Style conventions

• Two spaces, no tabs.

• No trailing whitespace. Blank lines should not have any space.

• Indent after private/protected.

• Prefer &&/|| over and/or.

• Prefer class « self block over self.method for class methods.

• my_method(my_arg) not my_method( my_arg ) or my_method my_arg.

• a = b and not a=b.

• { a + b } and not {a + b}

• "string#{ expr }" and not "string#{expr}"

• -> symbol over lambda

• Ruby 1.9 hash syntax { key: :value } over Ruby 1.8 hash syntax { :key => :value }

• Alphabetize the class methods to keep them organized.

• Follow the conventions you see used in the source already.

• avoid double negations

• Indent when as deep as case. I know that many would disagree with this one, but it's the style established in both "The Ruby Programming Language" and "Programming Ruby".

# good
case
when song.name == 'Misty'
  puts 'Not again!'
when song.duration > 120
  puts 'Too long!'
when Time.now.hour > 21
  puts "It's too late"
else
  song.play
end

• When assigning the result of a conditional expression to a variable, preserve the usual alignment of its branches.

# good - it's apparent what's going on
kind = case year
       when 1850..1889 then 'Blues'
       when 1890..1909 then 'Ragtime'
       when 1910..1929 then 'New Orleans Jazz'
       when 1930..1939 then 'Swing'
       when 1940..1950 then 'Bebop'
       else 'Jazz'
       end

result = if some_cond
           calc_something
         else
           calc_something_else
         end

# good (and a bit more width efficient)
kind =
  case year
  when 1850..1889 then 'Blues'
  when 1890..1909 then 'Ragtime'
  when 1910..1929 then 'New Orleans Jazz'
  when 1930..1939 then 'Swing'
  when 1940..1950 then 'Bebop'
  else 'Jazz'
  end

result =
  if some_cond
    calc_something
  else
    calc_something_else
  end

• Use one expression per branch in a ternary operator. This also means that ternary operators must not be nested. Prefer if/else constructs in these cases.

# bad
some_condition ? (nested_condition ? nested_something : nested_something_else) : something_else

# good
if some_condition
  nested_condition ? nested_something : nested_something_else
else
  something_else
end

• Leverage the fact that if and case are expressions which return a result.

# bad
if condition
  result = x
else
  result = y
end

# good
result =
  if condition
    x
  else
    y
  end

other references ruby style