I'm trying to use JS engine on Mongoose but I have issue on basic keywords. There several keywords that fail when I run my JS script, such try...catch..., switch...case..., and delete obj.prop. Are those keywords not supported? Thanks.
As it is clearly stated at https://github.com/cesanta/mjs,
not all ES6 constructs and keywords are supported.
Particulary ones that you've mentioned, are not supported.