fixed item expiration behavior in lru

Author: Code-Hex

lru/lru.go

@@ -27,7 +27,7 @@ func NewCacheWithCap[K comparable, V any](cap int) *Cache[K, V] {
 	return &Cache[K, V]{
 		cap:   cap,
 		list:  list.New(),
-		items: make(map[K]*list.Element),
+		items: make(map[K]*list.Element, cap),
 	}
 }
 
@@ -75,7 +75,8 @@ func (c *Cache[K, V]) Keys() []K {
 	defer c.mu.RUnlock()
 	keys := make([]K, 0, len(c.items))
 	for ent := c.list.Back(); ent != nil; ent = ent.Prev() {
-		keys = append(keys, ent.Value.(*cache.Item[K, V]).Key)
+		item := ent.Value.(*cache.Item[K, V])
+		keys = append(keys, item.Key)
 	}
 	return keys
 }
@@ -100,8 +101,12 @@ func (c *Cache[K, V]) Delete(key K) {
 func (c *Cache[K, V]) Contains(key K) bool {
 	c.mu.RLock()
 	defer c.mu.RUnlock()
-	_, ok := c.items[key]
-	return ok
+	e, ok := c.items[key]
+	if !ok {
+		return false
+	}
+	item := e.Value.(*cache.Item[K, V])
+	return !item.HasExpired()
 }
 
 func (c *Cache[K, V]) deleteOldest() {

lru/lru_internal_test.go

@@ -0,0 +1,69 @@
+package lru
+
+import (
+	"testing"
+	"time"
+
+	cache "github.com/Code-Hex/go-generics-cache"
+)
+
+func TestContains(t *testing.T) {
+	t.Run("without expiration", func(t *testing.T) {
+		cache := NewCache[string, int]()
+		cache.Set("foo", 1)
+		cache.Set("bar", 2)
+		cache.Set("baz", 3)
+		for _, key := range []string{
+			"foo",
+			"bar",
+			"baz",
+		} {
+			if !cache.Contains(key) {
+				t.Errorf("not found: %s", key)
+			}
+		}
+		if cache.Contains("not found") {
+			t.Errorf("found")
+		}
+	})
+
+	t.Run("with expiration", func(t *testing.T) {
+		c := NewCache[string, int]()
+		key := "foo"
+		exp := time.Hour
+		c.Set(key, 1, cache.WithExpiration(exp))
+		// modify directly
+		e, ok := c.items[key]
+		if !ok {
+			t.Fatal("unexpected not found key")
+		}
+		item := e.Value.(*cache.Item[string, int])
+		item.CreatedAt = time.Now().Add(-2 * exp)
+
+		if c.Contains(key) {
+			t.Errorf("found")
+		}
+	})
+}
+
+func TestGet(t *testing.T) {
+	c := NewCache[string, int]()
+	key := "foo"
+	exp := time.Hour
+	c.Set(key, 1, cache.WithExpiration(exp))
+	_, ok := c.Get(key)
+	if !ok {
+		t.Fatal("unexpected not found")
+	}
+	// modify directly
+	e, ok := c.items[key]
+	if !ok {
+		t.Fatal("unexpected not found key")
+	}
+	item := e.Value.(*cache.Item[string, int])
+	item.CreatedAt = time.Now().Add(-2 * exp)
+	_, ok2 := c.Get(key)
+	if ok2 {
+		t.Fatal("unexpected found (expired)")
+	}
+}

lru/lru_test.go

@@ -43,22 +43,6 @@ func TestSet(t *testing.T) {
 	}
 }
 
-func TestContains(t *testing.T) {
-	cache := lru.NewCache[string, int]()
-	cache.Set("foo", 1)
-	cache.Set("bar", 2)
-	cache.Set("baz", 3)
-	for _, key := range []string{
-		"foo",
-		"bar",
-		"baz",
-	} {
-		if !cache.Contains(key) {
-			t.Errorf("not found: %s", key)
-		}
-	}
-}
-
 func TestDelete(t *testing.T) {
 	cache := lru.NewCacheWithCap[string, int](1)
 	cache.Set("foo", 1)