Rails 6 compatibility

[philippks]

Unfortunately, we had this old gem in a application, which we upgraded from 5.2 to 6.0.

Due to the same issue described in rspec/rspec-rails#2086 we monkey patched coffee-views to make it work again. Feel free to implement it, if you need it.

# Monkey patch for rails 6.
# The fix was adopted from the fix by rspec.
# https://github.com/rspec/rspec-rails/issues/2086
# https://github.com/rails/rails/commit/28f88e0074f473f58c2d3fd54cb3daff81027c12#diff-562906215bf781788ec5aaf37e958cb8
# https://github.com/yury/coffee-views/blob/master/lib/coffee_views/rails.rb#L29
CoffeeViews::Rails::TemplateHandler.class_eval do
  def self.call(template)
    source = compile_coffee(template.source)
    template.instance_variable_set :@source, source

    erb_handler.call(template, _source = source)
  end
end