class RuboCop::Cop::Style::RegexpLiteral

Enforces using ‘//` or `%r` around regular expressions.

NOTE: The following ‘%r` cases using a regexp starts with a blank or `=` as a method argument allowed to prevent syntax errors.

source,ruby

do_something %r{ regexp} # ‘do_something / regexp/` is an invalid syntax. do_something %r{=regexp} # `do_something /=regexp/` is an invalid syntax.


@example EnforcedStyle: slashes (default)

# bad
snake_case = %r{^[\dA-Z_]+$}

# bad
regex = %r{
  foo
  (bar)
  (baz)
}x

# good
snake_case = /^[\dA-Z_]+$/

# good
regex = /
  foo
  (bar)
  (baz)
/x

@example EnforcedStyle: percent_r

# bad
snake_case = /^[\dA-Z_]+$/

# bad
regex = /
  foo
  (bar)
  (baz)
/x

# good
snake_case = %r{^[\dA-Z_]+$}

# good
regex = %r{
  foo
  (bar)
  (baz)
}x

@example EnforcedStyle: mixed

# bad
snake_case = %r{^[\dA-Z_]+$}

# bad
regex = /
  foo
  (bar)
  (baz)
/x

# good
snake_case = /^[\dA-Z_]+$/

# good
regex = %r{
  foo
  (bar)
  (baz)
}x

@example AllowInnerSlashes: false (default)

# If `false`, the cop will always recommend using `%r` if one or more
# slashes are found in the regexp string.

# bad
x =~ /home\//

# good
x =~ %r{home/}

@example AllowInnerSlashes: true

# good
x =~ /home\//

Constants

MSG_USE_PERCENT_R
MSG_USE_SLASHES

Public Instance Methods

on_regexp(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 101
def on_regexp(node)
  message = if slash_literal?(node)
              MSG_USE_PERCENT_R unless allowed_slash_literal?(node)
            else
              MSG_USE_SLASHES unless allowed_percent_r_literal?(node)
            end

  return unless message

  add_offense(node, message: message) do |corrector|
    correct_delimiters(node, corrector)
    correct_inner_slashes(node, corrector)
  end
end

Private Instance Methods

allow_inner_slashes?() click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 144
def allow_inner_slashes?
  cop_config['AllowInnerSlashes']
end
allowed_mixed_percent_r?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 132
def allowed_mixed_percent_r?(node)
  (style == :mixed && node.multiline?) || contains_disallowed_slash?(node)
end
allowed_mixed_slash?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 122
def allowed_mixed_slash?(node)
  style == :mixed && node.single_line? && !contains_disallowed_slash?(node)
end
allowed_omit_parentheses_with_percent_r_literal?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 161
def allowed_omit_parentheses_with_percent_r_literal?(node)
  return false unless node.parent&.call_type?
  return true if node.content.start_with?(' ', '=')

  enforced_style = config.for_cop('Style/MethodCallWithArgsParentheses')['EnforcedStyle']

  enforced_style == 'omit_parentheses'
end
allowed_percent_r_literal?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 126
def allowed_percent_r_literal?(node)
  (style == :slashes && contains_disallowed_slash?(node)) ||
    style == :percent_r ||
    allowed_mixed_percent_r?(node) || allowed_omit_parentheses_with_percent_r_literal?(node)
end
allowed_slash_literal?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 118
def allowed_slash_literal?(node)
  (style == :slashes && !contains_disallowed_slash?(node)) || allowed_mixed_slash?(node)
end
calculate_replacement(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 221
def calculate_replacement(node)
  if slash_literal?(node)
    ['%r', ''].zip(preferred_delimiters).map(&:join)
  else
    %w[/ /]
  end
end
contains_disallowed_slash?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 136
def contains_disallowed_slash?(node)
  !allow_inner_slashes? && contains_slash?(node)
end
contains_slash?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 140
def contains_slash?(node)
  node_body(node).include?('/')
end
correct_delimiters(node, corrector) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 170
def correct_delimiters(node, corrector)
  replacement = calculate_replacement(node)
  corrector.replace(node.loc.begin, replacement.first)
  corrector.replace(node.loc.end, replacement.last)
end
correct_inner_slashes(node, corrector) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 176
def correct_inner_slashes(node, corrector)
  regexp_begin = node.loc.begin.end_pos

  inner_slash_indices(node).each do |index|
    start = regexp_begin + index

    corrector.replace(
      range_between(
        start,
        start + inner_slash_before_correction(node).length
      ),
      inner_slash_after_correction(node)
    )
  end
end
inner_slash_after_correction(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 209
def inner_slash_after_correction(node)
  inner_slash_for(calculate_replacement(node).first)
end
inner_slash_before_correction(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 205
def inner_slash_before_correction(node)
  inner_slash_for(node.loc.begin.source)
end
inner_slash_for(opening_delimiter) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 213
def inner_slash_for(opening_delimiter)
  if ['/', '%r/'].include?(opening_delimiter)
    '\/'
  else
    '/'
  end
end
inner_slash_indices(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 192
def inner_slash_indices(node)
  text    = node_body(node, include_begin_nodes: true)
  pattern = inner_slash_before_correction(node)
  index   = -1
  indices = []

  while (index = text.index(pattern, index + 1))
    indices << index
  end

  indices
end
node_body(node, include_begin_nodes: false) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 148
def node_body(node, include_begin_nodes: false)
  types = include_begin_nodes ? %i[str begin] : %i[str]
  node.each_child_node(*types).map(&:source).join
end
preferred_delimiters() click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 157
def preferred_delimiters
  config.for_cop('Style/PercentLiteralDelimiters') ['PreferredDelimiters']['%r'].chars
end
slash_literal?(node) click to toggle source
# File lib/rubocop/cop/style/regexp_literal.rb, line 153
def slash_literal?(node)
  node.loc.begin.source == '/'
end