Reset Commanded projections (domain specific)

reset_projections.ex

defmodule Mix.Tasks.ResetProjections do
  @moduledoc """
  Reset all system projects from events
  """
  use Mix.Task

  @projection_modules ~w(
    Ivrl.Tournaments.Projectors.Tournament
    Ivrl.Teams.Projectors.Team
    Ivrl.Players.Projectors.Player
    Ivrl.Matches.Projectors.Match
  )

  @projection_tables ~w(
    matches
    players
    team_players
    teams
    tournament_teams
    tournaments
    projection_versions
  )

  alias EventStore.Config.Store, as: ConfigStore
  alias Ivrl.Repo

  def run(_) do
    ensure_started()

    IO.puts("Truncating projection tables")
    truncate_tables()

    IO.puts("Restarting subscriptions")
    delete_subscriptions()

    IO.puts("Projections ready to re-populate")
  end

  defp truncate_tables do
    "TRUNCATE #{Enum.join(@projection_tables, ",")} RESTART IDENTITY CASCADE"
    |> Repo.query!()
  end

  defp delete_subscriptions do
    Enum.map(@projection_modules, &Ivrl.EventStore.delete_all_streams_subscription/1)
  end

  defp ensure_started do
    [:postgrex, :ecto]
    |> Enum.each(&Application.ensure_all_started/1)

    Ivrl.Repo.start_link()
    ConfigStore.start_link([])
    Ivrl.EventStore.start_link()
  end
end