fix(#76): report request-scoped data freshness

internal/web/freshness_test.go

@@ -0,0 +1,72 @@
+package web
+
+import (
+	"database/sql"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/AmanTahiliani/box-box/internal/api"
+	_ "modernc.org/sqlite"
+)
+
+func TestOpenF1HandlerReportsFreshThenStaleSuccess(t *testing.T) {
+	year := time.Now().Year()
+	upstream := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_, _ = fmt.Fprintf(w, `[{"meeting_key":1,"meeting_name":"British Grand Prix","year":%d}]`, year)
+	}))
+	client := api.NewOpenF1Client(upstream.URL, time.Second)
+	t.Cleanup(func() { _ = client.Close() })
+	server := NewServer(client, 0, nil)
+	cacheKey := fmt.Sprintf("%s/v1/meetings?year=%d", upstream.URL, year)
+	requestURL := fmt.Sprintf("/api/v1/meetings?year=%d&source=openf1", year)
+	defer func() {
+		// Keep the shared application cache clean even if this test fails.
+		db, err := sql.Open("sqlite", api.DefaultCacheDBPath()+"?_busy_timeout=5000")
+		if err == nil {
+			_, _ = db.Exec(`DELETE FROM cache WHERE key = ?`, cacheKey)
+			_ = db.Close()
+		}
+	}()
+
+	fresh := httptest.NewRecorder()
+	server.handleMeetings(fresh, httptest.NewRequest(http.MethodGet, requestURL, nil))
+	if fresh.Code != http.StatusOK || fresh.Header().Get(dataSourceHeader) != "openf1" || fresh.Header().Get(dataFreshnessHeader) != "fresh" {
+		t.Fatalf("fresh response status/metadata = %d %q/%q body=%s", fresh.Code, fresh.Header().Get(dataSourceHeader), fresh.Header().Get(dataFreshnessHeader), fresh.Body.String())
+	}
+
+	db, err := sql.Open("sqlite", api.DefaultCacheDBPath()+"?_busy_timeout=5000")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := db.Exec(`UPDATE cache SET created_at = ? WHERE key = ?`, time.Now().Add(-48*time.Hour).Unix(), cacheKey); err != nil {
+		_ = db.Close()
+		t.Fatal(err)
+	}
+	_ = db.Close()
+	upstream.Close()
+
+	stale := httptest.NewRecorder()
+	server.handleMeetings(stale, httptest.NewRequest(http.MethodGet, requestURL, nil))
+	if stale.Code != http.StatusOK || stale.Header().Get(dataSourceHeader) != "openf1" || stale.Header().Get(dataFreshnessHeader) != "stale" {
+		t.Fatalf("stale response status/metadata = %d %q/%q body=%s", stale.Code, stale.Header().Get(dataSourceHeader), stale.Header().Get(dataFreshnessHeader), stale.Body.String())
+	}
+}
+
+func TestFreshnessHeadersAreExposedToBrowserClients(t *testing.T) {
+	handler := withCORS(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		markDataResponse(w, "local", "partial")
+		writeJSON(w, map[string]bool{"ok": true})
+	}))
+	recorder := httptest.NewRecorder()
+	handler.ServeHTTP(recorder, httptest.NewRequest(http.MethodGet, "/api/v1/test", nil))
+
+	if got := recorder.Header().Get("Access-Control-Expose-Headers"); got != dataSourceHeader+", "+dataFreshnessHeader {
+		t.Fatalf("exposed headers = %q", got)
+	}
+	if recorder.Header().Get(dataSourceHeader) != "local" || recorder.Header().Get(dataFreshnessHeader) != "partial" {
+		t.Fatalf("data metadata = %q/%q", recorder.Header().Get(dataSourceHeader), recorder.Header().Get(dataFreshnessHeader))
+	}
+}