lib/rubocop/cop/lint/literal_in_interpolation.rb
# frozen_string_literal: true
module RuboCop
module Cop
module Lint
# Checks for interpolated literals.
#
# @example
#
# # bad
#
# "result is #{10}"
#
# @example
#
# # good
#
# "result is 10"
class LiteralInInterpolation < Base
include Interpolation
include RangeHelp
include PercentLiteral
extend AutoCorrector
MSG = 'Literal interpolation detected.'
COMPOSITE = %i[array hash pair irange erange].freeze
def on_interpolation(begin_node)
final_node = begin_node.children.last
return unless offending?(final_node)
# %W and %I split the content into words before expansion
# treating each interpolation as a word component, so
# interpolation should not be removed if the expanded value
# contains a space character.
expanded_value = autocorrected_value(final_node)
return if in_array_percent_literal?(begin_node) && /\s|\A\z/.match?(expanded_value)
add_offense(final_node) do |corrector|
return if final_node.dstr_type? # nested, fixed in next iteration
corrector.replace(final_node.parent, expanded_value)
end
end
private
def offending?(node)
node &&
!special_keyword?(node) &&
prints_as_self?(node) &&
# Special case for Layout/TrailingWhitespace
!(space_literal?(node) && ends_heredoc_line?(node))
end
def special_keyword?(node)
# handle strings like __FILE__
(node.str_type? && !node.loc.respond_to?(:begin)) || node.source_range.is?('__LINE__')
end
# rubocop:disable Metrics/MethodLength, Metrics/CyclomaticComplexity
def autocorrected_value(node)
case node.type
when :int
node.children.last.to_i.to_s
when :float
node.children.last.to_f.to_s
when :str
autocorrected_value_for_string(node)
when :sym
autocorrected_value_for_symbol(node)
when :array
autocorrected_value_for_array(node)
when :hash
autocorrected_value_for_hash(node)
when :nil
''
else
node.source.gsub('"', '\"')
end
end
# rubocop:enable Metrics/MethodLength, Metrics/CyclomaticComplexity
def autocorrected_value_for_string(node)
if node.source.start_with?("'", '%q')
node.children.last.inspect[1..-2]
else
node.children.last
end
end
def autocorrected_value_for_symbol(node)
end_pos =
node.loc.end ? node.loc.end.begin_pos : node.source_range.end_pos
range_between(node.loc.begin.end_pos, end_pos).source.gsub('"', '\"')
end
def autocorrected_value_in_hash_for_symbol(node)
# TODO: We need to detect symbol unacceptable names more correctly
if / |"|'/.match?(node.value.to_s)
":\\\"#{node.value.to_s.gsub('"') { '\\\\\"' }}\\\""
else
":#{node.value}"
end
end
def autocorrected_value_for_array(node)
return node.source.gsub('"', '\"') unless node.percent_literal?
contents_range(node).source.split.to_s.gsub('"', '\"')
end
def autocorrected_value_for_hash(node)
hash_string = node.children.map do |child|
key = autocorrected_value_in_hash(child.key)
value = autocorrected_value_in_hash(child.value)
"#{key}=>#{value}"
end.join(', ')
"{#{hash_string}}"
end
# rubocop:disable Metrics/MethodLength, Metrics/AbcSize
def autocorrected_value_in_hash(node)
case node.type
when :int
node.children.last.to_i.to_s
when :float
node.children.last.to_f.to_s
when :str
"\\\"#{node.value.to_s.gsub('"') { '\\\\\"' }}\\\""
when :sym
autocorrected_value_in_hash_for_symbol(node)
when :array
autocorrected_value_for_array(node)
when :hash
autocorrected_value_for_hash(node)
else
node.source.gsub('"', '\"')
end
end
# rubocop:enable Metrics/MethodLength, Metrics/AbcSize
# Does node print its own source when converted to a string?
def prints_as_self?(node)
node.basic_literal? ||
(COMPOSITE.include?(node.type) && node.children.all? { |child| prints_as_self?(child) })
end
def space_literal?(node)
node.str_type? && node.value.blank?
end
def ends_heredoc_line?(node)
grandparent = node.parent.parent
return false unless grandparent&.dstr_type? && grandparent&.heredoc?
line = processed_source.lines[node.last_line - 1]
line.size == node.loc.last_column + 1
end
def in_array_percent_literal?(node)
parent = node.parent
return false unless parent.dstr_type? || parent.dsym_type?
grandparent = parent.parent
grandparent&.array_type? && grandparent&.percent_literal?
end
end
end
end
end