Ignore malformed direct map routes

src/features/flights-map/components/FlightsMapStartPage.test.tsx

@@ -476,6 +476,28 @@ describe("FlightsMapStartPage — C.4 integration", () => {
     expect(popups[1]!.content).toContain("https://www.aeroflot.ru/sb/app/ru-ru");
   });
 
+  it("does not draw malformed multi-hop direct routes when transfers are off", () => {
+    searchState.routes = [
+      { route: ["SVO", "LED"], isDirect: true },
+      { route: ["SVO", "AER", "LED"], isDirect: true },
+    ];
+    setMapFilter({
+      departure: "MOW",
+      arrival: "LED",
+      date: null,
+      showInternal: false,
+      showInternational: false,
+      showTransfers: false,
+    });
+
+    render(<FlightsMapStartPage />);
+
+    const polylines = lastMapCanvasProps!["polylines"] as Array<{ cityIds: string[] }>;
+    expect(polylines).toEqual([
+      expect.objectContaining({ cityIds: ["MOW", "LED"] }),
+    ]);
+  });
+
   it("does not render popups in spider mode (departure only)", () => {
     searchState.routes = [{ route: ["MOW", "LED"], isDirect: true }];
     render(<FlightsMapStartPage />);

src/features/flights-map/filterRoutes.test.ts

@@ -102,6 +102,49 @@ describe("filterRoutes — connections", () => {
   });
 });
 
+describe("filterRoutes — route mode without transfer-only toggle", () => {
+  it("drops malformed direct routes that contain intermediate cities", () => {
+    const routes: IFlightRoute[] = [
+      { route: ["SVO", "LED"], isDirect: true },
+      { route: ["SVO", "AER", "LED"], isDirect: true },
+      { route: ["SVO", "AER", "LED"], isDirect: false },
+    ];
+
+    const out = filterRoutes(
+      routes,
+      filter({ departure: "MOW", arrival: "LED", connections: false }),
+      d,
+    );
+
+    expect(out).toEqual([{ route: ["SVO", "LED"], isDirect: true }]);
+  });
+
+  it("keeps connecting routes in route mode when transfer-only toggle is active", () => {
+    const routes: IFlightRoute[] = [
+      { route: ["SVO", "LED"], isDirect: true },
+      { route: ["SVO", "AER", "LED"], isDirect: false },
+    ];
+
+    const out = filterRoutes(
+      routes,
+      filter({ departure: "MOW", arrival: "LED", connections: true }),
+      d,
+    );
+
+    expect(out).toEqual([{ route: ["SVO", "AER", "LED"], isDirect: false }]);
+  });
+
+  it("does not apply endpoint-direct filtering in spider mode", () => {
+    const routes: IFlightRoute[] = [
+      { route: ["SVO", "AER", "LED"], isDirect: true },
+    ];
+
+    const out = filterRoutes(routes, filter({ departure: "MOW" }), d);
+
+    expect(out).toEqual(routes);
+  });
+});
+
 describe("filterRoutes — airport-code normalization", () => {
   it("treats airport codes (SVO, JFK) as their city codes (MOW, NYC)", () => {
     const routes: IFlightRoute[] = [

src/features/flights-map/filterRoutes.ts

@@ -17,7 +17,10 @@ import type { IFlightRoute, IFlightsMapFilterState } from "./types.js";
 
 export function filterRoutes(
   routes: IFlightRoute[],
-  filter: Pick<IFlightsMapFilterState, "domestic" | "international" | "connections">,
+  filter: Pick<
+    IFlightsMapFilterState,
+    "departure" | "arrival" | "domestic" | "international" | "connections"
+  >,
   dictionaries: IDictionaries,
 ): IFlightRoute[] {
   const { domestic, international, connections } = filter;
@@ -32,6 +35,17 @@ export function filterRoutes(
     r.route.some((code) => dictionaries.otherCityCodes.has(toCityCode(code)));
 
   const hasConnections = (r: IFlightRoute): boolean => !r.isDirect;
+  const isEndpointDirectRoute = (r: IFlightRoute): boolean => {
+    if (!filter.departure || !filter.arrival) return true;
+    if (!r.isDirect) return false;
+
+    const normalized = r.route.map(toCityCode);
+    return (
+      normalized.length === 2 &&
+      normalized[0] === toCityCode(filter.departure) &&
+      normalized[1] === toCityCode(filter.arrival)
+    );
+  };
 
   const predicates: Array<(r: IFlightRoute) => boolean> = [];
 
@@ -39,6 +53,7 @@ export function filterRoutes(
   else if (international && !domestic) predicates.push(isInternational);
 
   if (connections) predicates.push(hasConnections);
+  else if (filter.arrival) predicates.push(isEndpointDirectRoute);
 
   if (predicates.length === 0) return routes;
   return routes.filter((r) => predicates.every((p) => p(r)));