Splat arguments can be helpful, and it turns out we don’t need to forsake them when we’re building Rake tasks, either.

Let’s say we want to build an elasticsearch:reindex task that allows an optional list of entity types to reindex:

namespace :elasticsearch do
  task :reindex do |_t, args|
    Search::Container["search.operations.enqueue_reindex"].(*args.extras)
  end
end

Rake gives us a TaskArguments#extras method, which returns the values not associated with any of the task’s named arguments.

So now we can call our rake task like so:

rake elasticsearch:reindex[products, posts]

And args.extras gives us this:

["products", "posts"]