timeline(tests): ASCII art ✨

Author: bnjbvr

crates/matrix-sdk-ui/src/timeline/tests/virt.rs

@@ -97,41 +97,56 @@ async fn test_update_read_marker() {
     let f = &timeline.factory;
     timeline.handle_live_event(f.text_msg("A").sender(&own_user)).await;
 
+    // Timeline: [A].
+    // No read marker.
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     let event_id1 = item.as_event().unwrap().event_id().unwrap().to_owned();
 
+    // Timeline: [day-divider, A].
     let day_divider = assert_next_matches!(stream, VectorDiff::PushFront { value } => value);
     assert!(day_divider.is_day_divider());
 
-    timeline.controller.handle_fully_read_marker(event_id1.to_owned()).await;
+    timeline.controller.handle_fully_read_marker(event_id1.clone()).await;
 
     // Nothing should happen, the marker cannot be added at the end.
+    // Timeline: [A].
+    //            ^-- fully read
+    assert!(stream.next().now_or_never().is_none());
 
+    // Timeline: [day-divider, A, B].
     timeline.handle_live_event(f.text_msg("B").sender(&BOB)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     let event_id2 = item.as_event().unwrap().event_id().unwrap().to_owned();
 
     // Now the read marker appears after the first event.
+    // Timeline: [day-divider, A, read-marker, B].
+    //            fully read --^
     let item = assert_next_matches!(stream, VectorDiff::Insert { index: 2, value } => value);
     assert_matches!(item.as_virtual(), Some(VirtualTimelineItem::ReadMarker));
 
     timeline.controller.handle_fully_read_marker(event_id2.clone()).await;
 
     // The read marker is removed but not reinserted, because it cannot be added at
     // the end.
+    // Timeline: [day-divider, A, B].
+    //                            ^-- fully read
     assert_next_matches!(stream, VectorDiff::Remove { index: 2 });
 
+    // Timeline: [day-divider, A, B, C].
+    //                            ^-- fully read
     timeline.handle_live_event(f.text_msg("C").sender(&BOB)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     let event_id3 = item.as_event().unwrap().event_id().unwrap().to_owned();
 
     // Now the read marker is reinserted after the second event.
+    // Timeline: [day-divider, A, B, read-marker, C].
+    //                            ^-- fully read
     let marker = assert_next_matches!(stream, VectorDiff::Insert { index: 3, value } => value);
     assert!(marker.is_read_marker());
 
     // Nothing should happen if the fully read event is set back to an older event
     // sent by another user.
-    timeline.controller.handle_fully_read_marker(event_id1.to_owned()).await;
+    timeline.controller.handle_fully_read_marker(event_id1).await;
     assert!(stream.next().now_or_never().is_none());
 
     // Nothing should happen if the fully read event isn't found.
@@ -143,18 +158,27 @@ async fn test_update_read_marker() {
     timeline.controller.handle_fully_read_marker(event_id2).await;
     assert!(stream.next().now_or_never().is_none());
 
+    // Timeline: [day-divider, A, B, read-marker, C, D].
+    //                            ^-- fully read
     timeline.handle_live_event(f.text_msg("D").sender(&BOB)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     let event_id4 = item.as_event().unwrap().event_id().unwrap().to_owned();
 
     timeline.controller.handle_fully_read_marker(event_id3).await;
 
     // The read marker is moved after the third event (sent by another user).
+    // Timeline: [day-divider, A, B, C, D].
+    //                  fully read --^
     assert_next_matches!(stream, VectorDiff::Remove { index: 3 });
+
+    // Timeline: [day-divider, A, B, C, read-marker, D].
+    //                  fully read --^
     let marker = assert_next_matches!(stream, VectorDiff::Insert { index: 4, value } => value);
     assert!(marker.is_read_marker());
 
     // If the current user sends an event afterwards, the read marker doesn't move.
+    // Timeline: [day-divider, A, B, C, read-marker, D, E].
+    //                  fully read --^
     timeline.handle_live_event(f.text_msg("E").sender(&own_user)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     item.as_event().unwrap();
@@ -163,28 +187,43 @@ async fn test_update_read_marker() {
 
     // If the marker moved forward to another user's event, and there's no other
     // event sent from another user, then it will be removed.
+    // Timeline: [day-divider, A, B, C, D, E].
+    //                     fully read --^
     timeline.controller.handle_fully_read_marker(event_id4).await;
     assert_next_matches!(stream, VectorDiff::Remove { index: 4 });
 
     assert!(stream.next().now_or_never().is_none());
 
     // When a last event is inserted by ourselves, still no read marker.
+    // Timeline: [day-divider, A, B, C, D, E, F].
+    //                     fully read --^
     timeline.handle_live_event(f.text_msg("F").sender(&own_user)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     item.as_event().unwrap();
 
+    // Timeline: [day-divider, A, B, C, D, E, F, G].
+    //                     fully read --^
     timeline.handle_live_event(f.text_msg("G").sender(&own_user)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     item.as_event().unwrap();
 
     assert!(stream.next().now_or_never().is_none());
 
-    // But when it's another user who sent the event, then we get a read marker for
-    // their message.
+    // But when it's another user who sent the event, then we get a read marker just
+    // before their message. It is the first message that's both after the
+    // fully-read event and not sent by us.
+    //
+    // Timeline: [day-divider, A, B, C, D, E, F, G, H].
+    //                     fully read --^
     timeline.handle_live_event(f.text_msg("H").sender(&BOB)).await;
     let item = assert_next_matches!(stream, VectorDiff::PushBack { value } => value);
     item.as_event().unwrap();
 
+    //                                     [our own]              v-- sent by Bob
+    // Timeline: [day-divider, A, B, C, D,  E, F, G, read-marker, H].
+    //                     fully read --^
     let marker = assert_next_matches!(stream, VectorDiff::Insert { index: 8, value } => value);
     assert!(marker.is_read_marker());
+
+    assert!(stream.next().now_or_never().is_none());
 }