I’m mostly using Ruby to write Opscode Chef Cookbooks. There are a lot of hashes of hashes that contain attributes or Data Bags. Things that look like:
app['rds_database'][environment]['rds_name']
If I wanted to test if this value is set I couldn’t safely just say:
if app['rds_database'][environment]['rds_name']
because in some cases
if app['rds_database']
or
if app['rds_database'][environment] [...]

