test(lib_core): it saves and return tasks

refs: #5

lib_sync_core/src/database.rs

@@ -69,7 +69,7 @@ impl<T: TaskPayload> TasksPage<T> {
 }
 
 pub trait TaskStorage<T: TaskPayload> {
-    async fn insert_tasks(&self, tasks: Vec<Task<T>>) -> crate::Result<()>;
+    async fn insert_tasks<'a, I: IntoIterator<Item=&'a Task<T>>>(&self, tasks: I) -> crate::Result<()>;
     fn get_tasks(&self, options: TaskStatus) -> impl Stream<Item = crate::Result<Task<T>>>;
 
     async fn get_paginated_tasks(&self, page: &TaskPagination) -> crate::Result<TasksPage<T>>;