Unset Array type resolves to nil

[bessey]

What did you do?

Given this config:

class AppConfig < Anyway::Config
  attr_config(
    :extra_valid_hosts,
  )

  coerce_types(
    extra_valid_hosts:  { type: :string, array: true },
  )
end

And nothing setting the value of APP_EXTRA_VALID_HOSTS...

What did you expect to happen?

I expect AppConfig.new.extra_valid_hosts to return [] because I have explicitly told AnywayConfig that its an array type.

[3] pry(main)> ENV["APP_EXTRA_VALID_HOSTS"] = ","
=> ","
[6] pry(main)> AppConfig.new.extra_valid_hosts
=> []
[7] pry(main)> ENV["APP_EXTRA_VALID_HOSTS"] = nil
=> nil
[9] pry(main)> AppConfig.new.extra_valid_hosts
=> [] # <<<<<<<< Good

What actually happened?

It returns nil

[3] pry(main)> ENV["APP_EXTRA_VALID_HOSTS"] = ","
=> ","
[6] pry(main)> AppConfig.new.extra_valid_hosts
=> []
[7] pry(main)> ENV["APP_EXTRA_VALID_HOSTS"] = nil
=> nil
[9] pry(main)> AppConfig.new.extra_valid_hosts
=> nil # <<<<<<<< Bad

Environment

Ruby Version: 3.1

Framework Version (Rails, whatever): Rails 6.1

Anyway Config Version: 2.3.1

[palkan]

I expect AppConfig.new.extra_valid_hosts to return [] because I have explicitly told AnywayConfig that its an array type.

I think, nil is expected here, since it's the absence of the value, not an empty one. It can have a different meaning (e.g., if you want to implement a custom fallback option). And we coerce provided values; if nothing is provided, we cannot do anything.

In your cases, providing a default value should work as expected:

class AppConfig < Anyway::Config
  attr_config(
    extra_valid_hosts: []
  )
end