Update zeitwerk:check

Author: fxn

railties/lib/rails/tasks/zeitwerk.rake

@@ -1,19 +1,16 @@
 # frozen_string_literal: true
 
-eager_load = ->() do
-  puts "Hold on, I am eager loading the application."
-  Zeitwerk::Loader.eager_load_all
-end
+require "rails/zeitwerk_checker"
 
-report_not_checked = ->(not_checked) do
+report_unchecked = ->(unchecked) do
   puts
   puts <<~EOS
     WARNING: The following directories will only be checked if you configure
     them to be eager loaded:
   EOS
   puts
 
-  not_checked.each { |dir| puts "  #{dir}" }
+  unchecked.each { |dir| puts "  #{dir}" }
   puts
 
   puts <<~EOS
@@ -23,39 +20,22 @@ report_not_checked = ->(not_checked) do
   puts
 end
 
-report = ->(not_checked) do
-  if not_checked.any?
-    report_not_checked[not_checked]
-    puts "Otherwise, all is good!"
-  else
-    puts "All is good!"
-  end
-end
-
 namespace :zeitwerk do
   desc "Check project structure for Zeitwerk compatibility"
   task check: :environment do
+    puts "Hold on, I am eager loading the application."
+
     begin
-      eager_load[]
-    rescue NameError => e
-      if e.message =~ /expected file .*? to define constant [\w:]+/
-        abort $&.sub(/expected file #{Regexp.escape(Rails.root.to_s)}./, "expected file ")
-      else
-        raise
-      end
+      unchecked = Rails::ZeitwerkChecker.check
+    rescue Zeitwerk::NameError => e
+      abort e.message.sub(/#{Regexp.escape(Rails.root.to_s)}./, "")
     end
 
-    require "active_support/core_ext/object/try"
-    eager_load_paths = Rails.configuration.eager_load_namespaces.filter_map do |eln|
-      # Quick regression fix for 6.0.3 to support namespaces that do not have
-      # eager load paths, like the recently added i18n. I'll rewrite this task.
-      eln.try(:config).try(:eager_load_paths)
-    end.flatten
-
-    not_checked = ActiveSupport::Dependencies.autoload_paths - eager_load_paths
-    not_checked.select! { |dir| Dir.exist?(dir) }
-    not_checked.reject! { |dir| Dir.empty?(dir) }
-
-    report[not_checked]
+    if unchecked.empty?
+      puts "All is good!"
+    else
+      report_unchecked[unchecked]
+      puts "Otherwise, all is good!"
+    end
   end
 end

railties/lib/rails/zeitwerk_checker.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+# The actual (private) implementation of the Rake task zeitwerk:check.
+class Rails::ZeitwerkChecker # :nodoc:
+  def self.check
+    Zeitwerk::Loader.eager_load_all
+
+    autoloaded = ActiveSupport::Dependencies.autoload_paths + ActiveSupport::Dependencies.autoload_once_paths
+    eager_loaded = ActiveSupport::Dependencies._eager_load_paths.to_a
+
+    unchecked = autoloaded - eager_loaded
+    unchecked.select! { |dir| Dir.exist?(dir) && !Dir.empty?(dir)  }
+    unchecked
+  end
+end

railties/test/application/zeitwerk_checker_test.rb

@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require "isolation/abstract_unit"
+require "rails/zeitwerk_checker"
+
+class ZeitwerkCheckerTest < ActiveSupport::TestCase
+  include ActiveSupport::Testing::Isolation
+
+  def setup
+    build_app
+  end
+
+  def boot(env = "development")
+    app(env)
+  end
+
+  test "returns an empty list for a default application" do
+    boot
+
+    assert_empty Rails::ZeitwerkChecker.check
+  end
+
+  test "raises if there is a missing constants in autoload_paths" do
+    app_file "app/models/user.rb", ""
+
+    boot
+
+    e = assert_raises(Zeitwerk::NameError) do
+      Rails::ZeitwerkChecker.check
+    end
+    assert_includes e.message, "expected file #{app_path}/app/models/user.rb to define constant User"
+  end
+
+  test "raises if there is a missing constant in autoload_once_paths" do
+    app_dir "extras"
+    app_file "extras/x.rb", ""
+
+    add_to_config 'config.autoload_once_paths << "#{Rails.root}/extras"'
+    add_to_config 'config.eager_load_paths << "#{Rails.root}/extras"'
+
+    boot
+
+    e = assert_raises(Zeitwerk::NameError) do
+      Rails::ZeitwerkChecker.check
+    end
+    assert_includes e.message, "expected file #{Rails.root}/extras/x.rb to define constant X"
+  end
+
+  test "returns an empty list unchecked directories do not exist" do
+    add_to_config 'config.autoload_paths << "#{Rails.root}/dir1"'
+    add_to_config 'config.autoload_once_paths << "#{Rails.root}/dir2"'
+
+    boot
+
+    assert_empty Rails::ZeitwerkChecker.check
+  end
+
+  test "returns an empty list if unchecked directories are empty" do
+    app_dir "dir1"
+    add_to_config 'config.autoload_paths << "#{Rails.root}/dir1"'
+
+    app_dir "dir2"
+    add_to_config 'config.autoload_once_paths << "#{Rails.root}/dir2"'
+
+    boot
+
+    assert_empty Rails::ZeitwerkChecker.check
+  end
+
+  test "returns unchecked directories" do
+    app_dir "dir1"
+    app_file "dir1/x.rb", "X = 1"
+    add_to_config 'config.autoload_paths << "#{Rails.root}/dir1"'
+
+    app_dir "dir2"
+    app_file "dir2/y.rb", "Y = 1"
+    add_to_config 'config.autoload_once_paths << "#{Rails.root}/dir2"'
+
+    boot
+
+    assert_equal ["#{app_path}/dir1", "#{app_path}/dir2"], Rails::ZeitwerkChecker.check.sort
+  end
+end