Rails application type generator

lib/sorbet-rails/application_rbi_formatter.rb

@@ -0,0 +1,25 @@
+# typed: true
+class ApplicationRbiFormatter
+  def initialize(rails_application_class_name)
+    @rails_application_class_name = rails_application_class_name
+  end
+
+  def generate_rbi
+    puts "-- Generate sigs for Rails::Application --"
+
+    <<~"RBI"
+      # This is an autogenerated file for your Rails::Application subclass
+
+      # typed: strong
+      class #{@rails_application_class_name} < Rails::Application
+      end
+
+      module Rails
+        extend T::Sig
+
+        sig { returns(#{@rails_application_class_name}) }
+        def self.application; end
+      end
+    RBI
+  end
+end

lib/sorbet-rails/tasks/rails_rbi.rake

@@ -1,3 +1,4 @@
+require("sorbet-rails/application_rbi_formatter")
 require("sorbet-rails/model_rbi_formatter")
 require("sorbet-rails/routes_rbi_formatter")
 require("sorbet-rails/helper_rbi_formatter")
@@ -9,6 +10,15 @@ require("sorbet-rails/utils")
 
 namespace :rails_rbi do
 
+  desc "Generate rbis for rails application"
+  task application: :environment do |t, args|
+    rails_application_class_name = Rails.application.class.name
+    formatter = ApplicationRbiFormatter.new(rails_application_class_name)
+    file_path = Rails.root.join("sorbet", "rails-rbi", "application.rbi")
+    FileUtils.mkdir_p(File.dirname(file_path))
+    File.write(file_path, formatter.generate_rbi)
+  end
+
   desc "Generate rbis for rails routes"
   task :routes, [:root_dir] => :environment do |t, args|
     all_routes = Rails.application.routes.routes

spec/application_rbi_formatter_spec.rb

@@ -0,0 +1,12 @@
+require 'rails_helper'
+require 'sorbet-rails/application_rbi_formatter'
+
+RSpec.describe ApplicationRbiFormatter do
+  it 'returns the expected rbi for an application' do
+    formatter = ApplicationRbiFormatter.new(Rails.application.class.name)
+    expect_match_file(
+      formatter.generate_rbi,
+      'expected_application.rbi'
+    )
+  end
+end

spec/rake_rails_rbi_application_spec.rb

@@ -0,0 +1,15 @@
+require 'rails_helper'
+
+RSpec.describe 'rake rails_rbi:application', type: :task do
+
+  it "preloads the Rails environment" do
+    expect(task.prerequisites).to include("environment")
+  end
+
+  it "generates application.rbi correctly" do
+    task.invoke
+    expected_path = Rails.root.join("sorbet", "rails-rbi", "application.rbi")
+    generated = File.read(expected_path)
+    expect_match_file(generated, 'expected_application.rbi')
+  end
+end

spec/support/v4.2/config/application.rb

@@ -16,7 +16,7 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module V42
+module Hogwarts_4_2
   class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers

spec/support/v5.0/config/application.rb

@@ -17,7 +17,7 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module V50
+module Hogwarts_5_0
   class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.
     # Application configuration should go into files in config/initializers

spec/support/v5.1/config/application.rb

@@ -17,7 +17,7 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module RailsApp517
+module Hogwarts_5_17
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 5.1

spec/support/v5.2-no-sorbet/config/application.rb

@@ -18,7 +18,7 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module RailsApp
+module Hogwarts_5_2_NoSorbet
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 5.2

spec/support/v5.2/config/application.rb

@@ -18,7 +18,7 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module RailsApp
+module Hogwarts_5_2
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 5.2

spec/support/v6.0/config/application.rb

@@ -20,7 +20,7 @@
 # you've limited to :test, :development, or :production.
 Bundler.require(*Rails.groups)
 
-module V60
+module Hogwarts_6_0
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 6.0

spec/test_data/v4.2/expected_application.rbi

@@ -0,0 +1,12 @@
+# This is an autogenerated file for your Rails::Application subclass
+
+# typed: strong
+class Hogwarts_4_2::Application < Rails::Application
+end
+
+module Rails
+  extend T::Sig
+
+  sig { returns(Hogwarts_4_2::Application) }
+  def self.application; end
+end

spec/test_data/v5.0/expected_application.rbi

@@ -0,0 +1,12 @@
+# This is an autogenerated file for your Rails::Application subclass
+
+# typed: strong
+class Hogwarts_5_0::Application < Rails::Application
+end
+
+module Rails
+  extend T::Sig
+
+  sig { returns(Hogwarts_5_0::Application) }
+  def self.application; end
+end

spec/test_data/v5.1/expected_application.rbi

@@ -0,0 +1,12 @@
+# This is an autogenerated file for your Rails::Application subclass
+
+# typed: strong
+class Hogwarts_5_17::Application < Rails::Application
+end
+
+module Rails
+  extend T::Sig
+
+  sig { returns(Hogwarts_5_17::Application) }
+  def self.application; end
+end

spec/test_data/v5.2-no-sorbet/expected_application.rbi

@@ -0,0 +1,12 @@
+# This is an autogenerated file for your Rails::Application subclass
+
+# typed: strong
+class Hogwarts_5_2_NoSorbet::Application < Rails::Application
+end
+
+module Rails
+  extend T::Sig
+
+  sig { returns(Hogwarts_5_2_NoSorbet::Application) }
+  def self.application; end
+end

spec/test_data/v5.2/expected_application.rbi

@@ -0,0 +1,12 @@
+# This is an autogenerated file for your Rails::Application subclass
+
+# typed: strong
+class Hogwarts_5_2::Application < Rails::Application
+end
+
+module Rails
+  extend T::Sig
+
+  sig { returns(Hogwarts_5_2::Application) }
+  def self.application; end
+end

spec/test_data/v6.0/expected_application.rbi

@@ -0,0 +1,12 @@
+# This is an autogenerated file for your Rails::Application subclass
+
+# typed: strong
+class Hogwarts_6_0::Application < Rails::Application
+end
+
+module Rails
+  extend T::Sig
+
+  sig { returns(Hogwarts_6_0::Application) }
+  def self.application; end
+end