From 5a1545058bb8e00cd714edaaeea6af401f17988d Mon Sep 17 00:00:00 2001
From: Michael Kaye <1917473+michaelkaye@users.noreply.github.com>
Date: Wed, 18 May 2022 11:20:21 +0100
Subject: [PATCH] Instead of using a magic number, explicitly test for the
 events we expect.

This permits a clear error when the events are missing / extra and while
not making the test invulnerable to future changes in events, should be
explicit on what's changed.
---
 .../timeline/TimelineForwardPaginationTest.kt | 25 +++++++++++++++----
 1 file changed, 20 insertions(+), 5 deletions(-)

diff --git a/matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/session/room/timeline/TimelineForwardPaginationTest.kt b/matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/session/room/timeline/TimelineForwardPaginationTest.kt
index d5b4a07fc0..e407c1b42d 100644
--- a/matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/session/room/timeline/TimelineForwardPaginationTest.kt
+++ b/matrix-sdk-android/src/androidTest/java/org/matrix/android/sdk/session/room/timeline/TimelineForwardPaginationTest.kt
@@ -140,9 +140,24 @@ class TimelineForwardPaginationTest : InstrumentedTest {
             aliceTimeline.hasMoreToLoad(Timeline.Direction.BACKWARDS).shouldBeFalse()
 
             assertEquals(EventType.STATE_ROOM_CREATE, snapshot.lastOrNull()?.root?.getClearType())
-            // 6 for room creation item (backward pagination), 1 for the context, and 50 for the forward pagination
-            // 6 + 1 + 50
-            assertEquals(57, snapshot.size)
+
+            // We explicitly test all the types we expect here, as we expect 51 messages and "some" state events
+            // But state events can change over time. So this acts as a kinda documentation of what we expect and
+            // provides a good error message if it doesn't match
+
+            val snapshotTypes = mutableMapOf<String?, Int>()
+            snapshot.groupingBy { it -> it.root.type }.eachCountTo(snapshotTypes)
+            // Some state events on room creation
+            assertEquals("m.room.name", 1, snapshotTypes.remove("m.room.name"))
+            assertEquals("m.room.guest_access", 1, snapshotTypes.remove("m.room.guest_access"))
+            assertEquals("m.room.history_visibility", 1, snapshotTypes.remove("m.room.history_visibility"))
+            assertEquals("m.room.join_rules", 1, snapshotTypes.remove("m.room.join_rules"))
+            assertEquals("m.room.power_levels", 1, snapshotTypes.remove("m.room.power_levels"))
+            assertEquals("m.room.create", 1, snapshotTypes.remove("m.room.create"))
+            assertEquals("m.room.member", 1, snapshotTypes.remove("m.room.member"))
+            // 50 from pagination + 1 context
+            assertEquals("m.room.message", 51, snapshotTypes.remove("m.room.message"))
+            assertEquals("Additional events found in timeline", setOf<String>(), snapshotTypes.keys)
         }
 
         // Alice paginates once again FORWARD for 50 events
@@ -152,8 +167,8 @@ class TimelineForwardPaginationTest : InstrumentedTest {
             val snapshot = runBlocking {
                 aliceTimeline.awaitPaginate(Timeline.Direction.FORWARDS, 50)
             }
-            // 6 for room creation item (backward pagination),and numberOfMessagesToSend (all the message of the room)
-            snapshot.size == 6 + numberOfMessagesToSend &&
+            // 7 for room creation item (backward pagination),and numberOfMessagesToSend (all the message of the room)
+            snapshot.size == 7 + numberOfMessagesToSend &&
                     snapshot.checkSendOrder(message, numberOfMessagesToSend, 0)
 
             // The timeline is fully loaded