Wrong order for the down/0 migration when changing both a field's name and nullability

[ibarakaiev]

Versions

Elixir: 1.18.4
OPT: 27

Operating system

MacOS

Current Behavior

I was introducing AshStateMachine to a resource which had an existing optional status field, which auto-generated the following migration:

defmodule MyApp.Repo.Migrations.UpdateProducts do
  @moduledoc """
  Updates resources based on their most recent snapshots.

  This file was autogenerated with `mix ash_postgres.generate_migrations`
  """

  use Ecto.Migration

  def up do
    rename table(:products), :status, to: :state

    alter table(:products) do
      modify :state, :text, null: false
    end
  end

  def down do
    alter table(:products) do
      modify :status, :text, null: true
    end

    rename table(:product), :state, to: :status
  end
end

The down/0 migration here fails because it attempts to modify :status before :state is renamed to :status.

Reproduction

Have an existing resource with a nullable status field, then remove it, and introduce AshStateMachine (or just rename it to :state and make it nullable directly).

Expected Behavior

The correct order should be:

def down do
  alter table(:products) do
    modify :status, :text, null: true
  end

  rename table(:product), :state, to: :status
end

[zachdaniel]

Thanks for the report! PRs welcome as I likely won't have time to look into this soon.

[awerment]

I have a small, working fix. If nobody's picked this up yet, I would open a PR

@ibarakaiev I assume in your code snippet for the expected behavior you actually meant:

def down do
  alter table(:products) do
    modify :state, :text, null: true
  end

  rename table(:product), :state, to: :status
end

(:state instead of :status in modify)

[zachdaniel]

@awerment PR welcome 🙏