phase3: HTTP server with converter, one-shot preview store, and middleware

internal/server/preview_store_test.go

@@ -0,0 +1,80 @@
+package server
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestPreviewStore_OneShot(t *testing.T) {
+	t.Parallel()
+
+	store := NewPreviewStore(time.Hour)
+	id := store.Put([]byte("<h1>Hello</h1>"), "text/html; charset=utf-8", "hello.html")
+
+	item, ok := store.Take(id)
+	if !ok {
+		t.Fatalf("expected first take to succeed")
+	}
+	if got := string(item.html); got != "<h1>Hello</h1>" {
+		t.Fatalf("unexpected html: %q", got)
+	}
+
+	if _, ok := store.Take(id); ok {
+		t.Fatalf("expected second take to miss")
+	}
+}
+
+func TestPreviewStore_TTL(t *testing.T) {
+	t.Parallel()
+
+	store := NewPreviewStore(10 * time.Millisecond)
+	id := store.Put([]byte("expired"), "text/html; charset=utf-8", "expired.html")
+
+	time.Sleep(30 * time.Millisecond)
+	store.cleanupExpired(time.Now())
+
+	if _, ok := store.Take(id); ok {
+		t.Fatalf("expected expired item to be removed")
+	}
+}
+
+func TestPreviewStore_Concurrent(t *testing.T) {
+	t.Parallel()
+
+	store := NewPreviewStore(time.Hour)
+	var wg sync.WaitGroup
+
+	for i := 0; i < 32; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			id := store.Put([]byte("payload"), "text/html; charset=utf-8", "payload.html")
+			store.Take(id)
+		}()
+	}
+
+	wg.Wait()
+}
+
+func TestPreviewStore_JanitorStopsWithContext(t *testing.T) {
+	t.Parallel()
+
+	store := NewPreviewStore(time.Hour)
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan struct{})
+
+	go func() {
+		store.janitor(ctx)
+		close(done)
+	}()
+
+	cancel()
+
+	select {
+	case <-done:
+	case <-time.After(time.Second):
+		t.Fatal("janitor did not stop after context cancellation")
+	}
+}