specify posix.sys.times:

- before:

    tms = require "posix.sys.times"

- describe times:

  - before:

      table.unpack = table.unpack or unpack

      times = tms.times

  # posix.times takes an optional string or table as its first

  # argument, followed by zero or more strings only if the first

  # argument was a string; since we can't express that with

  # `badargs.diagnose` do it all manually again...

  - context with bad arguments:

      badargs.diagnose (times, "()")

  - it returns a PosixTms:

      expect (prototype (times ())).to_be "PosixTms"

  - it fetches everything without an argument:

      keys = {

        "tms_utime", "tms_stime", "tms_cutime", "tms_cstime", "elapsed"

      }

      t = times ()

      expect (t).to_contain.a_permutation_of (keys)

      for _, key in ipairs (keys) do

        expect (type (t[key])).to_be "number"

      end