Merge pull request #261 from woutslakhorst/master

memcached: fix Delete and Get for missing items

store/memcache/memcache.go

@@ -50,6 +50,9 @@ func NewMemcache(client MemcacheClientInterface, options ...lib_store.Option) *M
 func (s *MemcacheStore) Get(_ context.Context, key any) (any, error) {
 	item, err := s.client.Get(key.(string))
 	if err != nil {
+		if errors.Is(err, memcache.ErrCacheMiss) {
+			return nil, lib_store.NotFoundWithCause(err)
+		}
 		return nil, err
 	}
 	if item == nil {
@@ -63,6 +66,9 @@ func (s *MemcacheStore) Get(_ context.Context, key any) (any, error) {
 func (s *MemcacheStore) GetWithTTL(_ context.Context, key any) (any, time.Duration, error) {
 	item, err := s.client.Get(key.(string))
 	if err != nil {
+		if errors.Is(err, memcache.ErrCacheMiss) {
+			return nil, 0, lib_store.NotFoundWithCause(err)
+		}
 		return nil, 0, err
 	}
 	if item == nil {
@@ -159,7 +165,11 @@ func (s *MemcacheStore) addKeyToTagValue(tagKey string, key any) error {
 
 // Delete removes data from Memcache for given key identifier
 func (s *MemcacheStore) Delete(_ context.Context, key any) error {
-	return s.client.Delete(key.(string))
+	err := s.client.Delete(key.(string))
+	if errors.Is(err, memcache.ErrCacheMiss) {
+		return nil
+	}
+	return err
 }
 
 // Invalidate invalidates some cache data in Memcache for given options

store/memcache/memcache_test.go

@@ -51,6 +51,27 @@ func TestMemcacheGet(t *testing.T) {
 	assert.Equal(t, cacheValue, value)
 }
 
+func TestMemcacheGetWithMissingItem(t *testing.T) {
+	// Given
+	ctrl := gomock.NewController(t)
+
+	ctx := context.Background()
+
+	cacheKey := "my-key"
+
+	client := NewMockMemcacheClientInterface(ctrl)
+	client.EXPECT().Get(cacheKey).Return(nil, memcache.ErrCacheMiss)
+
+	store := NewMemcache(client, lib_store.WithExpiration(3*time.Second))
+
+	// When
+	value, err := store.Get(ctx, cacheKey)
+
+	// Then
+	assert.ErrorIs(t, err, lib_store.NotFound{})
+	assert.Nil(t, value)
+}
+
 func TestMemcacheGetWhenError(t *testing.T) {
 	// Given
 	ctrl := gomock.NewController(t)
@@ -109,15 +130,15 @@ func TestMemcacheGetWithTTLWhenMissingItem(t *testing.T) {
 	cacheKey := "my-key"
 
 	client := NewMockMemcacheClientInterface(ctrl)
-	client.EXPECT().Get(cacheKey).Return(nil, nil)
+	client.EXPECT().Get(cacheKey).Return(nil, memcache.ErrCacheMiss)
 
 	store := NewMemcache(client, lib_store.WithExpiration(3*time.Second))
 
 	// When
 	value, ttl, err := store.GetWithTTL(ctx, cacheKey)
 
 	// Then
-	assert.NotNil(t, err)
+	assert.ErrorIs(t, err, lib_store.NotFound{})
 	assert.Nil(t, value)
 	assert.Equal(t, 0*time.Second, ttl)
 }
@@ -296,6 +317,26 @@ func TestMemcacheDelete(t *testing.T) {
 	assert.Nil(t, err)
 }
 
+func TestMemcacheDeleteWithMissingItem(t *testing.T) {
+	// Given
+	ctrl := gomock.NewController(t)
+
+	ctx := context.Background()
+
+	cacheKey := "my-key"
+
+	client := NewMockMemcacheClientInterface(ctrl)
+	client.EXPECT().Delete(cacheKey).Return(memcache.ErrCacheMiss)
+
+	store := NewMemcache(client)
+
+	// When
+	err := store.Delete(ctx, cacheKey)
+
+	// Then
+	assert.Nil(t, err)
+}
+
 func TestMemcacheDeleteWhenError(t *testing.T) {
 	// Given
 	ctrl := gomock.NewController(t)