improvement: add Igniter installer task

[ibarakaiev]

Contributor checklist

• Bug fixes include regression tests
• Features include unit/acceptance tests

This PR adds an Igniter installer which also checks whether AshPostgres is in use, and if so, installs the AshMoney.AshPostgresExtension as well as ex_money_sql.

When testing, everything works, but I am facing an issue that seems unrelated to this installer:

** (UndefinedFunctionError) function AshMoney.AshPostgresExtension.extension/0 is undefined (module AshMoney.AshPostgresExtension is not available)
    AshMoney.AshPostgresExtension.extension()
    (ash_postgres 2.0.12) lib/migration_generator/migration_generator.ex:205: anonymous fn/1 in AshPostgres.MigrationGenerator.create_extension_migrations/2
    (elixir 1.17.0) lib/enum.ex:1703: Enum."-map/2-lists^map/1-1-"/2
    (elixir 1.17.0) lib/enum.ex:1703: Enum."-map/2-lists^map/1-1-"/2
    (ash_postgres 2.0.12) lib/migration_generator/migration_generator.ex:203: anonymous fn/2 in AshPostgres.MigrationGenerator.create_extension_migrations/2
    (elixir 1.17.0) lib/enum.ex:1703: Enum."-map/2-lists^map/1-1-"/2
    (ash_postgres 2.0.12) lib/migration_generator/migration_generator.ex:52: AshPostgres.MigrationGenerator.generate/2
    (mix 1.17.0) lib/mix/task.ex:495: anonymous fn/3 in Mix.Task.run_task/5

It might be possible that it's actually related to it, so I'm marking the PR as draft until I figure out what's the issue.

[zachdaniel]

Won't have time to look into the error you mentioned today, LMK if you figure it out :)

[ibarakaiev]

Well, the problem seems to have gone away by itself. Maybe there was a hidden dependency issue. Marking as ready for review then!

[ibarakaiev]

The remaining dialyzer warning in CI is because of ash-project/igniter#19.

[ibarakaiev]

Another strange finding: running mix igniter.install ash_money twice leads to:

** (CaseClauseError) no case clause matching: #Sourceror.Zipper<
  [{:__aliases__, [trailing_comments: [], leading_comments: [], last: [line: 2, column: 43], line: 2, column: 28], [:AshMoney, :Types, :Money]}]
>
    (igniter 0.2.3) lib/code/common.ex:591: Igniter.Code.Common.within/2
    (igniter 0.2.3) lib/project/config.ex:162: Igniter.Project.Config.modify_configuration_code/5
    (igniter 0.2.3) lib/igniter.ex:710: Igniter.apply_func_with_zipper/3
    (igniter 0.2.3) lib/igniter.ex:160: Igniter.update_elixir_file/3
    (ash_money 0.1.9) lib/mix/tasks/ash_money.install.ex:15: Mix.Tasks.AshMoney.Install.igniter/2
    (elixir 1.17.0) lib/enum.ex:4423: anonymous fn/3 in Enum.reduce/3
    (elixir 1.17.0) lib/stream.ex:1879: anonymous fn/3 in Enumerable.Stream.reduce/3
    (elixir 1.17.0) lib/enum.ex:4858: Enumerable.List.reduce/3

which seems to be happening in Mix.Tasks.AshMoney.Install.configure_config/1 when config :ash, known_types: [...] already exists. However, changing append_new_to_list to prepend_new_to_list in the updater function for Igniter.Project.Config.configure/6 fixed the error. Not sure what's the deal there.

[zachdaniel]

append_new_to_list should be fixed now.

[ibarakaiev]

Should probably change the manual |> Igniter.add_task("deps.get") task to |> Igniter.apply_and_fetch_dependencies() if/once ash-project/igniter#28 is merged.

[zachdaniel]

Alright, check out the new info/2 callback and use that for orchestrating the things you want to orchestrate and I think that should solve a lot of problems.

[ibarakaiev]

The installer is now complete, pending ash-project/igniter#33.

[ibarakaiev]

Should we support "breakpoints" for Igniter.add_task/3? Otherwise, a scenario like this happens:

1. Run mix igniter.install ash_postgres,ash_money (with versions).
2. ash_postgres.install installs the "ash-functions" extension and adds a ash.codegen install_ash_postgres task.
3. ash_money.install installs AshMoney.AshPostgresExtension and adds a ash.codegen install_ash_money task.
4. All changes are commited and the tasks are only then being run, resulting in the following sequence:

• install_ash_postgres install both "ash-functions" and AshMoney.AshPostgresExtension in one migration.
• install_ash_money is still run, but produces nothing.

In my hobby project I also have a pipeline where ash_postgres, ash_money are installed, then some resources are created and ash.codegen setup_resources is added as a task, but all three steps gets squashed into one migration within install_ash_postgres while the other run with empty results.

[zachdaniel]

I think supporting things like checkpoints will make things very complicated relative to the current implementation. A simpler way to accomplish this would be to add a function in Ash.Igniter called add_codegen_task(name), that will either add the codegen task or update it to update the name argument to be old_name_and_new_name.

[zachdaniel]

Going to make one main change with this which is to use the installs option in the info/2 callback, which will handle the front-loading installation of any dependencies.

[zachdaniel]

🚀 Thank you for your contribution! 🚀

[zachdaniel]

Ah, right that was the complexity here, which is that it's installed conditionally. 🤔 🤔 🤔

[zachdaniel]

Okay, I've updated igniter such that it will only apply changes to the deps function when that function is called :)