A pure javascript shim for WASI

Implementation status: A subset of wasi_snapshot_preview1 is implemented. The rest either throws an exception, returns an error or is incorrectly implemented.

Usage

npm install @bjorn3/browser_wasi_shim --save

import { WASI, File, OpenFile, PreopenDirectory } from "@bjorn3/browser_wasi_shim";

let args = ["bin", "arg1", "arg2"];
let env = ["FOO=bar"];
let fds = [
    new OpenFile(new File([])), // stdin
    new OpenFile(new File([])), // stdout
    new OpenFile(new File([])), // stderr
    new PreopenDirectory(".", {
        "example.c": new File(new TextEncoder("utf-8").encode(`#include "a"`)),
        "hello.rs": new File(new TextEncoder("utf-8").encode(`fn main() { println!("Hello World!"); }`)),
    }),
];
let wasi = new WASI(args, env, fds);

let wasm = await WebAssembly.compileStreaming(fetch("bin.wasm"));
let inst = await WebAssembly.instantiate(wasm, {
    "wasi_snapshot_preview1": wasi.wasiImport,
});
wasi.start(inst);

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.