feat: complete Task 7 - end-to-end integration and full test suite

cmd/api/handlers_test.go

@@ -154,4 +154,111 @@ func TestHandlerStationStatus(t *testing.T) {
 		t.Fatalf("failed to unmarshal response: %v", err)
 	}
 	t.Logf("station status response: %+v", resp)
-}
+}
+
+// TestHandlerRouteSearchIntegration tests the route search handler with a fully built graph,
+// verifying the cache-aware flow: handler → graph → route search → response.
+func TestHandlerRouteSearchIntegration(t *testing.T) {
+	h := newMockHandlerContext()
+
+	// Build a routing graph using the same pattern as TestFindRouteSuccess:
+	// stations with real edges and one synthetic transfer edge, plus city hub.
+	graph := routing.NewGraph()
+	graph.AddNode(&routing.Node{ID: "c1", Type: routing.NodeTypeCity, Name: "City Hub"})
+	graph.AddNode(&routing.Node{ID: "s1", Type: routing.NodeTypeStation, Name: "Moscow", CityCode: "c1"})
+	graph.AddNode(&routing.Node{ID: "s2", Type: routing.NodeTypeStation, Name: "Tula", CityCode: "c1"})
+	graph.AddNode(&routing.Node{ID: "s3", Type: routing.NodeTypeStation, Name: "Vladimir", CityCode: "c1"})
+
+	// Add synthetic edge: city hub <-> station Moscow (transfer)
+	graph.AddEdge(&routing.Edge{
+		From:       graph.Nodes()[0], // c1 city hub
+		To:         graph.Nodes()[1], // s1 Moscow
+		Kind:       routing.EdgeKindSynthetic,
+		Duration:   300,
+		Transport:  "train",
+		IsTransfer: true,
+	})
+	graph.AddEdge(&routing.Edge{
+		From:       graph.Nodes()[1], // s1 Moscow
+		To:         graph.Nodes()[0], // c1 city hub
+		Kind:       routing.EdgeKindSynthetic,
+		Duration:   300,
+		Transport:  "train",
+		IsTransfer: true,
+	})
+
+	// Add real edge: direct route Moscow → Tula
+	graph.AddEdge(&routing.Edge{
+		From:       graph.Nodes()[1], // s1 Moscow
+		To:         graph.Nodes()[2], // s2 Tula
+		Kind:       routing.EdgeKindReal,
+		Duration:   3600,
+		Transport:  "train",
+		IsTransfer: false,
+	})
+
+	// Add synthetic transfer edge: Tula → Vladimir (1 transfer)
+	graph.AddEdge(&routing.Edge{
+		From:       graph.Nodes()[2], // s2 Tula
+		To:         graph.Nodes()[3], // s3 Vladimir
+		Kind:       routing.EdgeKindSynthetic,
+		Duration:   1800,
+		Transport:  "train",
+		IsTransfer: true,
+	})
+
+	// Replace the router with our test graph
+	h.Router = graph
+
+	// Create request: from city c1 (Moscow) to city c1 (same city code)
+	req := httptest.NewRequest("POST", "/v1/routes/search", strings.NewReader(`{"from_city_id": "c1", "to_city_id": "c1", "date": "2026-08-15"}`))
+	req.Header.Set("Content-Type", "application/json")
+
+	rr := httptest.NewRecorder()
+	RouteSearch(h, rr, req)
+
+	if rr.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d", rr.Code)
+	}
+
+	var resp routeSearchResponse
+	if err := json.Unmarshal(rr.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("failed to unmarshal response: %v", err)
+	}
+	t.Logf("route search response: routes=%+v, count=%d", resp.Routes, resp.Count)
+
+	// With this graph, we should find a route with 1 transfer
+	if resp.Count == 0 {
+		t.Error("expected at least 1 route, got 0")
+	}
+}
+
+// TestHandlerRouteSearchNoRoute tests route search when origin/destination not in graph.
+func TestHandlerRouteSearchNoRoute(t *testing.T) {
+	h := newMockHandlerContext()
+
+	// Create graph with no relevant nodes, but add some so the handler can find
+	// the city IDs (otherwise handler returns 404 before route search)
+	graph := routing.NewGraph()
+	graph.AddNode(&routing.Node{ID: "c999", Type: routing.NodeTypeCity, Name: "City 999"})
+	graph.AddNode(&routing.Node{ID: "c888", Type: routing.NodeTypeCity, Name: "City 888"})
+	h.Router = graph
+
+	req := httptest.NewRequest("POST", "/v1/routes/search", strings.NewReader(`{"from_city_id": "c999", "to_city_id": "c888", "date": "2026-08-15"}`))
+	req.Header.Set("Content-Type", "application/json")
+
+	rr := httptest.NewRecorder()
+	RouteSearch(h, rr, req)
+
+	if rr.Code != http.StatusOK {
+		t.Errorf("expected status 200, got %d", rr.Code)
+	}
+
+	var resp routeSearchResponse
+	if err := json.Unmarshal(rr.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("failed to unmarshal response: %v", err)
+	}
+	if resp.Count != 0 {
+		t.Errorf("expected 0 routes, got %d", resp.Count)
+	}
+}