Hi,

I want some help in understanding where the following magic is coming from. Please see the code below. In the second test below, the line Gamestatus.change_newplayersallowed(false, "game-1234") correctly changes the value of newplayersallowed to false. I know this because, one, the tests passes and, two, the output of IO.inspect is false. However, after the test is completed, when I check the value of newplayersallowed using psql, the value of newplayersallowed is true. So it appears that the change made by function Gamestatus.change_newplayersallowed(false, "game-1234") is reverted to the value before that change. How does Elixir/Phoenix know which changes to revert? Where can I read about which changes to the database within tests will be reverted?

Thank you.

defmodule Games.GamestatusTest do
  use GamesWeb.ConnCase
  # use ExUnit.Case

  alias Games.Gamestatus


  test "Returns the correct newplayerallowed status" do
    assert Gamestatus.newplayersallowed?("game-1234") == true
  end

  test "Updates the newplayersallowed status" do
    Gamestatus.change_newplayersallowed(false, "game-1234")
    {status, _msg} = Gamestatus.newplayersallowed?("game-1234")
    IO.inspect(status, label: "newplayersallowed")
    assert status == false
  end


end ## end module

The following is the code for the function Gamestatus.change_newplayersallowed.

  @doc"""
  Change newplayersallowed to `set_to_val` for the given gameid
  """
  def change_newplayersallowed(set_to_val, gameid) do
    sql = "UPDATE gamesstatus SET newplayersallowed = $1" <>
            " WHERE gameid = $2;"

    Ecto.Adapters.SQL.query(
      Games.Repo,
      sql,
      [set_to_val, gameid]
    )

  end