12 - Misc

  • Write ruby -w safe code.

  • Avoid hashes as optional parameters. Does the method do too much? (Object initializers are exceptions for this rule).

  • Avoid methods longer than 10 LOC (lines of code). Ideally, most methods will be shorter than 5 LOC. Empty lines do not contribute to the relevant LOC.

  • Avoid parameter lists longer than three or four parameters.

  • If you really need "global" methods, add them to Kernel and make them private.

  • Use module instance variables instead of global variables.

    # bad
$foo_bar = 1

# good
module Foo
  class << self
    attr_accessor :bar
  end
end

Foo.bar = 1

  • Use OptionParser for parsing complex command line options and ruby -s for trivial command line options.

  • Prefer Time.now over Time.new when retrieving the current system time.

  • Code in a functional way, avoiding mutation when that makes sense.

  • Do not mutate parameters unless that is the purpose of the method.

  • Avoid more than three levels of block nesting.

  • Be consistent. In an ideal world, be consistent with these guidelines.

  • Use common sense.