,
         onTyping = ::onTyping,
-        currentUserId = state.currentUserId,
         onSelectRichContent = ::sendUri,
     )
 }

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/DefaultHtmlConverterProvider.kt

@@ -28,9 +28,8 @@ import io.element.android.libraries.core.bool.orFalse
 import io.element.android.libraries.di.SessionScope
 import io.element.android.libraries.di.SingleIn
 import io.element.android.libraries.matrix.api.core.UserId
-import io.element.android.libraries.matrix.api.permalink.PermalinkParser
 import io.element.android.libraries.textcomposer.ElementRichTextEditorStyle
-import io.element.android.libraries.textcomposer.mentions.rememberMentionSpanProvider
+import io.element.android.libraries.textcomposer.mentions.LocalMentionSpanProvider
 import io.element.android.wysiwyg.compose.StyledHtmlConverter
 import io.element.android.wysiwyg.display.MentionDisplayHandler
 import io.element.android.wysiwyg.display.TextDisplay
@@ -40,9 +39,7 @@ import javax.inject.Inject
 
 @ContributesBinding(SessionScope::class)
 @SingleIn(SessionScope::class)
-class DefaultHtmlConverterProvider @Inject constructor(
-    private val permalinkParser: PermalinkParser,
-) : HtmlConverterProvider {
+class DefaultHtmlConverterProvider @Inject constructor() : HtmlConverterProvider {
     private val htmlConverter: MutableState<HtmlConverter?> = mutableStateOf(null)
 
     @Composable
@@ -53,10 +50,7 @@ class DefaultHtmlConverterProvider @Inject constructor(
         }
 
         val editorStyle = ElementRichTextEditorStyle.textStyle()
-        val mentionSpanProvider = rememberMentionSpanProvider(
-            currentUserId = currentUserId,
-            permalinkParser = permalinkParser,
-        )
+        val mentionSpanProvider = LocalMentionSpanProvider.current
 
         val context = LocalContext.current
 

features/messages/impl/src/main/kotlin/io/element/android/features/messages/impl/timeline/components/event/TimelineItemTextView.kt

@@ -17,11 +17,15 @@
 package io.element.android.features.messages.impl.timeline.components.event
 
 import android.text.SpannableString
+import androidx.annotation.VisibleForTesting
 import androidx.compose.foundation.layout.Box
 import androidx.compose.material3.LocalContentColor
 import androidx.compose.material3.LocalTextStyle
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.runtime.collectAsState
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.remember
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.semantics.contentDescription
 import androidx.compose.ui.semantics.semantics
@@ -33,7 +37,12 @@ import io.element.android.features.messages.impl.timeline.model.event.TimelineIt
 import io.element.android.features.messages.impl.timeline.model.event.TimelineItemTextBasedContentProvider
 import io.element.android.libraries.designsystem.preview.ElementPreview
 import io.element.android.libraries.designsystem.preview.PreviewsDayNight
+import io.element.android.libraries.matrix.api.core.UserId
+import io.element.android.libraries.matrix.ui.messages.LocalRoomMemberProfilesCache
+import io.element.android.libraries.matrix.ui.messages.RoomMemberProfilesCache
 import io.element.android.libraries.textcomposer.ElementRichTextEditorStyle
+import io.element.android.libraries.textcomposer.mentions.MentionSpan
+import io.element.android.libraries.textcomposer.mentions.getMentionSpans
 import io.element.android.wysiwyg.compose.EditorStyledText
 
 @Composable
@@ -47,10 +56,8 @@ fun TimelineItemTextView(
         LocalContentColor provides ElementTheme.colors.textPrimary,
         LocalTextStyle provides ElementTheme.typography.fontBodyLgRegular
     ) {
-        val formattedBody = content.formattedBody
-        val body = SpannableString(formattedBody ?: content.body)
-
-        Box(modifier.semantics { contentDescription = body.toString() }) {
+        val body = getTextWithResolvedMentions(content)
+        Box(modifier.semantics { contentDescription = content.plainText }) {
             EditorStyledText(
                 text = body,
                 onLinkClickedListener = onLinkClick,
@@ -62,6 +69,39 @@ fun TimelineItemTextView(
     }
 }
 
+@VisibleForTesting(otherwise = VisibleForTesting.PRIVATE)
+@Composable
+internal fun getTextWithResolvedMentions(content: TimelineItemTextBasedContent): CharSequence {
+    val userProfileCache = LocalRoomMemberProfilesCache.current
+    val lastCacheUpdate by userProfileCache.lastCacheUpdate.collectAsState()
+    val formattedBody = remember(content.htmlBody, lastCacheUpdate) {
+        updateMentionSpans(content.formattedBody, userProfileCache)
+        SpannableString(content.formattedBody ?: content.body)
+    }
+
+    return formattedBody
+}
+
+private fun updateMentionSpans(text: CharSequence?, cache: RoomMemberProfilesCache): Boolean {
+    var changedContents = false
+    if (text != null) {
+        for (mentionSpan in text.getMentionSpans()) {
+            when (mentionSpan.type) {
+                MentionSpan.Type.USER -> {
+                    val displayName = cache.getDisplayName(UserId(mentionSpan.rawValue)) ?: mentionSpan.rawValue
+                    if (mentionSpan.text != displayName) {
+                        changedContents = true
+                        mentionSpan.text = displayName
+                    }
+                }
+                // Nothing yet for room mentions
+                else -> Unit
+            }
+        }
+    }
+    return changedContents
+}
+
 @PreviewsDayNight
 @Composable
 internal fun TimelineItemTextViewPreview(

features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/MessagesPresenterTest.kt

@@ -69,13 +69,11 @@ import io.element.android.libraries.matrix.api.room.MatrixRoom
 import io.element.android.libraries.matrix.api.room.MatrixRoomMembersState
 import io.element.android.libraries.matrix.api.room.MessageEventType
 import io.element.android.libraries.matrix.api.room.RoomMembershipState
-import io.element.android.libraries.matrix.api.user.CurrentSessionIdHolder
 import io.element.android.libraries.matrix.test.AN_AVATAR_URL
 import io.element.android.libraries.matrix.test.AN_EVENT_ID
 import io.element.android.libraries.matrix.test.A_ROOM_ID
 import io.element.android.libraries.matrix.test.A_SESSION_ID
 import io.element.android.libraries.matrix.test.A_SESSION_ID_2
-import io.element.android.libraries.matrix.test.FakeMatrixClient
 import io.element.android.libraries.matrix.test.core.aBuildMeta
 import io.element.android.libraries.matrix.test.permalink.FakePermalinkBuilder
 import io.element.android.libraries.matrix.test.permalink.FakePermalinkParser
@@ -778,7 +776,6 @@ class MessagesPresenterTest {
             messageComposerContext = DefaultMessageComposerContext(),
             richTextEditorStateFactory = TestRichTextEditorStateFactory(),
             permissionsPresenterFactory = permissionsPresenterFactory,
-            currentSessionIdHolder = CurrentSessionIdHolder(FakeMatrixClient(A_SESSION_ID)),
             permalinkParser = FakePermalinkParser(),
             permalinkBuilder = FakePermalinkBuilder(),
             timelineController = TimelineController(matrixRoom),

features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/MessagesViewTest.kt

@@ -470,7 +470,9 @@ private fun <R : TestRule> AndroidComposeTestRule<R, ComponentActivity>.setMessa
 ) {
     setContent {
         // Cannot use the RichTextEditor, so simulate a LocalInspectionMode
-        CompositionLocalProvider(LocalInspectionMode provides true) {
+        CompositionLocalProvider(
+            LocalInspectionMode provides true
+        ) {
             MessagesView(
                 state = state,
                 onBackClick = onBackClick,

features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/textcomposer/MessageComposerPresenterTest.kt

@@ -47,19 +47,16 @@ import io.element.android.libraries.matrix.api.room.MatrixRoom
 import io.element.android.libraries.matrix.api.room.MatrixRoomMembersState
 import io.element.android.libraries.matrix.api.room.Mention
 import io.element.android.libraries.matrix.api.room.RoomMembershipState
-import io.element.android.libraries.matrix.api.user.CurrentSessionIdHolder
 import io.element.android.libraries.matrix.test.ANOTHER_MESSAGE
 import io.element.android.libraries.matrix.test.AN_EVENT_ID
 import io.element.android.libraries.matrix.test.A_MESSAGE
 import io.element.android.libraries.matrix.test.A_REPLY
-import io.element.android.libraries.matrix.test.A_SESSION_ID
 import io.element.android.libraries.matrix.test.A_TRANSACTION_ID
 import io.element.android.libraries.matrix.test.A_USER_ID
 import io.element.android.libraries.matrix.test.A_USER_ID_2
 import io.element.android.libraries.matrix.test.A_USER_ID_3
 import io.element.android.libraries.matrix.test.A_USER_ID_4
 import io.element.android.libraries.matrix.test.A_USER_NAME
-import io.element.android.libraries.matrix.test.FakeMatrixClient
 import io.element.android.libraries.matrix.test.permalink.FakePermalinkBuilder
 import io.element.android.libraries.matrix.test.permalink.FakePermalinkParser
 import io.element.android.libraries.matrix.test.room.FakeMatrixRoom
@@ -1057,7 +1054,6 @@ class MessageComposerPresenterTest {
         analyticsService,
         DefaultMessageComposerContext(),
         TestRichTextEditorStateFactory(),
-        currentSessionIdHolder = CurrentSessionIdHolder(FakeMatrixClient(A_SESSION_ID)),
         permissionsPresenterFactory = FakePermissionsPresenterFactory(permissionPresenter),
         permalinkParser = FakePermalinkParser(),
         permalinkBuilder = permalinkBuilder,

features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/timeline/DefaultHtmlConverterProviderTest.kt

@@ -21,7 +21,6 @@ import androidx.compose.ui.platform.LocalInspectionMode
 import androidx.compose.ui.test.junit4.createComposeRule
 import com.google.common.truth.Truth.assertThat
 import io.element.android.libraries.matrix.test.A_USER_ID
-import io.element.android.libraries.matrix.test.permalink.FakePermalinkParser
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -33,9 +32,7 @@ class DefaultHtmlConverterProviderTest {
 
     @Test
     fun `calling provide without calling Update first should throw an exception`() {
-        val provider = DefaultHtmlConverterProvider(
-            permalinkParser = FakePermalinkParser(),
-        )
+        val provider = DefaultHtmlConverterProvider()
 
         val exception = runCatching { provider.provide() }.exceptionOrNull()
 
@@ -44,9 +41,7 @@ class DefaultHtmlConverterProviderTest {
 
     @Test
     fun `calling provide after calling Update first should return an HtmlConverter`() {
-        val provider = DefaultHtmlConverterProvider(
-            permalinkParser = FakePermalinkParser(),
-        )
+        val provider = DefaultHtmlConverterProvider()
         composeTestRule.setContent {
             CompositionLocalProvider(LocalInspectionMode provides true) {
                 provider.Update(currentUserId = A_USER_ID)

features/messages/impl/src/test/kotlin/io/element/android/features/messages/impl/timeline/components/event/TimelineTextViewTest.kt

@@ -0,0 +1,175 @@
+/*
+ * Copyright (c) 2024 New Vector Ltd
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.element.android.features.messages.impl.timeline.components.event
+
+import android.text.SpannableString
+import androidx.activity.ComponentActivity
+import androidx.compose.runtime.CompositionLocalProvider
+import androidx.compose.ui.test.junit4.AndroidComposeTestRule
+import androidx.compose.ui.test.junit4.createAndroidComposeRule
+import androidx.core.text.buildSpannedString
+import androidx.core.text.inSpans
+import androidx.test.ext.junit.runners.AndroidJUnit4
+import com.google.common.truth.Truth.assertThat
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemTextBasedContent
+import io.element.android.features.messages.impl.timeline.model.event.TimelineItemTextContent
+import io.element.android.libraries.matrix.test.A_ROOM_ID
+import io.element.android.libraries.matrix.test.A_ROOM_ID_2
+import io.element.android.libraries.matrix.test.A_USER_ID
+import io.element.android.libraries.matrix.test.A_USER_ID_2
+import io.element.android.libraries.matrix.test.A_USER_NAME
+import io.element.android.libraries.matrix.test.room.aRoomMember
+import io.element.android.libraries.matrix.ui.messages.LocalRoomMemberProfilesCache
+import io.element.android.libraries.matrix.ui.messages.RoomMemberProfilesCache
+import io.element.android.libraries.textcomposer.mentions.MentionSpan
+import io.element.android.libraries.textcomposer.mentions.getMentionSpans
+import io.element.android.wysiwyg.view.spans.CustomMentionSpan
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.test.runTest
+import org.junit.Rule
+import org.junit.Test
+import org.junit.rules.TestRule
+import org.junit.runner.RunWith
+
+@RunWith(AndroidJUnit4::class)
+class TimelineTextViewTest {
+    @get:Rule val rule = createAndroidComposeRule<ComponentActivity>()
+
+    @Test
+    fun `getTextWithResolvedMentions - does nothing for a non spannable CharSequence`() = runTest {
+        val charSequence = "Hello <a href=\"https://matrix.to/#/@alice:example.com\">@alice:example.com</a>"
+
+        val result = rule.getText(aTextContentWithFormattedBody(charSequence))
+
+        assertThat(result.getMentionSpans()).isEmpty()
+    }
+
+    @Test
+    fun `getTextWithResolvedMentions - does nothing if there are no mentions`() = runTest {
+        val charSequence = SpannableString("Hello <a href=\"https://matrix.to/#/@alice:example.com\">@alice:example.com</a>")
+
+        val result = rule.getText(aTextContentWithFormattedBody(charSequence))
+
+        assertThat(result.getMentionSpans()).isEmpty()
+    }
+
+    @Test
+    fun `getTextWithResolvedMentions - just returns the body if there is no formattedBody`() = runTest {
+        val charSequence = "Hello <a href=\"https://matrix.to/#/@alice:example.com\">@alice:example.com</a>"
+
+        val result = rule.getText(aTextContentWithFormattedBody(body = charSequence, formattedBody = null))
+
+        assertThat(result.getMentionSpans()).isEmpty()
+        assertThat(result.toString()).isEqualTo(charSequence)
+    }
+
+    @Test
+    fun `getTextWithResolvedMentions - with Room mention does nothing`() = runTest {
+        val charSequence = buildSpannedString {
+            append("Hello ")
+            inSpans(aMentionSpan(rawValue = A_ROOM_ID_2.value, type = MentionSpan.Type.ROOM)) {
+                append(A_ROOM_ID.value)
+            }
+        }
+
+        val result = rule.getText(aTextContentWithFormattedBody(charSequence))
+
+        assertThat(result.getMentionSpans().firstOrNull()?.text).isEmpty()
+        assertThat(result).isEqualTo(charSequence)
+    }
+
+    @Test
+    fun `getTextWithResolvedMentions - replaces MentionSpan's text`() = runTest {
+        val charSequence = buildSpannedString {
+            append("Hello ")
+            inSpans(aMentionSpan(rawValue = A_USER_ID.value)) {
+                append("@NotAlice")
+            }
+        }
+
+        val result = rule.getText(aTextContentWithFormattedBody(charSequence))
+
+        assertThat(result.getMentionSpans().firstOrNull()?.text).isEqualTo("alice")
+    }
+
+    @Test
+    fun `getTextWithResolvedMentions - replaces MentionSpan's text inside CustomMentionSpan`() = runTest {
+        val charSequence = buildSpannedString {
+            append("Hello ")
+            inSpans(CustomMentionSpan(aMentionSpan(rawValue = A_USER_ID.value))) {
+                append("@NotAlice")
+            }
+        }
+
+        val result = rule.getText(aTextContentWithFormattedBody(charSequence))
+
+        assertThat(result.getMentionSpans().firstOrNull()?.text).isEqualTo("alice")
+    }
+
+    @Test
+    fun `getTextWithResolvedMentions - replaces MentionSpan's text with user id if no display name is cached`() = runTest {
+        val charSequence = buildSpannedString {
+            append("Hello ")
+            inSpans(aMentionSpan(rawValue = A_USER_ID_2.value)) {
+                append("@NotAlice")
+            }
+        }
+
+        val result = rule.getText(aTextContentWithFormattedBody(charSequence))
+
+        assertThat(result.getMentionSpans().firstOrNull()?.text).isEqualTo(A_USER_ID_2.value)
+    }
+
+    private suspend fun <R : TestRule> AndroidComposeTestRule<R, ComponentActivity>.getText(
+        content: TimelineItemTextBasedContent,
+    ): CharSequence {
+        val completable = CompletableDeferred<CharSequence>()
+        setContent {
+            val roomMemberProfilesCache = RoomMemberProfilesCache().apply {
+                replace(listOf(aRoomMember(userId = A_USER_ID, displayName = A_USER_NAME)))
+            }
+            CompositionLocalProvider(
+                LocalRoomMemberProfilesCache provides roomMemberProfilesCache,
+            ) {
+                completable.complete(getTextWithResolvedMentions(content = content))
+            }
+        }
+        return completable.await()
+    }
+
+    private fun aMentionSpan(
+        rawValue: String,
+        text: String = "",
+        type: MentionSpan.Type = MentionSpan.Type.USER
+    ) = MentionSpan(
+        text = text,
+        rawValue = rawValue,
+        type = type,
+        backgroundColor = 0,
+        textColor = 0,
+        startPadding = 0,
+        endPadding = 0,
+    )
+
+    private fun aTextContentWithFormattedBody(formattedBody: CharSequence?, body: String = "") =
+        TimelineItemTextContent(
+            body = body,
+            htmlDocument = null,
+            formattedBody = formattedBody,
+            isEdited = false
+        )
+}