Question

Very often in Ruby (and Rails specifically) you have to check if something exists and then perform an action on it, for example:

if @objects.any?
  puts "We have these objects:"
  @objects.each { |o| puts "hello: #{o}"
end

This is as short as it gets and all is good, but what if you have @objects.some_association.something.hit_database.process instead of @objects? I would have to repeat it second time inside the if expression and what if I don’t know the implementation details and the method calls are expensive?

The obvious choice is to create a variable and then test it and then process it, but then you have to come up with a variable name (ugh) and it will also hang around in memory until the end of the scope.

Why not something like this:

@objects.some_association.something.hit_database.process.with :any? do |objects|
    puts "We have these objects:"
    objects.each { ... }
end

How would you do this?

Answer 1

What about tap?

@objects.some_association.something.hit_database.process.tap do |objects|
  if objects.any?
    puts "We have these objects:"
    objects.each { ... }
  end
end