Pre-fill schedule form from popular request query params

Add buildSchedulePopularRequestQueryParams to convert Route/RouteWithBack
popular requests into URL search params. ScheduleStartPage now reads
departure/arrival/return from query params to initialize form state, and
the popular request click handler navigates with appropriate params for
both Schedule and Onlineboard request types.

src/features/schedule/components/ScheduleStartPage.test.tsx

@@ -0,0 +1,155 @@
+/**
+ * Tests for ScheduleStartPage component.
+ *
+ * Verifies query param building from popular requests and
+ * form state initialization from URL search params.
+ *
+ * @vitest-environment jsdom
+ */
+
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import { ScheduleStartPage, buildSchedulePopularRequestQueryParams } from "./ScheduleStartPage.js";
+import type { PopularRequest } from "@/features/popular-requests/types.js";
+
+const mockNavigate = vi.fn();
+let mockSearchParams = new URLSearchParams();
+
+vi.mock("@modern-js/runtime/router", () => ({
+  useNavigate: () => mockNavigate,
+  useParams: () => ({ lang: "ru" }),
+  useSearchParams: () => [mockSearchParams],
+  Link: ({ children, to, ...props }: { children: React.ReactNode; to: string; className?: string; [k: string]: unknown }) => (
+    <a href={to} {...props}>{children}</a>
+  ),
+}));
+
+vi.mock("@/i18n/provider.js", () => ({
+  useTranslation: () => ({
+    t: (key: string) => key,
+  }),
+}));
+
+vi.mock("@/features/popular-requests/components/PopularRequestsPanel.js", () => ({
+  PopularRequestsPanel: ({ onRequestClick }: { onRequestClick?: (r: PopularRequest) => void }) => (
+    <div data-testid="popular-requests">
+      <button
+        data-testid="popular-click-route"
+        onClick={() => onRequestClick?.({ mode: "Route", departure: "SVO", arrival: "LED", type: "Schedule" })}
+      >
+        Route
+      </button>
+      <button
+        data-testid="popular-click-onlineboard"
+        onClick={() => onRequestClick?.({ mode: "Departure", departure: "LED", type: "Onlineboard" })}
+      >
+        Onlineboard
+      </button>
+    </div>
+  ),
+}));
+
+vi.mock("@/features/online-board/components/OnlineBoardStartPage.js", () => ({
+  buildPopularRequestQueryParams: (request: PopularRequest) => {
+    const params = new URLSearchParams();
+    if (request.mode === "Departure") {
+      params.set("tab", "route");
+      params.set("departure", (request as { departure: string }).departure);
+    }
+    return params;
+  },
+}));
+
+vi.mock("@/shared/hooks/useCitySearch.js", () => ({
+  useCitySearch: () => ({ suggestions: [], search: vi.fn() }),
+}));
+
+vi.mock("@/ui/layout/SearchHistory.js", () => ({
+  SearchHistory: () => <div data-testid="search-history" />,
+}));
+
+// ---------------------------------------------------------------------------
+// Pure function: buildSchedulePopularRequestQueryParams
+// ---------------------------------------------------------------------------
+
+describe("buildSchedulePopularRequestQueryParams", () => {
+  it("builds params for Route mode with departure and arrival", () => {
+    const request: PopularRequest = {
+      mode: "Route",
+      departure: "SVO",
+      arrival: "LED",
+      type: "Schedule",
+    };
+    const params = buildSchedulePopularRequestQueryParams(request);
+    expect(params.get("departure")).toBe("SVO");
+    expect(params.get("arrival")).toBe("LED");
+    expect(params.has("return")).toBe(false);
+  });
+
+  it("builds params for RouteWithBack mode with return flag", () => {
+    const request: PopularRequest = {
+      mode: "RouteWithBack",
+      departure: "SVO",
+      arrival: "LED",
+      type: "Schedule",
+    };
+    const params = buildSchedulePopularRequestQueryParams(request);
+    expect(params.get("departure")).toBe("SVO");
+    expect(params.get("arrival")).toBe("LED");
+    expect(params.get("return")).toBe("true");
+  });
+
+  it("returns empty params for non-route modes", () => {
+    const request: PopularRequest = {
+      mode: "Arrival",
+      arrival: "VKO",
+      type: "Onlineboard",
+    };
+    const params = buildSchedulePopularRequestQueryParams(request);
+    expect(params.toString()).toBe("");
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Component tests
+// ---------------------------------------------------------------------------
+
+describe("ScheduleStartPage", () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    mockSearchParams = new URLSearchParams();
+  });
+
+  it("renders the start page", () => {
+    render(<ScheduleStartPage />);
+    expect(screen.getByTestId("schedule-start")).toBeTruthy();
+  });
+
+  it("navigates to schedule page on Schedule-type popular request click", () => {
+    render(<ScheduleStartPage />);
+    fireEvent.click(screen.getByTestId("popular-click-route"));
+    expect(mockNavigate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        pathname: "/ru/schedule",
+        search: expect.stringContaining("departure=SVO"),
+      }),
+    );
+  });
+
+  it("navigates to onlineboard on Onlineboard-type popular request click", () => {
+    render(<ScheduleStartPage />);
+    fireEvent.click(screen.getByTestId("popular-click-onlineboard"));
+    expect(mockNavigate).toHaveBeenCalledWith(
+      expect.objectContaining({
+        pathname: "/ru/online-board",
+      }),
+    );
+  });
+
+  it("initializes form from search params", () => {
+    mockSearchParams = new URLSearchParams("departure=SVO&arrival=LED&return=true");
+    render(<ScheduleStartPage />);
+    const roundTripCheckbox = screen.getByTestId("round-trip-toggle");
+    expect((roundTripCheckbox as HTMLInputElement).checked).toBe(true);
+  });
+});

src/features/schedule/components/ScheduleStartPage.tsx

@@ -8,7 +8,7 @@
  */
 
 import { type FC, useState, useCallback, type FormEvent } from "react";
-import { useNavigate, useParams } from "@modern-js/runtime/router";
+import { useNavigate, useParams, useSearchParams } from "@modern-js/runtime/router";
 import { Calendar } from "primereact/calendar";
 import { Slider, type SliderChangeEvent } from "primereact/slider";
 import { AutoComplete, type AutoCompleteCompleteEvent } from "primereact/autocomplete";
@@ -19,6 +19,7 @@ import { PageTabs } from "@/ui/layout/PageTabs.js";
 import { SearchHistory } from "@/ui/layout/SearchHistory.js";
 import { PopularRequestsPanel } from "@/features/popular-requests/components/PopularRequestsPanel.js";
 import type { PopularRequest } from "@/features/popular-requests/types.js";
+import { buildPopularRequestQueryParams } from "@/features/online-board/components/OnlineBoardStartPage.js";
 import { buildScheduleUrl } from "../url.js";
 import "./ScheduleStartPage.scss";
 
@@ -41,21 +42,42 @@ function addDays(base: Date, days: number): Date {
   return result;
 }
 
+/**
+ * Build URL search params for a schedule-type popular request.
+ *
+ * Only Route and RouteWithBack modes produce params; other modes
+ * return empty params (they belong to the online board).
+ */
+export function buildSchedulePopularRequestQueryParams(
+  request: PopularRequest,
+): URLSearchParams {
+  const params = new URLSearchParams();
+  if (request.mode === "Route" || request.mode === "RouteWithBack") {
+    params.set("departure", request.departure);
+    params.set("arrival", request.arrival);
+    if (request.mode === "RouteWithBack") {
+      params.set("return", "true");
+    }
+  }
+  return params;
+}
+
 export const ScheduleStartPage: FC = () => {
   const navigate = useNavigate();
   const { t } = useTranslation();
   const routeParams = useParams<{ lang: string }>();
   const lang = routeParams.lang ?? "ru";
+  const [searchParams] = useSearchParams();
 
   const today = new Date();
 
-  const [departureAirport, setDepartureAirport] = useState<CitySuggestion | string>("");
-  const [arrivalAirport, setArrivalAirport] = useState<CitySuggestion | string>("");
+  const [departureAirport, setDepartureAirport] = useState<CitySuggestion | string>(searchParams.get("departure") ?? "");
+  const [arrivalAirport, setArrivalAirport] = useState<CitySuggestion | string>(searchParams.get("arrival") ?? "");
   const [dateFrom, setDateFrom] = useState<Date | null>(today);
   const [dateTo, setDateTo] = useState<Date | null>(addDays(today, 7));
   const [timeRange, setTimeRange] = useState<[number, number]>([0, 1440]);
   const [directOnly, setDirectOnly] = useState(false);
-  const [isRoundTrip, setIsRoundTrip] = useState(false);
+  const [isRoundTrip, setIsRoundTrip] = useState(searchParams.get("return") === "true");
   const [returnDateFrom, setReturnDateFrom] = useState<Date | null>(addDays(today, 7));
   const [returnDateTo, setReturnDateTo] = useState<Date | null>(addDays(today, 14));
   const [returnTimeRange, setReturnTimeRange] = useState<[number, number]>([0, 1440]);
@@ -124,9 +146,26 @@ export const ScheduleStartPage: FC = () => {
     [departureAirport, arrivalAirport, dateFrom, dateTo, timeRange, directOnly, isRoundTrip, returnDateFrom, returnDateTo, returnTimeRange, navigate, lang],
   );
 
-  const handlePopularRequestClick = useCallback((_request: PopularRequest) => {
-    // Navigation handled by PopularRequestItem internally
-  }, []);
+  const handlePopularRequestClick = useCallback(
+    (request: PopularRequest) => {
+      if (request.type === "Onlineboard") {
+        const params = buildPopularRequestQueryParams(request);
+        navigate({
+          pathname: `/${lang}/online-board`,
+          search: params.toString(),
+        });
+        return;
+      }
+
+      // Schedule-type: build params and navigate to schedule with pre-fill
+      const params = buildSchedulePopularRequestQueryParams(request);
+      navigate({
+        pathname: `/${lang}/schedule`,
+        search: params.toString(),
+      });
+    },
+    [navigate, lang],
+  );
 
   const scheduleFilter = (
     <form