Do a compile-time check to make sure that the configured token_resource is an Ash.Resource

[simpers]

Issue

During a refactor of the auth resources, the tokens.token_resource field was not updated properly on my user resource, and so I ended up getting a very vague :error result when trying to create tokens, without any other context. It was caused by the module not existing, but the current checks only check that the value configured is an atom.

Errors

Initial error when trying to log in:

[error] | file=gen_server.erl line=2474 mfa=:gen_server.error_info/8 [22:44:23.824]: GenServer #PID<0.1271.0> terminating
** (MatchError) no match of right hand side value: :error
    (ash_authentication 4.0.1) lib/ash_authentication/strategies/password/sign_in_preparation.ex:117: AshAuthentication.Strategy.Password.SignInPreparation.generate_token/3
    (ash_authentication 4.0.1) lib/ash_authentication/strategies/password/sign_in_preparation.ex:44: anonymous fn/3 in AshAuthentication.Strategy.Password.SignInPreparation.prepare/3
    (ash 3.2.4) lib/ash/actions/read/read.ex:2097: anonymous fn/2 in Ash.Actions.Read.run_after_action/2
    (elixir 1.17.2) lib/enum.ex:4858: Enumerable.List.reduce/3
    (elixir 1.17.2) lib/enum.ex:2585: Enum.reduce_while/3
    ...

After adding some logging, I got this error:

[error] | file=lib/ash_authentication/jwt.ex line=119 mfa=AshAuthentication.Jwt.token_for_user/3 [23:26:09.713]: Failed to generate token for user: "Module `Lpe.Resources.Token` is not an Ash resource"

Improvement

Improved compile-time validation of the token_resource option of the tokens DSL by checking that the passed value is an Ash.Resource.

Further improvements?

Could this be improved to test it being an AshAuthentication.TokenResource directly?

[zachdaniel]

I would suggest doing Spark.Dsl.is?(Ash.Resource) :)

[simpers]

That's exactly what I was looking for! Haha thanks