Confident Code

Confident Code

• Timid code
  • Prone to digressions
  • Second-guessing itself
• Confident code

  • Intention

  • No provisos or digressions

  • Narrative

    • Gather input
    • Perform work
    • Deliver results
    • Handle failure

  • True duck typing is a confident style

  • If in doubt, coerce

  • to_a isn't in 1.9, use Array()

    require 'delegate' # Ruby std lib

    class WithPath < SimpleDelegator def path case 1 case 2 ... end end

  • Reject unexpected values outright

    • Assert your contract (no DbC framework needed)

    NOTE raise Exception, message, caller # sets context to caller

  • Guard clause to short-circuit, avoids special cases later

    • Or... the Special Case pattern
    • NullObject pattern # Maybe()
    • Hash#fetch to give back a symbol
    • jQuery selectors are confident

  • Instead of returning nil, consider returning a NullObject or other Special Case object

  • Happy path first

  • rescue idiom