Improve railties generators tests

[bogdanvlviv]

Improve plugin generator tests
Improve app generator tests
Ensure that generation config/application.rb is correct.
Related to #30123

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--skip-action-cable pass throughs rails plugin new (i found this when i was improving tests)

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Also, this PR will prevent making mistakes like: #30101 (comment)
r? @rafaelfranca

[rafaelfranca]

You can squash the first and third commits and the second and the fourth commit

[rafaelfranca]

I prefer the previous name

[bogdanvlviv]

after remove --full option

- test_generating_adds_dummy_app_in_full_mode_without_sprockets
+ test_generating_adds_dummy_app_without_sprockets

[rafaelfranca]

Should we keep the --full option?

[bogdanvlviv]

No, this test hasn't had any relations to --full option, so this is extra here.

[rafaelfranca]

test_default_frameworks_are_required_when_others_are_removed

[rafaelfranca]

We don't need to check this if it is checked in other place.

[bogdanvlviv]

It isn't checked in another place, we need to check it.
A generation of plugin --skip-test has the more complicated case than a generation of app.

If rails plugin new name_plugin --skip-test and --dummy-path is test/dummy(default value the same), it woun't create a dummy app.
(we have condition for creation dummy app: options[:skip_test].blank? || options[:dummy_path] != "test/dummy"),
so it isn't possible to test # require "rails/test_unit/railtie" for existence in config/application.rb,

but we can reach it by rails plugin new name_plugin --skip-test --dummy-path=spec/dummy

[rafaelfranca]

Does this test pass only with the first commit?

[bogdanvlviv]

No, the test fails.
Only
assert_file "test/dummy/config/application.rb", /#\s+require\s+["']action_cable\/engine["']/ passes, it looks strange

[bogdanvlviv]

run_generator [destination_root, "--skip-action-cable"]
assert_file "test/dummy/config/application.rb", /#\s+require\s+["']action_cable\/engine["']/

I think i got why it passes on master,

test/dummy/ is generated by Rails::Generators::AppGenerator with filtered options,

https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/plugin/plugin_generator.rb#L88-L104

then we replace some files in test/dummy/ with all options
https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/plugin/plugin_generator.rb#L106-L112

Next example doesn't pass on master, because these files are generated by Rails::Generators::AppGenerator with filtered options, https://github.com/rails/rails/blob/master/railties/lib/rails/generators/rails/plugin/plugin_generator.rb#L88-L104

run_generator [destination_root, "--skip-action-cable"]
assert_no_file "test/dummy/config/cable.yml"
assert_no_file "test/dummy/app/assets/javascripts/cable.js"
assert_no_directory "test/dummy/app/channels"
assert_file "Gemfile" do |content|
  assert_no_match(/redis/, content)
end

it only will pass if add :skip_action_cable to PASSTHROUGH_OPTIONS. If don't pass :skip_action_cable to PASSTHROUGH_OPTIONS , these files will be always generated because skip_action_cable is false by default https://github.com/rails/rails/blob/master/railties/lib/rails/generators/app_base.rb#L55

[rafaelfranca]

Could you squash this commit with the commit that added the option?

[bogdanvlviv]

Sure

[rafaelfranca]

Really good PR! 👏