quickjs_runtime

quickjs_runtime is a library for quickly getting started with embedding a javascript engine in your rust project.

DISCLAIMER: This project is far from what I would call "Battle Tested", use at your own risk.

quickjs_runtime focuses purely on making quickjs easy to use and does not add any additional features, that's where these projects come in: * A more feature-rich runtime: GreenCopperRuntime. * The commandline client: GreenCopperCmd. * And then there is GreenCopper which aspires to be a full fledged application platform: GreenCopperServer.

This project is heavily inspired by the awesome quickjs wrapper at theduke/quickjs-rs and still uses its low level bindings libquickjs-sys.

The big difference to quickjs-rs is that quickjs_runtime executes all quickjs related code in a dedicated single-threaded EventLoop.

Please see the DOCS for all inner workings

This lib serves two main goals:

1. Provide simple utils for working with quickjs (these are located in the quickjs_utils mod)

• The QuickJsRuntime struct, this is to be used from a single thread
• E.g. objects::setproperty(), functions::invokefunc()
• Wrap JSValue to provide reference counting (+1 on init, -1 on drop) (JSValueRef)
• Pass a module loader

2. Wrap quickjs for use as a ready to go JavaScript Runtime

• This is the EsRuntime struct, it provides an EventQueue which has a thread_local QuickJsRuntime
• All values are copied or abstracted in an EsValueFacade
• So no need to worry about Garbage collection
• evaluate script and invoke functions while waiting for results blocking or with async/await
• Get Promise result blocking or with async/await

What works?

Script and Modules

• console (.log/info/debug/trace/error) (docs)
• Eval script (docs)
• Create promises in JavaScript which execute async
• Eval modules (docs)
• Load modules (dynamic and static) (docs)
• fetch api (docs)
• setImmediate
• setTimeout/Interval (and clear)

Rust-Script interoperability

• Return Promises from rust functions and resolve them from rust (docs)
• Add functions from rust (docs)
• Invoke JS functions from rust (docs)
• Pass primitives, objects and arrays from and to rust (docs)
• Create Classes from rust (docs)
• async/await support on eval/call_function/promise resolution (docs)
• import native Modules (e.g. dynamic loading of rust functions or Proxy classes) (docs)

Future / Todo

• Worker support
• WebAssembly support
• Macro / IFDef support
• Pre processing (for e.g. typescript)

goals

Same goals as https://github.com/HiRoFa/es_runtime but with using quickjs

so * slower js

but

• smaller footprint
• much faster compilation

For some of my projects those are a big plus!

examples

Here are some quickstarts:

Cargo.toml

toml [dependencies] quickjs_runtime = "0.3" log = "0.4.11" simple-logging = "2.0.2"

main.rs

```rust use quickjsruntime::esruntimebuilder::EsRuntimeBuilder; use quickjsruntime::esscript::EsScript; use log::LevelFilter; use futures::executor::blockon; use std::sync::Arc; use quickjsruntime::esruntime::EsRuntime;

async fn test(rt: Arc){ let res = rt.eval(EsScript::new( "basics.es", "7 * 12;", )).await.ok().unwrap();

assert_eq!(res.get_i32(), 84);

}

fn main() { simplelogging::logto_stderr(LevelFilter::Info);

let rt = EsRuntimeBuilder::new()
    .build();

block_on(test(rt));

} ```

invoke a js method from rust

rust let res = rt.call_function(vec!["myAppUtils"], "some_func", es_args![8, 7]).await; match res { Ok(val) => log::info!("8*7 in JavaScript = {}", val.get_i32()), Err(e) => log::error!("script failed: {}", e), }

add a function from rust and invoke it

```rust rt.setfunction(vec!["nl", "my", "utils"], "methodA", |args| { if args.len() != 2 || !args.get(0).unwrap().isi32() || !args.get(1).unwrap().isi32() { Err(EsError::newstr( "i'd really like 2 args of the int32 kind please", )) } else { let a = args[0].geti32(); let b = args[1].geti32(); log::info!("rust is multiplying {} and {}", a, b); Ok((a * b).toesvaluefacade()) } }) .ok() .expect("setfunction failed");

let method_a_res = rt.eval(EsScript::new(
    "test_func.es",
    "(nl.my.utils.methodA(13, 56));",
)).await;

match method_a_res {
    Ok(val) => {
        assert_eq!(val.get_i32(), 13 * 56);
    }
    Err(e) => {
        panic!("test_func.es failed: {}", e);
    }
}

```

eval a module

rust rt.eval_module(EsScript::new( "my_app.mes", "\ import {foo} from 'example.mes';\ console.log('static foo is ' + foo);\ ", )).await .ok() .expect("module failed");

eval a module with a dynamic import

```rust

rt.eval_module(EsScript::new(
    "my_app2.es",
    "\
import('example.mes')\
.then((example_module) => {\
    console.log('dynamic foo is ' + example_module.foo);\
});\
",
)).await
.ok()
.expect("script failed");

```

get a function from js and invoke it in rust

```rust rt.setfunction(vec!["nl", "my", "utils"], "methodB", |mut args| { if args.len() != 1 || !args[0].isfunction() { Err(EsError::newstr( "i'd really like 1 arg of the function kind please", )) } else { let consumerfunc = args.remove(0);

        // invoke the func async, just because we can
        std::thread::spawn(move || {
            consumer_func
                .invoke_function_sync(es_args![19, 17])
                .ok()
                .expect("func failed");
        });

        Ok(quickjs_es_runtime::esvalue::EsNullValue {}.to_es_value_facade())
    }
})
.ok()
.expect("set_function failed");

rt.eval(EsScript::new(
    "test_func2.es",
    "(nl.my.utils.methodB(function(a, b){console.log('consumer was called with ' +a + ', ' + b);}));",
)).await.ok().expect("test_func2.es failed");

// wait a sec for the async onvoker to run
std::thread::sleep(Duration::from_secs(1));

```