fix(client): avoid nil-cache panic in Client.RemoveData

constraint/pkg/client/client.go

@@ -617,8 +617,9 @@ func (c *Client) RemoveData(ctx context.Context, data interface{}) (*types.Respo
 
 		if cacher, ok := h.(handler.Cacher); ok {
 			cache := cacher.GetCache()
-
-			cache.Remove(relPath)
+			if cache != nil {
+				cache.Remove(relPath)
+			}
 		}
 	}
 

constraint/pkg/client/client_test.go

@@ -28,6 +28,14 @@ import (
 	"k8s.io/utils/ptr"
 )
 
+type nilCacheHandler struct {
+	*handlertest.Handler
+}
+
+func (h *nilCacheHandler) GetCache() handler.Cache {
+	return nil
+}
+
 func TestBackend_NewClient_InvalidTargetName(t *testing.T) {
 	tcs := []struct {
 		name      string
@@ -2134,3 +2142,16 @@ func TestClient_RemoveData_Cache(t *testing.T) {
 		})
 	}
 }
+
+func TestClient_RemoveData_NilCache(t *testing.T) {
+	h := &nilCacheHandler{
+		Handler: &handlertest.Handler{},
+	}
+
+	c := clienttest.New(t, client.Targets(h))
+
+	_, err := c.RemoveData(context.Background(), &handlertest.Object{Namespace: "foo"})
+	if err != nil {
+		t.Fatalf("got RemoveData() error = %v, want nil", err)
+	}
+}