Do not generate unused components contents in `app:update` task

Currently, `app:update` generates all contents regardless of the
component using in application.

For example, even if not using Action Cable, `app:update` will generate
a contents related to Action Cable. This is a little inconvenient.
This PR checks the existence of the component and does not generate
unnecessary contents.
Can not check all options in this way. However, it will be able to
prevent the generation of unnecessary files.

1 files changed, 16 insertions, 0 deletions

diff --git a/railties/test/generators/app_generator_test.rb b/railties/test/generators/app_generator_test.rb
index 059c2692be..ffdee3a6b5 100644
--- a/railties/test/generators/app_generator_test.rb
+++ b/railties/test/generators/app_generator_test.rb
@@ -278,6 +278,22 @@ class AppGeneratorTest < Rails::Generators::TestCase
     end
   end
 
+  def test_app_update_does_not_generate_action_cable_contents_when_skip_action_cable_is_given
+    app_root = File.join(destination_root, "myapp")
+    run_generator [app_root, "--skip-action-cable"]
+
+    FileUtils.cd(app_root) do
+      # For avoid conflict file
+      FileUtils.rm("#{app_root}/config/secrets.yml")
+      quietly { system("bin/rails app:update") }
+    end
+
+    assert_no_file "#{app_root}/config/cable.yml"
+    assert_file "#{app_root}/config/environments/production.rb" do |content|
+      assert_no_match(/config\.action_cable/, content)
+    end
+  end
+
   def test_application_names_are_not_singularized
     run_generator [File.join(destination_root, "hats")]
     assert_file "hats/config/environment.rb", /Rails\.application\.initialize!/