resolve undefined this in onClick handler (#32576)

* resolve undefined this in onClick handler

* add regression test for bound DisambiguatedProfileViewModel onClick

* Update docs

* add regression for sender profile click mention insertion

* Eslint Fix

playwright/e2e/timeline/timeline.spec.ts

@@ -1008,6 +1008,34 @@ test.describe("Timeline", () => {
             await expect(page.getByRole("button", { name: "Show video" })).toBeVisible();
             await expect(page.locator("video")).not.toBeVisible();
         });
+
+        test("should insert a mention when clicking sender profile in timeline", async ({
+            page,
+            app,
+            homeserver,
+            room,
+        }) => {
+            const senderDisplayName = "SenderBot";
+            const messageFromSender = "message from sender";
+
+            const bot = new Bot(page, homeserver, {
+                displayName: senderDisplayName,
+                autoAcceptInvites: false,
+            });
+            await bot.prepareClient();
+            await app.client.inviteUser(room.roomId, bot.credentials.userId);
+            await bot.joinRoom(room.roomId);
+            await bot.sendMessage(room.roomId, messageFromSender);
+
+            await app.viewRoomById(room.roomId);
+
+            const senderMessageTile = getEventTilesWithBodies(page).filter({ hasText: messageFromSender }).first();
+            await expect(senderMessageTile).toBeVisible();
+
+            await senderMessageTile.locator(".mx_DisambiguatedProfile").click();
+
+            await expect(app.getComposerField().getByText(senderDisplayName)).toBeVisible();
+        });
     });
 
     test.describe("message sending", { tag: ["@no-firefox", "@no-webkit"] }, () => {