Difference between add_dependency and add_runtime_dependency?

Question

What is the difference between using add_dependency and add_runtime_dependency in a Rails engine's gemspec?

For example:

Gem::Specification.new do |s|
  s.add_dependency 'jquery-rails'
  s.add_runtime_dependency 'jquery-rails'
end

What's the difference between them?

Answer 1

They are the same. add_dependency is just an alias for add_runtime_dependency.