es_runtime

es_runtime is a crate aimed at making it possible for rust developers to integrate an ECMA-Script engine in their rust projects

The engine used is the Mozilla SpiderMonkey engine (https://developer.mozilla.org/en-US/docs/Mozilla/Projects/SpiderMonkey)

This project was started as a hobby project for me to learn rust. I hope some of you find it useful to learn about using spidermonkey from rust.

status

Nowhere near production ready, it is untested and i'm pretty sure i created some memory leaks in the unsafe sections...

It works with the mozjs crate version 0.10.1 which is already pretty old but there are no newer releases, when i get more comfortable with spidermonkey and mozjs i'll see about using a git pull of a newer version.

Please see the CHANGELOG for what's new.

Currently i'm working towards creating a 0.1 version which has a couple of goals

• Get a grip on when to use rooted values (Handle) and when to use Values (JSVal)
• Easy loading script files
• Error handling (get ES errors in rust with filename/linenumber etc)
• Adding rust function to the engine so they are callable from ECMA-Script
  • Blocking
  • Non-blocking (returns a Promise in script)
• Easy way to call ECMA-Script functions from rust
  • By name (run_global_function())
  • By object name and name (myObj.doSomething())
  • Passing params from rust
• Getting data from engine as primitives or Vecs and Maps
  • Primitives
  • Objects from and to Maps
  • Arrays as Vecs
• Working console (logging)
• Working Promises in Script
• Waiting for Promises from rust
• import/export statement support
  • cache modules
• No more memory leaks

0.2 goals

• Use PersistentRooted instead of deprecated Add*Root and Remove*Root
• typedArrays from and to Vecs

future goals / todo's

• Interactive Debugging
• Profiling
• TypeScript support
• much more

Other plans

I'm also working on a more feature rich runtime with a commandline tool and also an application server based on this runtime

These are in a very early testing stage and may become available later as a separate project.

I'dd like to hear what you would want to see in this project, please drop me a line @ incoming+drfos-es-runtime-17727229-issue-@incoming.gitlab.com

examples

Cargo.toml

[dependencies]
es_runtime = "0.0.5"

my_app.rs

    #[test]
    fn example() {
        // start a runtime

        let rt = EsRuntimeWrapper::new();
    
        // run the garbage collector every 5 secs
        rt.start_gc_deamon(Duration::from_secs(5));

        // create an example object

        rt.eval_sync("this.myObj = {a: 1, b: 2};", "test1.es")
            .ok()
            .unwrap();

        // register a native rust method

        rt.register_op(
            "my_rusty_op",
            Box::new(|_sm_rt, args: Vec<EsValueFacade>| {
                let a = args.get(0).unwrap().get_i32();
                let b = args.get(1).unwrap().get_i32();
                Ok(EsValueFacade::new_i32(a * b))
            }),
        );

        // call the rust method from ES

        rt.eval_sync(
            "this.myObj.c = esses.invoke_rust_op_sync('my_rusty_op', 3, 7);",
            "test2.es",
        )
        .ok()
        .unwrap();

        let c: Result<EsValueFacade, EsErrorInfo> =
            rt.eval_sync("(this.myObj.c);", "test3.es");

        assert_eq!(&21, c.ok().unwrap().get_i32());

        // define an ES method and calling it from rust

        rt.eval_sync("this.my_method = (a, b) => {return a * b;};", "test4.es")
            .ok()
            .unwrap();

        let args = vec![EsValueFacade::new_i32(12), EsValueFacade::new_i32(5)];
        let c_res: Result<EsValueFacade, EsErrorInfo> = rt.call_sync("my_method", args);
        let c: EsValueFacade = c_res.ok().unwrap();
        assert_eq!(&60, c.get_i32());
    }

a word on compiling

Currently I have only compiled this on and for a 64 bit linux machine (I use openSUSE)

Besides rust you'll need to install the following packages to compile the mozjs crate

• gcc-7
• autoconf2.13
• automake
• clang
• python

for more detailed info please visit https://github.com/servo/mozjs#building

howtos

HOWTO