brew/Library/Homebrew/rubocops/safe_navigation_with_blank.rb

# typed: true
# frozen_string_literal: true

module RuboCop
  module Cop
    module Homebrew
      # Checks to make sure safe navigation isn't used with `blank?` in
      # a conditional.
      #
      # NOTE: While the safe navigation operator is generally a good idea, when
      #       checking `foo&.blank?` in a conditional, `foo` being `nil` will actually
      #       do the opposite of what the author intends:
      #
      #       ```ruby
      #       foo&.blank? #=> nil
      #       foo.blank? #=> true
      #       ```
      #
      # ### Example
      #
      # ```ruby
      # # bad
      # do_something if foo&.blank?
      # do_something unless foo&.blank?
      #
      # # good
      # do_something if foo.blank?
      # do_something unless foo.blank?
      # ```
      class SafeNavigationWithBlank < Base
        extend AutoCorrector

        MSG = "Avoid calling `blank?` with the safe navigation operator in conditionals."

        def_node_matcher :safe_navigation_blank_in_conditional?, <<~PATTERN
          (if $(csend ... :blank?) ...)
        PATTERN

        def on_if(node)
          return unless safe_navigation_blank_in_conditional?(node)

          add_offense(node) do |corrector|
            corrector.replace(safe_navigation_blank_in_conditional?(node).location.dot, ".")
          end
        end
      end
    end
  end
end