Fix back-to-host-details button on report details page (#39727) (#45238)

Resolves #39727 

Fixed bug on QueryDetailsPage's backPath() implementation, so the "Back
to host details" button does not followed the stale filteredQueriesPath
set when the user previously visited the reports page.

frontend/pages/queries/details/QueryDetailsPage/QueryDetailsPage.tests.tsx

@@ -0,0 +1,113 @@
+import React from "react";
+import { screen } from "@testing-library/react";
+import { http, HttpResponse } from "msw";
+
+import {
+  createCustomRenderer,
+  baseUrl,
+  createMockRouter,
+} from "test/test-utils";
+import mockServer from "test/mock-server";
+import createMockUser from "__mocks__/userMock";
+import createMockConfig from "__mocks__/configMock";
+import createMockSchedulableQuery from "__mocks__/scheduleableQueryMock";
+import createMockQueryReport from "__mocks__/queryReportMock";
+
+import QueryDetailsPage from "./QueryDetailsPage";
+
+// Render BackButton as a button exposing its `path` prop so we can assert on the
+// computed back URL without depending on react-router's browserHistory.
+jest.mock("components/BackButton", () => ({
+  __esModule: true,
+  default: ({ text, path }: { text: string; path?: string }) => (
+    <button type="button" data-testid="back-button" data-path={path ?? ""}>
+      {text}
+    </button>
+  ),
+}));
+
+const QUERY_ID = 1;
+const HOST_ID = 42;
+const FILTERED_QUERIES_PATH = "/queries/manage?fleet_id=1";
+
+const setupQueryHandlers = () => {
+  mockServer.use(
+    http.get(baseUrl(`/reports/${QUERY_ID}`), () =>
+      HttpResponse.json({
+        query: createMockSchedulableQuery({ id: QUERY_ID, team_id: null }),
+      })
+    ),
+    http.get(baseUrl(`/reports/${QUERY_ID}/report`), () =>
+      HttpResponse.json(
+        createMockQueryReport({ query_id: QUERY_ID, results: [] })
+      )
+    )
+  );
+};
+
+const createProps = (hostId?: number) => ({
+  router: createMockRouter(),
+  params: { id: String(QUERY_ID) },
+  location: {
+    pathname: `/reports/${QUERY_ID}`,
+    search: hostId !== undefined ? `?host_id=${hostId}` : "",
+    query: hostId !== undefined ? { host_id: String(hostId) } : {},
+  },
+});
+
+const baseAppContext = {
+  isGlobalAdmin: true,
+  isOnGlobalTeam: true,
+  // Free tier short-circuits useTeamIdParam's redirect logic when no fleet_id is set,
+  // keeping the test focused on backPath() rather than team reconciliation.
+  isFreeTier: true,
+  isPremiumTier: false,
+  currentUser: createMockUser({ global_role: "admin" }),
+  config: createMockConfig(),
+  availableTeams: [],
+};
+
+const renderPage = (
+  appOverrides: { filteredQueriesPath?: string } = {},
+  hostId?: number
+) => {
+  const render = createCustomRenderer({
+    withBackendMock: true,
+    context: { app: { ...baseAppContext, ...appOverrides } },
+  });
+  render(<QueryDetailsPage {...(createProps(hostId) as any)} />);
+  return screen.findByTestId("back-button");
+};
+
+describe("QueryDetailsPage - back navigation", () => {
+  beforeEach(() => setupQueryHandlers());
+
+  it.each([
+    {
+      name: "hostId wins over filteredQueriesPath",
+      app: { filteredQueriesPath: FILTERED_QUERIES_PATH },
+      hostId: HOST_ID,
+      expectText: "Back to host details",
+      expectPathContains: `/hosts/${HOST_ID}/details`,
+    },
+    {
+      name: "falls back to filteredQueriesPath when no hostId",
+      app: { filteredQueriesPath: FILTERED_QUERIES_PATH },
+      hostId: undefined,
+      expectText: "Back to reports",
+      expectPathContains: FILTERED_QUERIES_PATH,
+    },
+    {
+      name:
+        "falls back to manage reports when neither hostId nor filteredQueriesPath is set",
+      app: {},
+      hostId: undefined,
+      expectText: "Back to reports",
+      expectPathContains: "/reports/manage",
+    },
+  ])("$name", async ({ app, hostId, expectText, expectPathContains }) => {
+    const back = await renderPage(app, hostId);
+    expect(back).toHaveTextContent(expectText);
+    expect(back.getAttribute("data-path")).toContain(expectPathContains);
+  });
+});

frontend/pages/queries/details/QueryDetailsPage/QueryDetailsPage.tsx

@@ -251,15 +251,14 @@ const QueryDetailsPage = ({
       isGlobalTechnician ||
       isTeamTechnician;
 
-    // Function instead of constant eliminates race condition with filteredQueriesPath
     const backPath = () => {
-      if (filteredQueriesPath) return filteredQueriesPath;
-
       if (hostId)
         return getPathWithQueryParams(
           PATHS.HOST_DETAILS(hostId, currentTeamId)
         );
 
+      if (filteredQueriesPath) return filteredQueriesPath;
+
       return getPathWithQueryParams(PATHS.MANAGE_REPORTS, {
         fleet_id: currentTeamId,
       });