Crate javy_apis

source ·
Expand description

JS APIs for Javy.

This crate provides JS APIs you can add to Javy.

Example usage:

use javy::{quickjs::JSValue, Runtime};
use javy_apis::RuntimeExt;

let runtime = Runtime::new_with_defaults()?;
let context = runtime.context();
context.global_object()?.set_property(
   "print",
   context.wrap_callback(move |_ctx, _this, args| {
       let str = args
           .first()
           .ok_or(anyhow!("Need to pass an argument"))?
           .to_string();
       println!("{str}");
       Ok(JSValue::Undefined)
   })?,
)?;
context.eval_global("hello.js", "print('hello!');")?;

If you want to customize the runtime or the APIs, you can use the Runtime::new_with_apis method instead to provide a javy::Config for the underlying Runtime or an APIConfig for the APIs.

§Features

  • console - Registers an implementation of the console API.
  • text_encoding - Registers implementations of TextEncoder and TextDecoder.
  • random - Overrides the implementation of Math.random to one that seeds the RNG on first call to Math.random. This is helpful to enable when using Wizer to snapshot a javy::Runtime so that the output of Math.random relies on the WASI context used at runtime and not the WASI context used when Wizening. Enabling this feature will increase the size of the Wasm module that includes the Javy Runtime and will introduce an additional hostcall invocation when Math.random is invoked for the first time.
  • stream_io - Registers implementations of Javy.IO.readSync and Javy.IO.writeSync.

Structs§

  • APIConfig
    A configuration for APIs added in this crate.

Traits§

Functions§