enhance utilisation of postgres features

server/middleware/cache.go

@@ -1,18 +1,38 @@
 package middleware
 
 import (
-	"vctp/version"
 	"net/http"
+	"strings"
+	"time"
+	"vctp/version"
 )
 
 // CacheMiddleware sets the Cache-Control header based on the version.
 func CacheMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if version.Value == "dev" {
-			w.Header().Set("Cache-Control", "no-cache")
+			w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+			w.Header().Set("Pragma", "no-cache")
+			w.Header().Set("Expires", "0")
 		} else {
-			w.Header().Set("Cache-Control", "public, max-age=31536000")
+			cacheControl := "public, max-age=31536000"
+			if isVersionedAssetRequest(r) {
+				cacheControl += ", immutable"
+			}
+			w.Header().Set("Cache-Control", cacheControl)
+			w.Header().Set("Expires", time.Now().UTC().Add(365*24*time.Hour).Format(http.TimeFormat))
 		}
+		w.Header().Set("Vary", "Accept-Encoding")
 		next.ServeHTTP(w, r)
 	})
 }
+
+func isVersionedAssetRequest(r *http.Request) bool {
+	if r == nil {
+		return false
+	}
+	if r.URL.Query().Get("v") != "" {
+		return true
+	}
+	return strings.Contains(r.URL.Path, "@")
+}

server/middleware/cache_test.go

@@ -0,0 +1,83 @@
+package middleware
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"vctp/version"
+)
+
+func TestCacheMiddlewareDev(t *testing.T) {
+	orig := version.Value
+	version.Value = "dev"
+	defer func() { version.Value = orig }()
+
+	rr := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/assets/css/web3.css", nil)
+	h := CacheMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+
+	h.ServeHTTP(rr, req)
+
+	if got := rr.Header().Get("Cache-Control"); got != "no-cache, no-store, must-revalidate" {
+		t.Fatalf("unexpected Cache-Control: %q", got)
+	}
+	if got := rr.Header().Get("Pragma"); got != "no-cache" {
+		t.Fatalf("unexpected Pragma: %q", got)
+	}
+	if got := rr.Header().Get("Expires"); got != "0" {
+		t.Fatalf("unexpected Expires: %q", got)
+	}
+	if got := rr.Header().Get("Vary"); got != "Accept-Encoding" {
+		t.Fatalf("unexpected Vary: %q", got)
+	}
+}
+
+func TestCacheMiddlewareProd(t *testing.T) {
+	orig := version.Value
+	version.Value = "1.2.3"
+	defer func() { version.Value = orig }()
+
+	rr := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/assets/css/web3.css?v=1.2.3", nil)
+	h := CacheMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+
+	h.ServeHTTP(rr, req)
+
+	if got := rr.Header().Get("Cache-Control"); got != "public, max-age=31536000, immutable" {
+		t.Fatalf("unexpected Cache-Control: %q", got)
+	}
+	if rr.Header().Get("Expires") == "" {
+		t.Fatalf("expected Expires header")
+	}
+	if got := rr.Header().Get("Vary"); got != "Accept-Encoding" {
+		t.Fatalf("unexpected Vary: %q", got)
+	}
+	if got := rr.Header().Get("Pragma"); got != "" {
+		t.Fatalf("expected no Pragma in prod, got %q", got)
+	}
+}
+
+func TestCacheMiddlewareProdUnversionedStillCached(t *testing.T) {
+	orig := version.Value
+	version.Value = "1.2.3"
+	defer func() { version.Value = orig }()
+
+	rr := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, "/swagger/swagger-ui.css", nil)
+	h := CacheMiddleware(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+	}))
+
+	h.ServeHTTP(rr, req)
+
+	if got := rr.Header().Get("Cache-Control"); got != "public, max-age=31536000" {
+		t.Fatalf("unexpected Cache-Control: %q", got)
+	}
+	if rr.Header().Get("Expires") == "" {
+		t.Fatalf("expected Expires header")
+	}
+}