fix(panel): 切换服务器或用户时不再先显示上一个对象的数据，详情页随路由参数重新挂载，列表翻页与筛选保留旧行直到新结果到达

panel/src/lib/hooks.test.tsx

@@ -0,0 +1,102 @@
+// @vitest-environment jsdom
+import { describe, it, expect } from "vitest";
+import { act, renderHook } from "@testing-library/react";
+import { useAsync, type AsyncOptions } from "./hooks";
+
+// A request the test settles by hand, one per call, in call order.
+function requests() {
+  const pending: { id: string; resolve: (v: string) => void; reject: (e: unknown) => void }[] = [];
+  const fetch = (id: string) =>
+    new Promise<string>((resolve, reject) => pending.push({ id, resolve, reject }));
+  const settle = async (i: number, how: { ok: string } | { fail: unknown }) => {
+    await act(async () => {
+      if ("ok" in how) pending[i].resolve(how.ok);
+      else pending[i].reject(how.fail);
+    });
+  };
+  return { pending, fetch, settle };
+}
+
+// Every render's (id, data, error, loading), so a stale value shown for a
+// single render between new deps and the reload cannot slip past.
+function mount(opts?: AsyncOptions) {
+  const req = requests();
+  const seen: { id: string; data: string | null; error: unknown; loading: boolean }[] = [];
+  const hook = renderHook(
+    ({ id }: { id: string }) => {
+      const r = useAsync(() => req.fetch(id), [id], opts);
+      seen.push({ id, data: r.data, error: r.error, loading: r.loading });
+      return r;
+    },
+    { initialProps: { id: "a" } },
+  );
+  return { ...req, ...hook, seen };
+}
+
+describe("useAsync", () => {
+  it("never shows one id's result while another id loads", async () => {
+    const h = mount();
+    await h.settle(0, { ok: "server a" });
+    expect(h.result.current.data).toBe("server a");
+
+    h.rerender({ id: "b" });
+    const forB = h.seen.filter((s) => s.id === "b");
+    expect(forB.length).toBeGreaterThan(0);
+    expect(forB.filter((s) => s.data !== null || !s.loading)).toEqual([]);
+
+    await h.settle(1, { ok: "server b" });
+    expect(h.result.current).toMatchObject({ data: "server b", loading: false });
+  });
+
+  it("never shows one id's error for another id", async () => {
+    const h = mount();
+    await h.settle(0, { fail: new Error("a is gone") });
+    expect(h.result.current.error).toBeInstanceOf(Error);
+
+    h.rerender({ id: "b" });
+    const forB = h.seen.filter((s) => s.id === "b");
+    expect(forB.length).toBeGreaterThan(0);
+    expect(forB.filter((s) => s.error !== null)).toEqual([]);
+  });
+
+  it("keeps the data through a reload of the same id", async () => {
+    const h = mount();
+    await h.settle(0, { ok: "first read" });
+
+    act(() => h.result.current.reload());
+    expect(h.result.current).toMatchObject({ data: "first read", loading: true });
+
+    await h.settle(1, { ok: "second read" });
+    expect(h.result.current).toMatchObject({ data: "second read", loading: false });
+  });
+
+  it("keeps the data and reports the error when a reload of the same id fails", async () => {
+    const h = mount();
+    await h.settle(0, { ok: "first read" });
+
+    act(() => h.result.current.reload());
+    await h.settle(1, { fail: new Error("blip") });
+    expect(h.result.current.data).toBe("first read");
+    expect(h.result.current.error).toBeInstanceOf(Error);
+    expect(h.result.current.loading).toBe(false);
+  });
+
+  it("with keepPrevious keeps the last rows until the new ones arrive", async () => {
+    const h = mount({ keepPrevious: true });
+    await h.settle(0, { ok: "page 1" });
+
+    h.rerender({ id: "b" });
+    expect(h.result.current).toMatchObject({ data: "page 1", loading: true });
+
+    await h.settle(1, { ok: "page 2" });
+    expect(h.result.current).toMatchObject({ data: "page 2", loading: false });
+  });
+
+  it("drops a slow answer for an id it has moved past", async () => {
+    const h = mount();
+    h.rerender({ id: "b" });
+    await h.settle(1, { ok: "server b" });
+    await h.settle(0, { ok: "server a" });
+    expect(h.result.current.data).toBe("server b");
+  });
+});

panel/src/lib/hooks.ts

@@ -25,12 +25,33 @@ export interface AsyncState<T> {
   reload: () => void;
 }
 
+export interface AsyncOptions {
+  /** Keep showing the last result while new deps load, for a list whose deps
+   *  are its filter or page: the old rows stay put (each still acts on its own
+   *  item) instead of blanking to a spinner on every keystroke. */
+  keepPrevious?: boolean;
+}
+
+interface Settled<T> {
+  /** The producer this result came from; a new one means new deps. */
+  run: () => Promise<T>;
+  data: T | null;
+  error: unknown;
+  loading: boolean;
+}
+
 /** useAsync runs an async producer on mount and on demand, guarding against
- *  setState-after-unmount and out-of-order responses. */
-export function useAsync<T>(fn: () => Promise<T>, deps: unknown[] = []): AsyncState<T> {
-  const [data, setData] = useState<T | null>(null);
-  const [error, setError] = useState<unknown>(null);
-  const [loading, setLoading] = useState(true);
+ *  setState-after-unmount and out-of-order responses. A reload with the same
+ *  deps (polling, after a mutation) keeps the current data while it runs. New
+ *  deps start from nothing: the result of /servers/a is never shown as
+ *  /servers/b, whose buttons already act on b, not even for the one render
+ *  before the new request starts. */
+export function useAsync<T>(
+  fn: () => Promise<T>,
+  deps: unknown[] = [],
+  { keepPrevious = false }: AsyncOptions = {},
+): AsyncState<T> {
+  const [settled, setSettled] = useState<Settled<T> | null>(null);
   const seq = useRef(0);
 
   // eslint-disable-next-line react-hooks/exhaustive-deps
@@ -38,23 +59,23 @@ export function useAsync<T>(fn: () => Promise<T>, deps: unknown[] = []): AsyncSt
 
   const reload = useCallback(() => {
     const ticket = ++seq.current;
-    setLoading(true);
-    setError(null);
+    setSettled((s) => ({
+      run,
+      data: s?.run === run || keepPrevious ? (s?.data ?? null) : null,
+      error: null,
+      loading: true,
+    }));
     run().then(
       (d) => {
-        if (ticket === seq.current) {
-          setData(d);
-          setLoading(false);
-        }
+        if (ticket === seq.current) setSettled({ run, data: d, error: null, loading: false });
       },
       (e) => {
         if (ticket === seq.current) {
-          setError(e);
-          setLoading(false);
+          setSettled((s) => ({ run, data: s?.data ?? null, error: e, loading: false }));
         }
       },
     );
-  }, [run]);
+  }, [run, keepPrevious]);
 
   useEffect(() => {
     reload();
@@ -65,7 +86,15 @@ export function useAsync<T>(fn: () => Promise<T>, deps: unknown[] = []): AsyncSt
     };
   }, [reload]);
 
-  return { data, error, loading, reload };
+  // Checked at render: between new deps and the effect that reloads them the
+  // state still holds the old producer's result.
+  const current = settled?.run === run;
+  return {
+    data: current || keepPrevious ? (settled?.data ?? null) : null,
+    error: current ? settled.error : null,
+    loading: current ? settled.loading : true,
+    reload,
+  };
 }
 
 /** useUnsavedGuard asks the browser to confirm leaving the page (reload, tab