Re: ESR52 SpiderMonkey & ES6

On Saturday, June 23, 2018 at 3:25:33 PM UTC-4, Jason Orendorff wrote:
> You're right, this is super complicated. :-\
> 
> Well, I guess the first task is to get an error message. There's no pending
> exception when these functions return false?
> 
> -j
> 
> 
> On Wed, Jun 20, 2018 at 3:11 PM, Kent Williams <[email protected]>
> wrote:
> 
> > Been beating my head on this for a couple of days.
> >
> > I'm trying to get ES6 module support working with ESR52 SpiderMonkey.
> >
> > I can run plain scripts just fine, but if I try using ES6 modules, it
> > breaks.
> >
> > I solved one problem: You can't compile anything 'import' in it without
> > setting the Module resolver with JS::SetModuleResolveHook.
> >
> > Then it turns out you can't use JS::Compile with any code with 'import' in
> > it -- even if it isn't a module itself.
> >
> > But if you use JS::CompileModule, it isn't clear what you have to do to
> > execute the script.
> >
> > What should happen is that you do X (where X is unknown) to execute the
> > script, and then the interpreter handles the 'import' statements in your
> > code by calling the resolve hook.
> >
> > So my problem is X -- if you have to use JS::CompileModule if there are
> > any import statements in a script, how do you execute the script?
> >
> > Looking at the JS Shell code, the resolve hook is actually in a Javascript
> > file.  I tried doing what that file does (ModuleLoader.js) but it doesn't
> > work.  I call ModuleDeclarationInstantiation followed by ModuleEvaluation
> > -- and both fail without any error message. They return false, and there's
> > no apparent error message anywhere.
> >
> > Is it the case that no one uses ES6 modules with SpiderMonkey, except
> > perhaps the Mozilla Browswer & the js shell included?

We have a branch in progress for this in GJS: https://gitlab.gnome.org/GNOME/gjs/merge_requests/150 It's currently still based on ESR52, but the basics do seem to work.
There's some information there that may help you. I believe the module is executed during the ModuleEvaluation step.

Regards,
Philip