Add ActiveStorage getter and setter generator for has_one_attached and has_many_attached

lib/tapioca/compilers/dsl/active_storage.rb

@@ -0,0 +1,98 @@
+# typed: strict
+# frozen_string_literal: true
+
+begin
+  require "active_storage"
+  require "active_storage/reflection"
+rescue LoadError
+  return
+end
+
+module Tapioca
+  module Compilers
+    module Dsl
+      # `Tapioca::Compilers::Dsl::ActiveStorage` decorates RBI files for subclasses of
+      # `ActiveRecord::Base` that declare [one](https://edgeguides.rubyonrails.org/active_storage_overview.html#has-one-attached)
+      # or [many](https://edgeguides.rubyonrails.org/active_storage_overview.html#has-many-attached) attachments.
+      #
+      # For example, with the following `ActiveRecord::Base` subclass:
+      #
+      # ~~~rb
+      # class Post < ApplicationRecord
+      #  has_one_attached :photo
+      #  has_many_attached :blogs
+      # end
+      # ~~~
+      #
+      # this generator will produce the RBI file `post.rbi` with the following content:
+      #
+      # ~~~rbi
+      # # typed: strong
+      #
+      # class Post
+      #   sig { returns(ActiveStorage::Attached::Many) }
+      #   def blogs; end
+      #
+      #   sig { params(attachable: T.untyped).returns(T.untyped) }
+      #   def blogs=(attachable); end
+      #
+      #   sig { returns(ActiveStorage::Attached::One) }
+      #   def photo; end
+      #
+      #   sig { params(attachable: T.untyped).returns(T.untyped) }
+      #   def photo=(attachable); end
+      # end
+      # ~~~
+      class ActiveStorage < Base
+        extend T::Sig
+
+        sig do
+          override.params(root: RBI::Tree,
+            constant: T.all(Module, ::ActiveStorage::Reflection::ActiveRecordExtensions::ClassMethods)).void
+        end
+        def decorate(root, constant)
+          return if constant.reflect_on_all_attachments.empty?
+
+          root.create_path(constant) do |scope|
+            constant.reflect_on_all_attachments.each do |reflection|
+              type = type_of(reflection)
+              name = reflection.name.to_s
+              scope.create_method(
+                name,
+                return_type: type
+              )
+              scope.create_method(
+                "#{name}=",
+                parameters: [create_param("attachable", type: "T.untyped")],
+                return_type: "T.untyped"
+              )
+            end
+          end
+        end
+
+        sig { override.returns(T::Enumerable[Module]) }
+        def gather_constants
+          ActiveRecord::Base.descendants
+            .reject(&:abstract_class?)
+            .grep(::ActiveStorage::Reflection::ActiveRecordExtensions::ClassMethods)
+        end
+
+        private
+
+        sig do
+          params(reflection: ActiveRecord::Reflection::MacroReflection).returns(String)
+        end
+        def type_of(reflection)
+          case reflection
+          when ::ActiveStorage::Reflection::HasOneAttachedReflection
+            "ActiveStorage::Attached::One"
+          when ::ActiveStorage::Reflection::HasManyAttachedReflection
+            "ActiveStorage::Attached::Many"
+          else
+            "T.untyped"
+          end
+        end
+      end
+    end
+  end
+end

manual/generator_activestorage.md

@@ -0,0 +1,34 @@
+## ActiveStorage
+
+`Tapioca::Compilers::Dsl::ActiveStorage` decorates RBI files for subclasses of
+`ActiveRecord::Base` that declare [one](https://edgeguides.rubyonrails.org/active_storage_overview.html#has-one-attached)
+or [many](https://edgeguides.rubyonrails.org/active_storage_overview.html#has-many-attached) attachments.
+
+For example, with the following `ActiveRecord::Base` subclass:
+
+~~~rb
+class Post < ApplicationRecord
+ has_one_attached :photo
+ has_many_attached :blogs
+end
+~~~
+
+this generator will produce the RBI file `post.rbi` with the following content:
+
+~~~rbi
+# typed: strong
+
+class Post
+  sig { returns(ActiveStorage::Attached::Many) }
+  def blogs; end
+
+  sig { params(attachable: T.untyped).returns(T.untyped) }
+  def blogs=(attachable); end
+
+  sig { returns(ActiveStorage::Attached::One) }
+  def photo; end
+
+  sig { params(attachable: T.untyped).returns(T.untyped) }
+  def photo=(attachable); end
+end
+~~~

manual/generators.md

@@ -12,6 +12,7 @@ In the following section you will find all available DSL generators:
 * [ActiveRecordScope](generator_activerecordscope.md)
 * [ActiveRecordTypedStore](generator_activerecordtypedstore.md)
 * [ActiveResource](generator_activeresource.md)
+* [ActiveStorage](generator_activestorage.md)
 * [ActiveSupportConcern](generator_activesupportconcern.md)
 * [ActiveSupportCurrentAttributes](generator_activesupportcurrentattributes.md)
 * [Config](generator_config.md)