condition        ConditionWithContextFunc
		waitFunc         func() waitFunc
		attemptsExpected int
		errExpected      error
	}{
		{
			name:    "condition returns done=true on first attempt, no retry is attempted",
			context: defaultContext,
			condition: ConditionWithContextFunc(func(context.Context) (bool, error) {
				return true, nil
			}),

func Command(usage CmdUsage, run func(*State, ...string) (WaitFunc, error)) Cmd {
	return &funcCmd{
		usage: usage,
		run:   run,
	}
}

// A funcCmd implements Cmd using a function value.
type funcCmd struct {
	usage CmdUsage
	run   func(*State, ...string) (WaitFunc, error)
}

func (c *funcCmd) Run(s *State, args ...string) (WaitFunc, error) {
	return c.run(s, args...)
}

func scriptCC(cmdExec script.Cmd) script.Cmd {
	return script.Command(
		script.CmdUsage{
			Summary: "run the platform C compiler",
			Args:    "args...",
		},
		func(s *script.State, args ...string) (script.WaitFunc, error) {
			b := work.NewBuilder(s.Getwd())
			wait, err := cmdExec.Run(s, append(b.GccCmd(".", ""), args...)...)
			if err != nil {
				return wait, err
			}

	// a WaitFunc that will be called to obtain the result of the command and
	// update the engine's stdout and stderr buffers.
	//
	// Run itself and the returned WaitFunc may inspect and/or modify the State,
	// but the State's methods must not be called concurrently after Run has
	// returned.
	//
	// Run may retain and access the args slice until the WaitFunc has returned.

func Skip() script.Cmd {
	return script.Command(
		script.CmdUsage{
			Summary: "skip the current test",
			Args:    "[msg]",
		},
		func(_ *script.State, args ...string) (script.WaitFunc, error) {
			if len(args) > 1 {
				return nil, script.ErrUsage
			}
			if len(args) == 0 {
				return nil, skipError{""}
			}
			return nil, skipError{args[0]}
		})
}