test skipping insertion

spec/unit/room-state.spec.ts

@@ -1122,4 +1122,54 @@ describe("RoomState", function () {
             ).toBeFalsy();
         });
     });
+    describe("skipWrongOrderRoomStateInserts", () => {
+        const idNow = "now";
+        const idBefore = "before";
+        let onRoomStateEvent: (event: MatrixEvent, state: RoomState, lastStateEvent: MatrixEvent | null) => void;
+        const evNow = new MatrixEvent({
+            type: "m.call.member",
+            room_id: roomId,
+            state_key: "@user:example.org",
+            content: {},
+        });
+        evNow.event.unsigned = { replaces_state: idBefore };
+        evNow.event.event_id = idNow;
+
+        const evBefore = new MatrixEvent({
+            type: "m.call.member",
+            room_id: roomId,
+            state_key: "@user:example.org",
+            content: {},
+        });
+
+        const updatedStateWithBefore = jest.fn();
+        const updatedStateWithNow = jest.fn();
+
+        beforeEach(() => {
+            evBefore.event.event_id = idBefore;
+            onRoomStateEvent = (event, _state, _lastState) => {
+                if (event.event.event_id === idNow) {
+                    updatedStateWithNow();
+                } else if (event.event.event_id === idBefore) {
+                    updatedStateWithBefore();
+                }
+            };
+            state.on(RoomStateEvent.Events, onRoomStateEvent);
+        });
+        afterEach(() => {
+            state.off(RoomStateEvent.Events, onRoomStateEvent);
+            updatedStateWithNow.mockReset();
+            updatedStateWithBefore.mockReset();
+        });
+        it("should skip inserting state to the end of the timeline if the current endState events replaces_state id is the same as the inserted events id", () => {
+            state.setStateEvents([evNow, evBefore], { toStartOfTimeline: false });
+            expect(updatedStateWithBefore).not.toHaveBeenCalled();
+            expect(updatedStateWithNow).toHaveBeenCalled();
+        });
+        it("should skip inserting state at the beginning of the timeline if the inserted events replaces_state is the event id of the current startState", () => {
+            state.setStateEvents([evBefore, evNow], { toStartOfTimeline: true });
+            expect(updatedStateWithBefore).toHaveBeenCalled();
+            expect(updatedStateWithNow).not.toHaveBeenCalled();
+        });
+    });
 });