MONGOID-5042 rails g mongoid:config is not working on Rails 6.1

[awesome]

# lib/rails/generators/mongoid/config/config_generator.rb
module Mongoid
  module Generators
    class ConfigGenerator < Rails::Generators::Base

      def app_name
        #
        # 1A)
        # https://api.rubyonrails.org/classes/Rails/Generators/NamedBase.html#method-i-application_name
        #require 'rails/generators/actions'
        #require 'rails/generators/named_base'
        #Rails::Generators::NamedBase.new([""]).send(:application_name)
        #
        # --OR--
        #
        # 1B)
        #Rails.application.class.name.split("::").first.underscore
        # 
        # 2)
        # https://api.rubyonrails.org/classes/Module.html#method-i-module_parent_name
        Rails.application.class.module_parent_name.underscore
      end

Ticket: https://jira.mongodb.org/browse/MONGOID-5042

Alternative PR: #4941

[awesome]

@p-mongo do you know about this git error cloning the submodule for testing? The submodule test-apps works, but https://github.com/mongodb-labs/mongo-ruby-spec-shared does not. Maybe a GitHub permissions setting on spec-shared?

$ git clone --recurse-submodules https://github.com/mongodb/mongoid.git mongoid_upstream
[...]
Failed to clone 'spec/shared' a second time, aborting

@p-mongo ok, figured it out and fixed #4954 . Submodules were using both ssh and https. I'm lazy on a new laptop without ssh key pasted into GitHub account--only using oauth key via desktop client… Submitted PR with all submodules using https so this issue doesn't happen to future lazy contributors.

[awesome]

@p-mongo Hi there! I added tests to app_spec.rb for ~> Rails 6.1 and WFM. See attached: terminal output for running specific test $ APP_TESTS=1 rspec spec/integration/app_spec.rb:90. Please feel free to update PR as you see fit or LMK changes you want. Thanks!

Terminal Saved Output6-success.txt

[midnight-wonderer]

Hi @awesome,
I just send you a patch to preserve the functionality for the old versions of Rails.
awesome#1

I guessed their automated test would break otherwise.

[p-mongo]

This was merged as #4960, thank you.