{"initial":{"source":"A😀B","spans":[{"id":"face","start":1,"end":3,"text":"😀"}]},"counterexample":{"source":"A😀B","spans":[{"id":"face","start":1,"end":2,"text":"😀"}]},"tests":[{"name":"surrogate pair span","input":{"source":"A😀B","spans":[{"id":"face","start":1,"end":3,"text":"😀"}]},"expected":{"pass":true,"summary":"Every UTF-16 offset reproduces its recorded span.","checks":[{"name":"face","pass":true}]}},{"name":"wrong code-point boundary","input":{"source":"A😀B","spans":[{"id":"face","start":1,"end":2,"text":"😀"}]},"expected":{"pass":false,"summary":"1 span offset(s) do not reproduce recorded text.","checks":[{"name":"face","pass":false}]}},{"name":"end boundary","input":{"source":"A😀B","spans":[{"id":"last","start":3,"end":4,"text":"B"}]},"expected":{"pass":true,"summary":"Every UTF-16 offset reproduces its recorded span.","checks":[{"name":"last","pass":true}]}}]}