Add support for Kaminari

Gemfile

@@ -11,6 +11,7 @@ group :development do
   gem "minitest-reporters"
 
   gem "attr_json"
+  gem "kaminari-activerecord"
   gem "money-rails"
   gem "paperclip"
   gem "rails", "~> 7.2"

Gemfile.lock

@@ -101,6 +101,10 @@ GEM
       rdoc (>= 4.0.0)
       reline (>= 0.4.2)
     json (2.7.2)
+    kaminari-activerecord (1.2.2)
+      activerecord
+      kaminari-core (= 1.2.2)
+    kaminari-core (1.2.2)
     language_server-protocol (3.17.0.3)
     logger (1.6.1)
     loofah (2.22.0)
@@ -289,6 +293,7 @@ PLATFORMS
 DEPENDENCIES
   attr_json
   boba!
+  kaminari-activerecord
   minitest
   minitest-hooks
   minitest-reporters

lib/tapioca/dsl/compilers/kaminari.rb

@@ -0,0 +1,85 @@
+# typed: strict
+# frozen_string_literal: true
+
+return unless defined?(Kaminari)
+
+require "tapioca/dsl/helpers/active_record_constants_helper"
+
+module Tapioca
+  module Dsl
+    module Compilers
+      # `Tapioca::Dsl::Compilers::Kaminari` decorates RBI files for models
+      # using Kaminari.
+      #
+      # For example, with Kaminari installed and the following `ActiveRecord::Base` subclass:
+      #
+      # ~~~rb
+      # class Post < ApplicationRecord
+      # end
+      # ~~~
+      #
+      # This compiler will produce the RBI file `post.rbi` with the following content:
+      #
+      # ~~~rbi
+      # # post.rbi
+      # # typed: true
+      # class Post
+      #   extend GeneratedRelationMethods
+      #
+      #   module GeneratedRelationMethods
+      #     sig do
+      #       params(
+      #         num: T.any(Integer, String)
+      #       ).returns(T.all(PrivateRelation, Kaminari::PageScopeMethods, Kaminari::ActiveRecordRelationMethods))
+      #     end
+      #     def page(num = nil); end
+      #   end
+      # end
+      # ~~~
+      class Kaminari < Tapioca::Dsl::Compiler
+        extend T::Sig
+        include Helpers::ActiveRecordConstantsHelper
+
+        ConstantType = type_member { { fixed: T.class_of(::ActiveRecord::Base) } }
+
+        sig { override.void }
+        def decorate
+          root.create_path(constant) do |model|
+            target_modules.each do |module_name, return_type|
+              model.create_module(module_name).create_method(
+                ::Kaminari.config.page_method_name.to_s,
+                parameters: [create_opt_param("num", type: "T.any(Integer, String)", default: "nil")],
+                return_type: "T.all(#{return_type}, Kaminari::PageScopeMethods, Kaminari::ActiveRecordRelationMethods)",
+              )
+            end
+
+            model.create_extend(RelationMethodsModuleName)
+          end
+        end
+
+        class << self
+          extend T::Sig
+
+          sig { override.returns(T::Enumerable[Module]) }
+          def gather_constants
+            descendants_of(::ActiveRecord::Base).reject(&:abstract_class?)
+          end
+        end
+
+        private
+
+        sig { returns(T::Array[[String, String]]) }
+        def target_modules
+          if compiler_enabled?("ActiveRecordRelations")
+            [
+              [RelationMethodsModuleName, RelationClassName],
+              [AssociationRelationMethodsModuleName, AssociationRelationClassName],
+            ]
+          else
+            [[RelationMethodsModuleName, "T.untyped"]]
+          end
+        end
+      end
+    end
+  end
+end

manual/compiler_kaminari.md

@@ -0,0 +1,30 @@
+## Kaminari
+
+`Tapioca::Dsl::Compilers::Kaminari` decorates RBI files for models
+using Kaminari.
+
+For example, with Kaminari installed and the following `ActiveRecord::Base` subclass:
+
+~~~rb
+class Post < ApplicationRecord
+end
+~~~
+
+This compiler will produce the RBI file `post.rbi` with the following content:
+
+~~~rbi
+# post.rbi
+# typed: true
+class Post
+  extend GeneratedRelationMethods
+
+  module GeneratedRelationMethods
+    sig do
+      params(
+        num: T.any(Integer, String)
+      ).returns(T.all(PrivateRelation, Kaminari::PageScopeMethods, Kaminari::ActiveRecordRelationMethods))
+    end
+    def page(num = nil); end
+  end
+end
+~~~

manual/compilers.md

@@ -8,6 +8,7 @@ This list is an evergeen list of currently available compilers.
 * [ActiveRecordAssociationsPersisted](compiler_activerecordassociationspersisted.md)
 * [ActiveRecordColumnsPersisted](compiler_activerecordcolumnspersisted.md)
 * [AttrJson](compiler_attrjson.md)
+* [Kaminari](compiler_kaminari.md)
 * [MoneyRails](compiler_moneyrails.md)
 * [Paperclip](compiler_paperclip.md)
 <!-- END_COMPILER_LIST -->