module Roadie::Rails::Utils

Public Instance Methods

combine_callable(first, second) click to toggle source

Return a callable that will call both inputs. If either is nil, then just return the other.

The result from the second one will be the result of the combined callable.

“‘ruby combine_callable(-> { 1 }, -> { 2 }).call # => 2 combine_callable(-> { 1 }, nil).call # => 1 combine_callable(nil, nil).nil? # => true “`

# File lib/roadie/rails/utils.rb, line 27
def combine_callable(first, second)
  combine_nilable(first, second) do |a, b|
    lambda do |*args|
      a.call(*args)
      b.call(*args)
    end
  end
end
combine_hash(first, second) click to toggle source

Combine two hashes, or return the non-nil hash if either is nil. Returns nil if both are nil.

# File lib/roadie/rails/utils.rb, line 10
def combine_hash(first, second)
  combine_nilable(first, second) do |a, b|
    a.merge(b)
  end
end
combine_nilable(first, second) { |first, second| ... } click to toggle source

Discard the nil value. If neither is nil, then yield both and return the result from the block.

“‘ruby combine_nilable(nil, 5) { |a, b| a+b } # => 5 combine_nilable(7, nil) { |a, b| a+b } # => 7 combine_nilable(nil, nil) { |a, b| a+b } # => nil combine_nilable(7, 5) { |a, b| a+b } # => 12 “`

# File lib/roadie/rails/utils.rb, line 53
def combine_nilable(first, second)
  if first && second
    yield first, second
  else
    first || second
  end
end
combine_providers(first, second) click to toggle source

Combine two Provider ducks into a ProviderList. If either is nil, pick the non-nil value instead.

# File lib/roadie/rails/utils.rb, line 38
def combine_providers(first, second)
  combine_nilable(first, second) do |a, b|
    ProviderList.new(a.to_a + Array.wrap(b))
  end
end