[Room member list] Display room member list (#276)

* Implement room member list

* Move timeline initialization back to `TimelinePresenter`.

* Fix crash when the `innerRoom` inside a `RustMatrixRoom` is destroyed but `syncUpdateFlow` is still running.

* Address review comments

appnav/src/main/kotlin/io/element/android/appnav/RoomFlowNode.kt

@@ -69,6 +69,8 @@ class RoomFlowNode @AssistedInject constructor(
 
     private val inputs: Inputs = inputs()
 
+    private val roomFlowPresenter = RoomFlowPresenter(inputs.room)
+
     init {
         lifecycle.subscribe(
             onCreate = {
@@ -110,6 +112,7 @@ class RoomFlowNode @AssistedInject constructor(
 
     @Composable
     override fun View(modifier: Modifier) {
+        roomFlowPresenter.present()
         Children(
             navModel = backstack,
             modifier = modifier,

appnav/src/main/kotlin/io/element/android/appnav/RoomFlowPresenter.kt

@@ -0,0 +1,46 @@
+/*
+ * Copyright (c) 2023 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.appnav
+
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import io.element.android.libraries.architecture.Presenter
+import io.element.android.libraries.matrix.api.room.MatrixRoom
+import timber.log.Timber
+
+class RoomFlowPresenter(
+    private val room: MatrixRoom,
+) : Presenter<RoomFlowState> {
+
+    @Composable
+    override fun present(): RoomFlowState {
+        // Preload room members so we can quickly detect if the room is a DM room
+        LaunchedEffect(Unit) {
+            room.fetchMembers()
+                .onFailure {
+                    Timber.e(it, "Fail to fetch members for room ${room.roomId}")
+                }.onSuccess {
+                    Timber.v("Success fetching members for room ${room.roomId}")
+                }
+        }
+
+        return RoomFlowState
+    }
+}
+
+// At first the return type was Unit, but detekt complained about it
+object RoomFlowState

appnav/src/test/kotlin/io/element/android/appnav/RoomFlowPresenterTest.kt

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2023 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.appnav
+
+import app.cash.molecule.RecompositionClock
+import app.cash.molecule.moleculeFlow
+import app.cash.turbine.test
+import com.google.common.truth.Truth
+import io.element.android.libraries.matrix.test.room.FakeMatrixRoom
+import io.element.android.libraries.matrix.test.timeline.FakeMatrixTimeline
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import java.lang.IllegalStateException
+
+class RoomFlowPresenterTest {
+
+    @Test
+    fun `present - fetches room members`() = runTest {
+        val fakeTimeline = FakeMatrixTimeline()
+        val room = FakeMatrixRoom(matrixTimeline = fakeTimeline)
+        val presenter = RoomFlowPresenter(room)
+
+        Truth.assertThat(room.areMembersFetched).isFalse()
+        moleculeFlow(RecompositionClock.Immediate) {
+            presenter.present()
+        }.test {
+            Truth.assertThat(room.areMembersFetched).isTrue()
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+
+    @Test
+    fun `present - recovers from error while fetching room members`() = runTest {
+        val fakeTimeline = FakeMatrixTimeline()
+        val room = FakeMatrixRoom(matrixTimeline = fakeTimeline).apply {
+            givenFetchMemberResult(Result.failure(IllegalStateException("Some error")))
+        }
+        val presenter = RoomFlowPresenter(room)
+
+        Truth.assertThat(room.areMembersFetched).isFalse()
+        moleculeFlow(RecompositionClock.Immediate) {
+            presenter.present()
+        }.test {
+            Truth.assertThat(room.areMembersFetched).isFalse()
+            cancelAndIgnoreRemainingEvents()
+        }
+    }
+}