Add annotations for the alba gem

[mokevnin]

Type of Change

• Add RBI for a new gem

Changes

• Gem name: alba
• Gem version: 4.0.0
• Gem source: https://github.com/okuramasafumi/alba/blob/main/lib/alba/resource.rb
• Gem API doc: https://rubydoc.info/gems/alba/Alba/Resource/ClassMethods
• Tapioca version: 0.19.1
• Sorbet version: 0.6.13164

Alba ships no signatures, so tapioca emits every Alba::Resource::ClassMethods DSL macro sig-less. This adds signatures for the class-level macros used to define a resource. Every parameter list matches the one tapioca generates; every type is taken from the method body and its YARD doc.

• attribute / attributes — name is String/Symbol, if: is Symbol or Proc (Alba::ConditionalAttribute#condition_passes? branches on exactly those two), extra keywords are the untyped name => type pairs handed to Alba::TypedAttribute.
• association and its aliases one, many, has_one, has_many — types taken from the YARD @param tags on association, which the aliases share; resource:/serializer: accept a resource class, a String, or a Proc.
• nested_attribute / nested, trait — block is class_eval'd, so it is bound to an untyped self and returns nothing useful.
• on_error — handler is one of :raise, :ignore, :nullify; the block is called as on_error.call(error, obj, key, attribute, klass) and its [key, value] return is destructured, hence T::Array[T.untyped].
• on_nil — called as instance_exec(obj, key, attribute, &nil_handler).
• meta, layout, helper, collection_key, root_key, root_key!, root_key_for_collection, transform_keys, prefer_object_method!, prefer_resource_method! — direct reads of the assignments in each body.

Two notes:

• The block on attribute (and on trait and nested_attribute) is declared non-nilable. It is syntactically optional, but all three raise ArgumentError immediately when it is absent, so a call without a block can only ever fail at runtime.
• transform_keys! is left unannotated: it returns the anonymous dup of the resource class, is marked experimental in the source, and I could not type it honestly.

Instance methods (serialize, as_json, serializable_hash) are deliberately left out of this first pass — serializable_hash returns a Hash or an Array depending on whether the object is a collection, and a union return there would tighten code that type-checks today.

bundle exec repo check --gem --ref upstream/main passes locally on all five checks (index, rubocop, rubygems, runtime, static).

[KaanOzkan]

Suggested change

	block: T.nilable(T.proc.params(error: T.untyped, object: T.untyped, key: T.untyped, attribute: T.untyped, resource_class: T.untyped).returns(T::Array[T.untyped])),
	block: T.nilable(T.proc.params(error: T.untyped, object: T.untyped, key: T.untyped, attribute: T.untyped, resource_class: T.untyped).returns(T.untyped)),

Looks like it can return any constant? https://github.com/okuramasafumi/alba/blob/v4.0.0/test/usecases/on_error_test.rb#L60-L63

[mokevnin]

Good catch — the return goes straight back to the caller, so T::Array[T.untyped] was wrong. Applied in d63f627.

[KaanOzkan]

This seems better

Suggested change

	resource: T.nilable(T.any(Module, String, Proc)),
	serializer: T.nilable(T.any(Module, String, Proc)),
	resource: T.nilable(T.any(T::Class[Alba::Resource], String, Proc)),
	serializer: T.nilable(T.any(T::Class[Alba::Resource], String, Proc)),

https://github.com/okuramasafumi/alba/blob/fd805a70f8bedbfd1cfc50eb589afa553469ace4/lib/alba/resource.rb#L392-L393

[KaanOzkan]

Similarly for one, has_many, has_one, many

[mokevnin]

Agreed, T::Class[Alba::Resource] is the honest type. Applied in d63f627.

[mokevnin]

Done — association, one, many, has_one and has_many all carry the same signature now. bundle exec repo check --gem alba is green.