Module: RuboCop::Cop::Util

Extended by:
Sexp
Includes:
PathUtil
Included in:
Cop, Lint::UnusedBlockArgument
Defined in:
lib/rubocop/cop/util.rb

Overview

This module contains a collection of useful utility methods.

Constant Summary collapse

BYTE_ORDER_MARK =

The Unicode codepoint

0xfeff
EQUALS_ASGN_NODES = 
[:lvasgn, :ivasgn, :cvasgn, :gvasgn,
:casgn, :masgn].freeze
SHORTHAND_ASGN_NODES = 
[:op_asgn, :or_asgn, :and_asgn].freeze
ASGN_NODES = 
(EQUALS_ASGN_NODES + SHORTHAND_ASGN_NODES).freeze
OPERATOR_METHODS =

phrogz.net/programmingruby/language.html#table_18.4 Backtick is added last just to help editors parse this code.

%w(
  | ^ & <=> == === =~ > >= < <= << >>
  + - * / % ** ~ +@ -@ [] []= ! != !~
).map(&:to_sym).push(:'`').freeze
STRING_ESCAPES = 
{
  '\a' => "\a", '\b' => "\b", '\e' => "\e", '\f' => "\f", '\n' => "\n",
  '\r' => "\r", '\s' => ' ',  '\t' => "\t", '\v' => "\v", "\\\n" => ''
}.freeze
STRING_ESCAPE_REGEX = 
/\\(?:
  [abefnrstv\n]    |   # simple escapes (above)
  \d{1,3}          |   # octal byte escape
  x\d{1,2}         |   # hex byte escape
  u[0-9a-fA-F]{4}  |   # unicode char escape
  u\{[^}]*\}       |   # extended unicode escape
  .                    # any other escaped char
)/x
LITERAL_REGEX =

Match literal regex characters, not including anchors, character classes, alternatives, groups, repetitions, references, etc

/[\w\s\-,"'!#%&<>=;:`~]|\\[^AbBdDgGkwWszZS0-9]/

Class Method Summary collapse

Methods included from Sexp

s

Methods included from PathUtil

absolute?, hidden?, issue_deprecation_warning, match_path?, relative_path

Class Method Details

.begins_its_line?(range) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 175

def begins_its_line?(range)
  (range.source_line =~ /\S/) == range.column
end

.block_length(block_node) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 61

def block_length(block_node)
  block_node.loc.end.line - block_node.loc.begin.line
end

.comment_line?(line_source) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 65

def comment_line?(line_source)
  line_source =~ /^\s*#/
end

.directions(side) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 167

def directions(side)
  if side == :both
    [true, true]
  else
    [side == :left, side == :right]
  end
end

.double_quotes_acceptable?(string) ⇒ Boolean

If double quoted string literals are found in Ruby code, and they are not the preferred style, should they be flagged?

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 230

def double_quotes_acceptable?(string)
  # If a string literal contains hard-to-type characters which would
  # not appear on a "normal" keyboard, then double-quotes are acceptable
  double_quotes_required?(string) ||
    string.codepoints.any? { |cp| cp < 32 || cp > 126 }
end

.double_quotes_required?(string) ⇒ Boolean

If converting a string to Ruby string literal source code, must double quotes be used?

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 218

def double_quotes_required?(string)
  # Double quotes are required for strings which either:
  # - Contain single quotes
  # - Contain non-printable characters, which must use an escape

  # Regex matches IF there is a ' or there is a \\ in the string that is
  # not preceded/followed by another \\ (e.g. "\\x34") but not "\\\\".
  string.inspect =~ /'|(?<! \\) \\{2}* \\ (?![\\"])/x
end

.effective_column(range) ⇒ Object

Returns the column attribute of the range, except if the range is on the first line and there’s a byte order mark at the beginning of that line, in which case 1 is subtracted from the column value. This gives the column as it appears when viewing the file in an editor.



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# File 'lib/rubocop/cop/util.rb', line 123

def effective_column(range)
  if range.line == 1 &&
     @processed_source.raw_source.codepoints.first == BYTE_ORDER_MARK
    range.column - 1
  else
    range.column
  end
end

.ends_its_line?(range) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 179

def ends_its_line?(range)
  line = range.source_buffer.source_line(range.last_line)
  (line =~ /\s*\z/) == range.last_column
end

.first_part_of_call_chain(node) ⇒ Object

Returns, for example, a bare ‘if` node if the given node is an `if` with calls chained to the end of it.



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# File 'lib/rubocop/cop/util.rb', line 192

def first_part_of_call_chain(node)
  while node
    case node.type
    when :send
      receiver, _method_name, _args = *node
      node = receiver
    when :block
      method, _args, _body = *node
      node = method
    else
      break
    end
  end
  node
end

.interpret_string_escapes(string) ⇒ Object

Take a string with embedded escapes, and convert the escapes as the Ruby interpreter would when reading a double-quoted string literal. For example, “\n” will be converted to “n”.



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# File 'lib/rubocop/cop/util.rb', line 256

def interpret_string_escapes(string)
  # We currently don't handle \cx, \C-x, and \M-x
  string.gsub(STRING_ESCAPE_REGEX) do |escape|
    STRING_ESCAPES[escape] || begin
      if escape[1] == 'x'
        [escape[2..-1].hex].pack('C')
      elsif escape[1] == 'u'
        if escape[2] == '{'
          escape[3..-1].split(/\s+/).map(&:hex).pack('U')
        else
          [escape[2..-1].hex].pack('U')
        end
      elsif escape[1] =~ /\d/ # octal escape
        [escape[1..-1].to_i(8)].pack('C')
      else
        escape[1] # literal escaped char, like \\
      end
    end
  end
end

.line_range(arg) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 69

def line_range(arg)
  source_range = case arg
                 when Parser::Source::Range
                   arg
                 when Parser::AST::Node
                   arg.source_range
                 else
                   raise ArgumentError, "Invalid argument #{arg}"
                 end

  source_range.begin.line..source_range.end.line
end

.move_pos(src, pos, step, condition, regexp) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 161

def move_pos(src, pos, step, condition, regexp)
  offset = step == -1 ? -1 : 0
  pos += step while condition && src[pos + offset] =~ regexp
  pos
end

.numeric_range_size(range) ⇒ Object

Range#size is not available prior to Ruby 2.0.



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# File 'lib/rubocop/cop/util.rb', line 209

def numeric_range_size(range)
  size = range.end - range.begin
  size += 1 unless range.exclude_end?
  size = 0 if size < 0
  size
end

.on_node(syms, sexp, excludes = []) {|sexp| ... } ⇒ Object

Yields:

  • (sexp) 


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# File 'lib/rubocop/cop/util.rb', line 87

def on_node(syms, sexp, excludes = [], &block)
  return to_enum(:on_node, syms, sexp, excludes) unless block_given?

  yield sexp if Array(syms).include?(sexp.type)
  return if Array(excludes).include?(sexp.type)

  sexp.children.each do |elem|
    next unless elem.is_a?(Parser::AST::Node)
    on_node(syms, elem, excludes, &block)
  end
end

.operator?(symbol) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 45

def operator?(symbol)
  OPERATOR_METHODS.include?(symbol)
end

.parentheses?(node) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 82

def parentheses?(node)
  node.loc.respond_to?(:end) && node.loc.end &&
    node.loc.end.is?(')'.freeze)
end

.range_with_surrounding_comma(range, side = :both) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 132

def range_with_surrounding_comma(range, side = :both)
  buffer = @processed_source.buffer
  src = buffer.source

  go_left, go_right = directions(side)

  begin_pos = range.begin_pos
  end_pos = range.end_pos
  begin_pos = move_pos(src, begin_pos, -1, go_left, /,/)
  end_pos = move_pos(src, end_pos, 1, go_right, /,/)

  Parser::Source::Range.new(buffer, begin_pos, end_pos)
end

.range_with_surrounding_space(range, side = :both, with_newline = true) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 146

def range_with_surrounding_space(range, side = :both, with_newline = true)
  buffer = @processed_source.buffer
  src = buffer.source

  go_left, go_right = directions(side)

  begin_pos = range.begin_pos
  end_pos = range.end_pos
  begin_pos = move_pos(src, begin_pos, -1, go_left, /[ \t]/)
  begin_pos = move_pos(src, begin_pos, -1, go_left && with_newline, /\n/)
  end_pos = move_pos(src, end_pos, 1, go_right, /[ \t]/)
  end_pos = move_pos(src, end_pos, 1, go_right && with_newline, /\n/)
  Parser::Source::Range.new(buffer, begin_pos, end_pos)
end

.source_range(source_buffer, line_number, column, length = 1) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 99

def source_range(source_buffer, line_number, column, length = 1)
  if column.is_a?(Range)
    column_index = column.begin
    length = numeric_range_size(column)
  else
    column_index = column
  end

  preceding_line_numbers = (1...line_number)

  line_begin_pos = preceding_line_numbers.reduce(0) do |pos, line|
    pos + source_buffer.source_line(line).length + 1
  end

  begin_pos = line_begin_pos + column_index
  end_pos = begin_pos + length

  Parser::Source::Range.new(source_buffer, begin_pos, end_pos)
end

.strip_quotes(str) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 49

def strip_quotes(str)
  if str[0] == '"' || str[0] == "'"
    str[0] = ''
  else
    # we're dealing with %q or %Q
    str[0, 3] = ''
  end
  str[-1] = ''

  str
end

.to_string_literal(string) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 237

def to_string_literal(string)
  if double_quotes_required?(string)
    string.inspect
  else
    "'#{string.gsub('\\') { '\\\\' }}'"
  end
end

.to_symbol_literal(string) ⇒ Object 



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# File 'lib/rubocop/cop/util.rb', line 245

def to_symbol_literal(string)
  if string =~ /\s/ || double_quotes_required?(string)
    ":#{to_string_literal(string)}"
  else
    ":#{string}"
  end
end

.within_node?(inner, outer) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rubocop/cop/util.rb', line 184

def within_node?(inner, outer)
  o = outer.is_a?(Node) ? outer.source_range : outer
  i = inner.is_a?(Node) ? inner.source_range : inner
  i.begin_pos >= o.begin_pos && i.end_pos <= o.end_pos
end