Avoid closing the widget in returnToLobby mode

If returnToLobby is enabled then we obviously want to keep the widget open once the user leaves the call.

src/UrlParams.test.ts

@@ -110,8 +110,8 @@ describe("UrlParams", () => {
   });
 
   describe("returnToLobby", () => {
-    it("is true in SPA mode", () => {
-      expect(getUrlParams("?returnToLobby=false").returnToLobby).toBe(true);
+    it("is false in SPA mode", () => {
+      expect(getUrlParams("?returnToLobby=true").returnToLobby).toBe(false);
     });
 
     it("defaults to false in widget mode", () => {

src/UrlParams.ts

@@ -264,7 +264,7 @@ export const getUrlParams = (
       "skipLobby",
       isWidget && intent === UserIntent.StartNewCall,
     ),
-    returnToLobby: isWidget ? parser.getFlagParam("returnToLobby") : true,
+    returnToLobby: isWidget ? parser.getFlagParam("returnToLobby") : false,
     theme: parser.getParam("theme"),
     viaServers: !isWidget ? parser.getParam("viaServers") : null,
     homeserver: !isWidget ? parser.getParam("homeserver") : null,

src/rtcSessionHelpers.test.ts

@@ -6,7 +6,7 @@ Please see LICENSE in the repository root for full details.
 */
 
 import { type MatrixRTCSession } from "matrix-js-sdk/src/matrixrtc/MatrixRTCSession";
-import { expect, test, vi } from "vitest";
+import { expect, onTestFinished, test, vi } from "vitest";
 import { AutoDiscovery } from "matrix-js-sdk/src/autodiscovery";
 import EventEmitter from "events";
 
@@ -15,11 +15,17 @@ import { mockConfig } from "./utils/test";
 import { ElementWidgetActions, widget } from "./widget";
 import { ErrorCode } from "./utils/errors.ts";
 
+const getUrlParams = vi.hoisted(() => vi.fn(() => ({})));
+vi.mock("./UrlParams", () => ({ getUrlParams }));
+
 const actualWidget = await vi.hoisted(async () => vi.importActual("./widget"));
 vi.mock("./widget", () => ({
   ...actualWidget,
   widget: {
-    api: { transport: { send: vi.fn(), reply: vi.fn(), stop: vi.fn() } },
+    api: {
+      setAlwaysOnScreen: (): void => {},
+      transport: { send: vi.fn(), reply: vi.fn(), stop: vi.fn() },
+    },
     lazyActions: new EventEmitter(),
   },
 }));
@@ -109,34 +115,45 @@ test("It joins the correct Session", async () => {
   );
 });
 
-test("leaveRTCSession closes the widget on a normal hangup", async () => {
+async function testLeaveRTCSession(
+  cause: "user" | "error",
+  expectClose: boolean,
+): Promise<void> {
   vi.clearAllMocks();
   const session = { leaveRoomSession: vi.fn() } as unknown as MatrixRTCSession;
-  await leaveRTCSession(session, "user");
+  await leaveRTCSession(session, cause);
   expect(session.leaveRoomSession).toHaveBeenCalled();
   expect(widget!.api.transport.send).toHaveBeenCalledWith(
     ElementWidgetActions.HangupCall,
     expect.anything(),
   );
-  expect(widget!.api.transport.send).toHaveBeenCalledWith(
-    ElementWidgetActions.Close,
-    expect.anything(),
-  );
+  if (expectClose) {
+    expect(widget!.api.transport.send).toHaveBeenCalledWith(
+      ElementWidgetActions.Close,
+      expect.anything(),
+    );
+    expect(widget!.api.transport.stop).toHaveBeenCalled();
+  } else {
+    expect(widget!.api.transport.send).not.toHaveBeenCalledWith(
+      ElementWidgetActions.Close,
+      expect.anything(),
+    );
+    expect(widget!.api.transport.stop).not.toHaveBeenCalled();
+  }
+}
+
+test("leaveRTCSession closes the widget on a normal hangup", async () => {
+  await testLeaveRTCSession("user", true);
 });
 
 test("leaveRTCSession doesn't close the widget on a fatal error", async () => {
-  vi.clearAllMocks();
-  const session = { leaveRoomSession: vi.fn() } as unknown as MatrixRTCSession;
-  await leaveRTCSession(session, "error");
-  expect(session.leaveRoomSession).toHaveBeenCalled();
-  expect(widget!.api.transport.send).toHaveBeenCalledWith(
-    ElementWidgetActions.HangupCall,
-    expect.anything(),
-  );
-  expect(widget!.api.transport.send).not.toHaveBeenCalledWith(
-    ElementWidgetActions.Close,
-    expect.anything(),
-  );
+  await testLeaveRTCSession("error", false);
+});
+
+test("leaveRTCSession doesn't close the widget when returning to lobby", async () => {
+  getUrlParams.mockReturnValue({ returnToLobby: true });
+  onTestFinished(() => void getUrlParams.mockReset());
+  await testLeaveRTCSession("user", false);
 });
 
 test("It fails with configuration error if no live kit url config is set in fallback", async () => {

src/rtcSessionHelpers.ts

@@ -19,6 +19,7 @@ import { PosthogAnalytics } from "./analytics/PosthogAnalytics";
 import { Config } from "./config/Config";
 import { ElementWidgetActions, widget, type WidgetHelpers } from "./widget";
 import { MatrixRTCFocusMissingError } from "./utils/errors.ts";
+import { getUrlParams } from "./UrlParams.ts";
 
 const FOCI_WK_KEY = "org.matrix.msc4143.rtc_foci";
 
@@ -149,7 +150,7 @@ const widgetPostHangupProcedure = async (
   }
   // On a normal user hangup we can shut down and close the widget. But if an
   // error occurs we should keep the widget open until the user reads it.
-  if (cause === "user") {
+  if (cause === "user" && !getUrlParams().returnToLobby) {
     try {
       await widget.api.transport.send(ElementWidgetActions.Close, {});
     } catch (e) {