.env
env = sys.env
allows reading environment variables using plain indexing
assert.equals 'string', type env.HOME
assert.equals 'string', type env['HOME']
assert.equals os.getenv('HOME'), env.HOME
allows setting variables via assignment
env.MY_VAR = 'myval'
assert.equals 'myval', env.MY_VAR
assert.equals 'myval', os.getenv('MY_VAR')
allows unsetting variables using a nil assignment
env.MY_VAR = 'myval'
assert.equals 'myval', os.getenv('MY_VAR')
env.MY_VAR = nil
assert.is_nil env.MY_VAR
assert.is_nil os.getenv('MY_VAR')
allows iterating over the env using pairs
env.MY_VAR = 'yowser!'
as_table = {k,v for k,v in pairs env}
assert.equals 'yowser!', as_table.MY_VAR