Add "reason" to leaveRoom.

src/MatrixClient.ts

@@ -1162,11 +1162,12 @@ export class MatrixClient extends EventEmitter {
     /**
      * Leaves the given room
      * @param {string} roomId the room ID to leave
+     * @param {string=} reason Optional reason to be included as the reason for leaving the room.
      * @returns {Promise<any>} resolves when left
      */
     @timedMatrixClientFunctionCall()
-    public leaveRoom(roomId: string): Promise<any> {
-        return this.doRequest("POST", "/_matrix/client/v3/rooms/" + encodeURIComponent(roomId) + "/leave", null, {});
+    public leaveRoom(roomId: string, reason?: string): Promise<any> {
+        return this.doRequest("POST", "/_matrix/client/v3/rooms/" + encodeURIComponent(roomId) + "/leave", null, { reason });
     }
 
     /**

src/appservice/Intent.ts

@@ -201,12 +201,13 @@ export class Intent {
     /**
      * Leaves the given room.
      * @param {string} roomId The room ID to leave
+     * @param {string=} reason Optional reason to be included as the reason for leaving the room.
      * @returns {Promise<any>} Resolves when the room has been left.
      */
     @timedIntentFunctionCall()
-    public async leaveRoom(roomId: string): Promise<any> {
+    public async leaveRoom(roomId: string, reason?: string): Promise<any> {
         await this.ensureRegistered();
-        return this.client.leaveRoom(roomId).then(async () => {
+        return this.client.leaveRoom(roomId, reason).then(async () => {
             // Recalculate joined rooms now that we've left a room
             await this.refreshJoinedRooms();
         });

test/MatrixClientTest.ts

@@ -3340,6 +3340,21 @@ describe('MatrixClient', () => {
 
             await Promise.all([client.leaveRoom(roomId), http.flushAllExpected()]);
         });
+        it('should include a reason if provided', async () => {
+            const { client, http, hsUrl } = createTestClient();
+
+            const roomId = "!testing:example.org";
+            const reason = "I am done testing here";
+
+            // noinspection TypeScriptValidateJSTypes
+            http.when("POST", "/_matrix/client/v3/rooms").respond(200, (path, content) => {
+                expect(content).toEqual({ reason });
+                expect(path).toEqual(`${hsUrl}/_matrix/client/v3/rooms/${encodeURIComponent(roomId)}/leave`);
+                return {};
+            });
+
+            await Promise.all([client.leaveRoom(roomId, reason), http.flushAllExpected()]);
+        });
     });
 
     describe('forgetRoom', () => {