fix(browser): keep tab stable across snapshot and act

src/browser/server-context.ensure-tab-available.prefers-last-target.test.ts

@@ -0,0 +1,100 @@
+import { describe, expect, it, vi } from "vitest";
+
+import type { BrowserServerState } from "./server-context.js";
+import { createBrowserRouteContext } from "./server-context.js";
+
+vi.mock("./chrome.js", () => ({
+  isChromeCdpReady: vi.fn(async () => true),
+  isChromeReachable: vi.fn(async () => true),
+  launchClawdChrome: vi.fn(async () => {
+    throw new Error("unexpected launch");
+  }),
+  resolveClawdUserDataDir: vi.fn(() => "/tmp/clawd"),
+  stopClawdChrome: vi.fn(async () => {}),
+}));
+
+describe("browser server-context ensureTabAvailable", () => {
+  it("sticks to the last selected target when targetId is omitted", async () => {
+    const fetchMock = vi.fn();
+    // 1st call (snapshot): stable ordering A then B (twice)
+    // 2nd call (act): reversed ordering B then A (twice)
+    const responses = [
+      [
+        { id: "A", type: "page", url: "https://a.example", webSocketDebuggerUrl: "ws://x/a" },
+        { id: "B", type: "page", url: "https://b.example", webSocketDebuggerUrl: "ws://x/b" },
+      ],
+      [
+        { id: "A", type: "page", url: "https://a.example", webSocketDebuggerUrl: "ws://x/a" },
+        { id: "B", type: "page", url: "https://b.example", webSocketDebuggerUrl: "ws://x/b" },
+      ],
+      [
+        { id: "B", type: "page", url: "https://b.example", webSocketDebuggerUrl: "ws://x/b" },
+        { id: "A", type: "page", url: "https://a.example", webSocketDebuggerUrl: "ws://x/a" },
+      ],
+      [
+        { id: "B", type: "page", url: "https://b.example", webSocketDebuggerUrl: "ws://x/b" },
+        { id: "A", type: "page", url: "https://a.example", webSocketDebuggerUrl: "ws://x/a" },
+      ],
+    ];
+
+    fetchMock.mockImplementation(async (url: unknown) => {
+      const u = String(url);
+      if (!u.includes("/json/list")) {
+        throw new Error(`unexpected fetch: ${u}`);
+      }
+      const next = responses.shift();
+      if (!next) {
+        throw new Error("no more responses");
+      }
+      return {
+        ok: true,
+        json: async () => next,
+      } as unknown as Response;
+    });
+
+    // @ts-expect-error test override
+    global.fetch = fetchMock;
+
+    const state: BrowserServerState = {
+      // unused in these tests
+      // biome-ignore lint/suspicious/noExplicitAny: test stub
+      server: null as any,
+      port: 0,
+      resolved: {
+        enabled: true,
+        controlUrl: "http://127.0.0.1:18791",
+        controlHost: "127.0.0.1",
+        controlPort: 18791,
+        cdpProtocol: "http",
+        cdpHost: "127.0.0.1",
+        cdpIsLoopback: true,
+        color: "#FF4500",
+        headless: true,
+        noSandbox: false,
+        attachOnly: false,
+        defaultProfile: "chrome",
+        profiles: {
+          chrome: {
+            driver: "extension",
+            cdpUrl: "http://127.0.0.1:18792",
+            cdpPort: 18792,
+            color: "#00AA00",
+          },
+          clawd: { cdpPort: 18800, color: "#FF4500" },
+        },
+      },
+      profiles: new Map(),
+    };
+
+    const ctx = createBrowserRouteContext({
+      getState: () => state,
+    });
+
+    const chrome = ctx.forProfile("chrome");
+    const first = await chrome.ensureTabAvailable();
+    expect(first.targetId).toBe("A");
+    const second = await chrome.ensureTabAvailable();
+    expect(second.targetId).toBe("A");
+  });
+});
+

src/browser/server-context.ts

@@ -86,7 +86,7 @@ function createProfileContext(
     const current = state();
     let profileState = current.profiles.get(profile.name);
     if (!profileState) {
-      profileState = { profile, running: null };
+      profileState = { profile, running: null, lastTargetId: null };
       current.profiles.set(profile.name, profileState);
     }
     return profileState;
@@ -158,6 +158,8 @@ function createProfileContext(
     });
 
     if (!created.id) throw new Error("Failed to open tab (missing id)");
+    const profileState = getProfileState();
+    profileState.lastTargetId = created.id;
     return {
       targetId: created.id,
       title: created.title ?? "",
@@ -276,27 +278,43 @@ function createProfileContext(
 
   const ensureTabAvailable = async (targetId?: string): Promise<BrowserTab> => {
     await ensureBrowserAvailable();
+    const profileState = getProfileState();
     const tabs1 = await listTabs();
     if (tabs1.length === 0) {
+      if (profile.driver === "extension") {
+        throw new Error("tab not found");
+      }
       await openTab("about:blank");
     }
 
     const tabs = await listTabs();
-    const chosen = targetId
-      ? (() => {
-          const resolved = resolveTargetIdFromTabs(targetId, tabs);
-          if (!resolved.ok) {
-            if (resolved.reason === "ambiguous") return "AMBIGUOUS" as const;
-            return null;
-          }
-          return tabs.find((t) => t.targetId === resolved.targetId) ?? null;
-        })()
-      : (tabs.at(0) ?? null);
+    const candidates = tabs.filter((t) => Boolean(t.wsUrl));
+
+    const resolveById = (raw: string) => {
+      const resolved = resolveTargetIdFromTabs(raw, candidates);
+      if (!resolved.ok) {
+        if (resolved.reason === "ambiguous") return "AMBIGUOUS" as const;
+        return null;
+      }
+      return candidates.find((t) => t.targetId === resolved.targetId) ?? null;
+    };
+
+    const pickDefault = () => {
+      const last = profileState.lastTargetId?.trim() || "";
+      const lastResolved = last ? resolveById(last) : null;
+      if (lastResolved && lastResolved !== "AMBIGUOUS") return lastResolved;
+      // Prefer a real page tab first (avoid service workers/background targets).
+      const page = candidates.find((t) => (t.type ?? "page") === "page");
+      return page ?? (candidates.at(0) ?? null);
+    };
+
+    const chosen = targetId ? resolveById(targetId) : pickDefault();
 
     if (chosen === "AMBIGUOUS") {
       throw new Error("ambiguous target id prefix");
     }
     if (!chosen?.wsUrl) throw new Error("tab not found");
+    profileState.lastTargetId = chosen.targetId;
     return chosen;
   };
 
@@ -311,6 +329,8 @@ function createProfileContext(
       throw new Error("tab not found");
     }
     await fetchOk(`${base}/json/activate/${resolved.targetId}`);
+    const profileState = getProfileState();
+    profileState.lastTargetId = resolved.targetId;
   };
 
   const closeTab = async (targetId: string): Promise<void> => {

src/browser/server-context.types.ts

@@ -12,6 +12,8 @@ export type { BrowserTab };
 export type ProfileRuntimeState = {
   profile: ResolvedBrowserProfile;
   running: RunningChrome | null;
+  /** Sticky tab selection when callers omit targetId (keeps snapshot+act consistent). */
+  lastTargetId?: string | null;
 };
 
 export type BrowserServerState = {