List of some weirdness and gotchas

gotchas.md

Ruby

1. Outside ENV strings are frozen:

example.rb:

ENV['foo'].strip!

Run:

foo='bar' ruby example.rb 
`strip!': can't modify frozen String (RuntimeError)

2. Assigning anything but String to ENV produces TypeError

ENV['foo'] = :bar
# => `[]=': no implicit conversion of Symbol into String (TypeError)

ENV['foo'] = 5
# => `[]=': no implicit conversion of Fixnum into String (TypeError)

ENV['foo'] = {}
# => `[]=': no implicit conversion of Hash into String (TypeError)
 

---

Chef

1. Logging true/false:

Chef::Log.warn(true)
=> WARN: true
Chef::Log.warn(false)
=> WARN: nil # Gotcha!