Indent as deep as case.
^[link]

Align function parameters either all on
the same line or one per line.^[link]

  # bad
  def self.create_translation(phrase_id, phrase_key, target_locale,
                              value, user_id, do_xss_check, allow_verification)
    ...
  end
  # good
  def self.create_translation(phrase_id,
                              phrase_key,
                              target_locale,
                              value,
                              user_id,
                              do_xss_check,
                              allow_verification)
    ...
  end
  # good
  def self.create_translation(
    phrase_id,
    phrase_key,
    target_locale,
    value,
    user_id,
    do_xss_check,
    allow_verification
  )
    ...
  end

Indent succeeding lines in multi-line
boolean expressions.^[link]

  # bad
  def is_eligible?(user)
    program_not_expired
  end
  # good
  def is_eligible?(user)
    Trebuchet.current.launch?(ProgramEligibilityHelper::PROGRAM_TREBUCHET_FLAG) &&
      is_in_program?(user) &&
      program_not_expired
  end

Never leave trailing whitespace.
^[link]

When making inline comments, include a
space between the end of the code and the start of your comment.
^[link]

  # bad
  result = func(a, b)# we might want to change b to c
  # good
  result = func(a, b) # we might want to change b to c

  sum = 1 + 2
  a, b = 1, 2
  1 > 2 ? true : false; puts 'Hi'
  [1, 2, 3].each { |e| puts e }

Never include a space before a comma.
^[link]

Do not include space inside block
parameter pipes. Include one space between parameters in a block.
Include one space outside block parameter pipes.
^[link]

  # bad
  {}.each { | x,  y |puts x }
  # good
  {}.each { |x, y| puts x }

Do not leave space between ! and its
argument.^[link]

  !something

No spaces after (, [ or before ], ).
^[link]

  some(arg).other
  [1, 2, 3].length

Omit whitespace when doing
string interpolation.^[link]

  var = "This #{ foobar } is interpolated."
  var = "This #{foobar} is interpolated."

Add a new line after if conditions spanning
multiple lines to help differentiate between the conditions and the body.
^[link]

  if @reservation_alteration.checkin == @reservation.start_date &&
     @reservation_alteration.checkout == (@reservation.start_date + @reservation.nights)
    redirect_to_alteration @reservation_alteration
  end

Add a new line after conditionals,
blocks, case statements, etc.^[link]

  if robot.is_awesome?
    send_robot_present
  end
  robot.add_trait(:human_like_intelligence)

Don’t include newlines between areas
of different indentation (such as around class or module bodies).
^[link]

  # bad
  class Foo
    def bar
      # body omitted
    end
  end
  # good
  class Foo
    def bar
      # body omitted
    end
  end

Include one, but no more than one, new
line between methods.^[link]

  def a
  end
  end

Use a single empty line to break between
statements to break up methods into logical paragraphs internally.
^[link]