I’d like to know which ECMA edition do the two versions about mozjs(mozjs-52.9.1, mozjs-1.7) obey?
hello @Jim_Ryna
not sure if i got your right but would that help you
https://caniuse.com/#search=ECMA
and does not mean that certain browser enable some feature that mean it implement all the value and options
use the site i mentioned and also the mdn to look for the value /option / property you want and see if it enable on your browser
hope that help and have a nice day