JSON="env JSON_EXEC=vm ../../lib/json.js"
JSON0="env JSON_EXEC=vm ../../lib/json.js -o json-0"

echo '{"foo": "bar"}' | $JSON0 -e 'this.foo="baz"'
#    {"foo":"baz"}
echo '{"foo": "bar"}' | $JSON0 -e 'foo="baz"'
#    {"foo":"baz"}
echo '{"age": 38}' | $JSON0 -e 'this.age++'
#    {"age":39}
echo '{"age": 38}' | $JSON0 -e 'age++'
#    {"age":39}

echo '{"one": 1, "two": 2}' | $JSON0 -e 'this.one=undefined'
#    {"two":2}
echo '{"one": 1, "two": 2}' | $JSON0 -e 'one=undefined'
#    {"two":2}

echo ''
echo '{"one": 1, "two": 2}' | $JSON0 -e 'one++' -e 'two++'
#    {"one":2,"two":3}
echo '{"one": 1, "two": 2}' | $JSON -e 'one++' one
#    2

echo ''
echo '[{"first":"Trent","last":"Mick"},{"first":"Andrew","last":"Dlugan"}]' \
    | $JSON0 -a -e 'name=[first,last].join(" ");first=undefined;last=undefined'
#    [{"name":"Trent Mick"},{"name":"Andrew Dlugan"}]

echo ''
echo '{"foo": "bar"}' | $JSON -e 'foo foo' 2>&1 | grep SyntaxError
#    SyntaxError: Unexpected identifier