This module helps to store and load your GenServer state automatically.

Use it inside your GenServer like

defmodule MyGenServer do
  use GenServer
  use FileCache.GSHelper, [id: :my_state]
end

It will define two callbacks automatically for you, which will store the state when in the terminate/2 callback, and restore it in the init/1 callback

However, of course you can override them if you like. And implement the logic for storing and loading yourself. This is what the use FileCache.GSHelper id: :my_state will add under the hood

defmodule MyGenServer do
  use GenServer

  def start_link(), do: ...
  def init(args) do
    {:ok, FileCache.load(:my_state) || args}
  end

  def terminate(_reason, state) do
    FileCache.store(:my_state, state)
  end
end