How about this for sorting strings:
item in (items|orderBy:['!name', 'name'])
The advantage (apart from being more concise) is it sorts null & undefined with the blank strings.
In my case I wanted the blanks & nulls & undefineds together at the top (nulls and undefineds by default sort to the bottom), so I used:
item in (items|orderBy:['!!name', 'name'])