fix(web): returning to the window keeps a text selection

apps/web/src/components/ChatView.logic.browser.test.ts

@@ -21,11 +21,33 @@ it("keeps keyboard focus on a sidebar row on window return, but not a clicked ro
 
   await userEvent.click(clicked);
   expect(document.activeElement).toBe(clicked);
-  expect(shouldRefocusComposerOnWindowFocus(document.activeElement)).toBe(true);
+  expect(shouldRefocusComposerOnWindowFocus(document.activeElement, document.getSelection())).toBe(
+    true,
+  );
 
   await userEvent.tab();
   expect(document.activeElement).toBe(tabbed);
-  expect(shouldRefocusComposerOnWindowFocus(document.activeElement)).toBe(false);
+  expect(shouldRefocusComposerOnWindowFocus(document.activeElement, document.getSelection())).toBe(
+    false,
+  );
+});
+
+it("leaves a text selection in the timeline alone on window return", async () => {
+  const timeline = document.createElement("div");
+  timeline.tabIndex = -1;
+  const reply = document.createElement("p");
+  reply.textContent = "Steel bridges are also easy to recycle at the end of their life.";
+  timeline.append(reply);
+  document.body.append(timeline);
+  using _timeline = { [Symbol.dispose]: () => timeline.remove() };
+
+  await userEvent.tripleClick(reply);
+  expect(document.activeElement).toBe(timeline);
+  expect(document.getSelection()?.toString()).toContain("Steel bridges");
+  expect(
+    shouldRefocusComposerOnWindowFocus(document.activeElement, document.getSelection()),
+    "refocusing the composer would clear the selected reply text",
+  ).toBe(false);
 });
 
 it("refocuses the composer on window return from a clicked area after a bare key press", async () => {
@@ -48,7 +70,7 @@ it("refocuses the composer on window return from a clicked area after a bare key
   // A window switch can deliver a lone modifier key without moving focus.
   await userEvent.keyboard("{Shift}");
   expect(
-    shouldRefocusComposerOnWindowFocus(document.activeElement),
+    shouldRefocusComposerOnWindowFocus(document.activeElement, document.getSelection()),
     "a clicked area counts as reached from the keyboard after a bare key press",
   ).toBe(true);
 
@@ -57,5 +79,7 @@ it("refocuses the composer on window return from a clicked area after a bare key
   await userEvent.keyboard("{F6}");
   controller.move(1);
   expect(document.activeElement).toBe(conversation);
-  expect(shouldRefocusComposerOnWindowFocus(document.activeElement)).toBe(false);
+  expect(shouldRefocusComposerOnWindowFocus(document.activeElement, document.getSelection())).toBe(
+    false,
+  );
 });

apps/web/src/components/ChatView.logic.ts

@@ -1078,15 +1078,17 @@ export function hasServerAcknowledgedLocalDispatch(input: {
   );
 }
 
-// Returning to the window should land the caret in the composer, so the reader can type right
-// away. The exceptions are places where focus is deliberate: another text field, a terminal in
-// the drawer or the right panel, an open dialog, menu, or popup, or a region or sidebar row
-// reached from the keyboard. A plain focused button or a clicked row yields to the composer.
+// Returning to the window should land the caret in the composer, except where focus or a
+// selection is deliberate: another text field, a terminal, an open dialog, menu, or popup, a
+// region or sidebar row reached from the keyboard, or selected text the composer would clear.
+// A plain focused button or a clicked row yields to the composer.
 export function shouldRefocusComposerOnWindowFocus(
   activeElement:
     | (Pick<Element, "tagName" | "closest" | "getAttribute"> & { isContentEditable?: boolean })
     | null,
+  selection: Pick<Selection, "isCollapsed"> | null,
 ): boolean {
+  if (selection !== null && !selection.isCollapsed) return false;
   if (activeElement === null || activeElement.tagName === "BODY") return true;
   if (
     activeElement.tagName === "INPUT" ||

apps/web/src/components/ChatView.tsx

@@ -2137,7 +2137,7 @@ export default function ChatView(props: ChatViewProps) {
           if (document.querySelector("[data-mcp-app-fullscreen]") !== null) return;
           if (
             !isInSideChatPane(document.activeElement) &&
-            shouldRefocusComposerOnWindowFocus(document.activeElement)
+            shouldRefocusComposerOnWindowFocus(document.activeElement, document.getSelection())
           ) {
             focusComposerStable();
           }