fix(desktop): new tabs the agent opens from links no longer steal composer focus

apps/desktop/src/preview/DesktopBrowserHost.test.ts

@@ -947,7 +947,7 @@ describe("DesktopBrowserHost", () => {
     }).pipe(Effect.scoped),
   );
 
-  it.effect("tells a download the person clicked from one the agent's input started", () =>
+  it.effect("tells a person's action from one the agent's input started", () =>
     Effect.gen(function* () {
       const host = yield* DesktopBrowserHost.make;
       const debuggee = makeDebuggee();
@@ -960,7 +960,7 @@ describe("DesktopBrowserHost", () => {
           message: encodeJson({ id: 1, method: "DOM.getDocument", params: {} }),
         }),
       );
-      expect(host.humanStartedDownload(debuggee.tab.webContents)).toBe(true);
+      expect(host.agentActedRecently(debuggee.tab.webContents)).toBe(false);
       yield* host.handleCommandLine(
         encodeJson({
           type: "cdp",
@@ -972,7 +972,7 @@ describe("DesktopBrowserHost", () => {
           }),
         }),
       );
-      expect(host.humanStartedDownload(debuggee.tab.webContents)).toBe(false);
+      expect(host.agentActedRecently(debuggee.tab.webContents)).toBe(true);
     }),
   );
 

apps/desktop/src/preview/DesktopBrowserHost.ts

@@ -24,7 +24,7 @@ const AGENT_INPUT_COMMAND =
   /"method":"(?:Input\.|Page\.navigate"|Runtime\.(?:evaluate|callFunctionOn)")/;
 /** The same commands as above, by method, for the relay's sends. */
 const AGENT_INPUT_METHOD = /^(?:Input\.|Page\.navigate$|Runtime\.(?:evaluate|callFunctionOn)$)/;
-const AGENT_DOWNLOAD_WINDOW_MS = 5_000;
+const AGENT_INPUT_WINDOW_MS = 5_000;
 const FOCUS_IDLE = "5 seconds";
 
 export interface DesktopBrowserTabKey {
@@ -87,7 +87,7 @@ export class DesktopBrowserHost extends Context.Service<
     readonly handleCommandLine: (line: string) => Effect.Effect<void>;
     readonly attach: (key: DesktopBrowserTabKey, debuggee: DesktopBrowserTabDebugger) => void;
     readonly detach: (key: DesktopBrowserTabKey) => void;
-    readonly humanStartedDownload: (source: Electron.WebContents) => boolean;
+    readonly agentActedRecently: (source: Electron.WebContents) => boolean;
     readonly placeDownload: (source: Electron.WebContents, item: Electron.DownloadItem) => boolean;
     readonly pointers: Stream.Stream<{
       readonly key: DesktopBrowserTabKey;
@@ -482,9 +482,9 @@ export const make = Effect.gen(function* () {
       relayFor(tab).receive(command.value.message);
     });
 
-  const humanStartedDownload = (source: Electron.WebContents) => {
+  const agentActedRecently = (source: Electron.WebContents) => {
     const tab = [...tabs.values()].find((candidate) => candidate.debuggee.webContents === source);
-    return tab !== undefined && performance.now() - tab.agentInputAt > AGENT_DOWNLOAD_WINDOW_MS;
+    return tab !== undefined && performance.now() - tab.agentInputAt <= AGENT_INPUT_WINDOW_MS;
   };
 
   const announceAll = Effect.suspend(() => {
@@ -515,7 +515,7 @@ export const make = Effect.gen(function* () {
     attach,
     detach,
     placeDownload,
-    humanStartedDownload,
+    agentActedRecently,
   });
 });
 

apps/desktop/src/preview/Manager.test.ts

@@ -1812,6 +1812,72 @@ describe("PreviewManager", () => {
       }).pipe(Effect.provide(managerLayer()), Effect.scoped),
   );
 
+  effectIt.effect("opens a new-tab link the agent clicked in the background", () =>
+    Effect.gen(function* () {
+      const host = yield* DesktopBrowserHost.DesktopBrowserHost;
+      const serverTab = { threadId: "thread-1", tabId: "server-tab-1" };
+      const contents = Object.assign(
+        makeTestPreviewWebContents(async () => {
+          throw new Error("unused");
+        }, 42),
+        { isDevToolsOpened: () => false, getUserAgent: () => "Electron", focusedFrame: {} },
+      );
+      fromId.mockReturnValue(contents);
+      const manager = yield* PreviewManager.PreviewManager;
+      const openLinks = yield* Queue.unbounded<{ url: string; background: boolean }>();
+      yield* manager.subscribeOpenLinks(({ url, background }) =>
+        Queue.offer(openLinks, { url, background }).pipe(Effect.asVoid),
+      );
+      const attached = yield* Deferred.make<void>();
+      yield* host.events.pipe(
+        Stream.runForEach((line) =>
+          new TextDecoder().decode(line).includes('"type":"attached"')
+            ? Deferred.succeed(attached, undefined)
+            : Effect.void,
+        ),
+        Effect.forkScoped,
+      );
+      yield* manager.createTab("tab_1", { serverTab });
+      yield* manager.registerWebview("tab_1", 42);
+      yield* Deferred.await(attached);
+      const openWindow = vi.mocked(contents.setWindowOpenHandler).mock.calls[0]![0];
+      const clickBlankLink = (url: string) =>
+        openWindow({ url, disposition: "foreground-tab" } as Electron.HandlerDetails);
+
+      clickBlankLink("https://example.com/person");
+      expect(yield* Queue.take(openLinks)).toEqual({
+        url: "https://example.com/person",
+        background: false,
+      });
+
+      Object.assign(contents, { focusedFrame: null });
+      yield* host.handleCommandLine(
+        JSON.stringify({
+          type: "cdp",
+          ...serverTab,
+          message: JSON.stringify({
+            id: 1,
+            method: "Input.dispatchMouseEvent",
+            params: { type: "mousePressed", x: 10, y: 10, button: "left", clickCount: 1 },
+            sessionId: "t3-preview-page",
+          }),
+        }),
+      );
+      clickBlankLink("https://example.com/agent");
+      expect(yield* Queue.take(openLinks)).toEqual({
+        url: "https://example.com/agent",
+        background: true,
+      });
+
+      Object.assign(contents, { focusedFrame: {} });
+      clickBlankLink("https://example.com/person-after-agent");
+      expect(yield* Queue.take(openLinks)).toEqual({
+        url: "https://example.com/person-after-agent",
+        background: false,
+      });
+    }).pipe(Effect.provide(managerLayer()), Effect.scoped),
+  );
+
   effectIt.effect("discards a screenshot that resolves after its guest is replaced", () =>
     withManager((manager) =>
       Effect.gen(function* () {

apps/desktop/src/preview/Manager.ts

@@ -1548,7 +1548,10 @@ const makeNativeOperations = Effect.fn("PreviewManager.makeOperations")(function
               emitOpenLink({
                 tabId,
                 url: details.url,
-                background: details.disposition === "background-tab",
+                // A person's click focuses a guest frame; GuestInput hands focus back after the agent's press.
+                background:
+                  details.disposition === "background-tab" ||
+                  (browserHost.agentActedRecently(wc) && wc.focusedFrame === null),
               }),
             );
             return { action: "deny" };
@@ -3598,8 +3601,8 @@ export const make = Effect.gen(function* PreviewManagerMake() {
     downloadSessions.add(session);
     session.on("will-download", (_event, item, source) => {
       // Decided before the server's path is set: placing it consumes the guid.
-      const human = browserHost.humanStartedDownload(source);
-      if (!browserHost.placeDownload(source, item) || !human) return;
+      const agentStarted = browserHost.agentActedRecently(source);
+      if (!browserHost.placeDownload(source, item) || agentStarted) return;
       item.once("done", (_doneEvent, state) => {
         if (state !== "completed") return;
         runForkDownload(