Freshly/spicerack

# frozen_string_literal: true

# RSpec matcher that tests usages of [Module#alias_method](https://apidock.com/ruby/Module/alias_method)
#
#     class Klass
#       def old_name; end
#       alias_method :alias_name, :old_name
#     end
#
#     RSpec.describe Klass do
#       it { is_expected.to alias_method :alias_name, :old_name }
#     end

RSpec::Matchers.define :alias_method do |alias_name, target_name|
  match do |instance|
    instance.method(alias_name) == instance.method(target_name)
  end

  description do
    "aliases #{target_name} as #{alias_name}"
  end

  failure_message do |instance|
    "expected #{instance.class.name}##{alias_name} to be an alias of #{target_name}"
  end

  failure_message_when_negated do |instance|
    "expected #{instance.class.name}##{alias_name} to not be an alias of #{target_name}"
  end
end