diff --git a/test/components/structures/CallEventGrouper-test.ts b/test/components/structures/CallEventGrouper-test.ts
new file mode 100644
index 0000000000..98a5a16a22
--- /dev/null
+++ b/test/components/structures/CallEventGrouper-test.ts
@@ -0,0 +1,124 @@
+import "../../skinned-sdk";
+import { stubClient } from '../../test-utils';
+import { MatrixClientPeg } from '../../../src/MatrixClientPeg';
+import { MatrixClient } from 'matrix-js-sdk';
+import { EventType } from "matrix-js-sdk/src/@types/event";
+import CallEventGrouper, { CustomCallState } from "../../../src/components/structures/CallEventGrouper";
+import { CallState } from "matrix-js-sdk/src/webrtc/call";
+
+const MY_USER_ID = "@me:here";
+const THEIR_USER_ID = "@they:here";
+
+let client: MatrixClient;
+
+describe('CallEventGrouper', () => {
+    beforeEach(() => {
+        stubClient();
+        client = MatrixClientPeg.get();
+        client.getUserId = () => {
+            return MY_USER_ID;
+        };
+    });
+
+    it("detects a missed call", () => {
+        const grouper = new CallEventGrouper();
+
+        grouper.add({
+            getContent: () => {
+                return {
+                    call_id: "callId",
+                };
+            },
+            getType: () => {
+                return EventType.CallInvite;
+            },
+            sender: {
+                userId: THEIR_USER_ID,
+            },
+        });
+
+        expect(grouper.state).toBe(CustomCallState.Missed);
+    });
+
+    it("detects an ended call", () => {
+        const grouperHangup = new CallEventGrouper();
+        const grouperReject = new CallEventGrouper();
+
+        grouperHangup.add({
+            getContent: () => {
+                return {
+                    call_id: "callId",
+                };
+            },
+            getType: () => {
+                return EventType.CallInvite;
+            },
+            sender: {
+                userId: MY_USER_ID,
+            },
+        });
+        grouperHangup.add({
+            getContent: () => {
+                return {
+                    call_id: "callId",
+                };
+            },
+            getType: () => {
+                return EventType.CallHangup;
+            },
+            sender: {
+                userId: THEIR_USER_ID,
+            },
+        });
+
+        grouperReject.add({
+            getContent: () => {
+                return {
+                    call_id: "callId",
+                };
+            },
+            getType: () => {
+                return EventType.CallInvite;
+            },
+            sender: {
+                userId: MY_USER_ID,
+            },
+        });
+        grouperReject.add({
+            getContent: () => {
+                return {
+                    call_id: "callId",
+                };
+            },
+            getType: () => {
+                return EventType.CallReject;
+            },
+            sender: {
+                userId: THEIR_USER_ID,
+            },
+        });
+
+        expect(grouperHangup.state).toBe(CallState.Ended);
+        expect(grouperReject.state).toBe(CallState.Ended);
+    });
+
+    it("detects call type", () => {
+        const grouper = new CallEventGrouper();
+
+        grouper.add({
+            getContent: () => {
+                return {
+                    call_id: "callId",
+                    offer: {
+                        sdp: "this is definitely an SDP m=video",
+                    },
+                };
+            },
+            getType: () => {
+                return EventType.CallInvite;
+            },
+        });
+
+        expect(grouper.isVoice).toBe(false);
+    });
+});