ruby-head-wasm-wasi
WebAssembly port of CRuby with WASI.
This package distributes the latest master
branch of CRuby.
Installation
For installing ruby-head-wasm-wasi family, just run this command in your shell:
$ npm install --save ruby-head-wasm-wasi@latest
# or if you want the nightly snapshot
$ npm install --save ruby-head-wasm-wasi@next
# or you can specify the exact snapshot version
$ npm install --save ruby-head-wasm-wasi@2.3.0-2023-11-26-a
Quick Start (for Node.js)
See the example project for more details.
import fs from "fs/promises";
import { DefaultRubyVM } from "@ruby/wasm-wasi/dist/node.cjs.js";
const main = async () => {
const binary = await fs.readFile(
// Tips: Replace the binary with debug info if you want symbolicated stack trace.
// (only nightly release for now)
// "./node_modules/ruby-head-wasm-wasi/dist/ruby.debug+stdlib.wasm"
"./node_modules/ruby-head-wasm-wasi/dist/ruby.wasm"
);
const module = await WebAssembly.compile(binary);
const { vm } = await DefaultRubyVM(module);
vm.eval(`
luckiness = ["Lucky", "Unlucky"].sample
puts "You are #{luckiness}"
`);
};
main();
Then you can run the example project in your terminal:
$ node --experimental-wasi-unstable-preview1 index.node.js
Quick Start (for Browser)
In browser, you need a WASI polyfill. See the example project for more details.
<html>
<script src="https://cdn.jsdelivr.net/npm/@ruby/wasm-wasi@latest/dist/browser.umd.js"></script>
<script>
const { DefaultRubyVM } = window["ruby-wasm-wasi"];
const main = async () => {
// Fetch and instantiate WebAssembly binary
const response = await fetch(
// Tips: Replace the binary with debug info if you want symbolicated stack trace.
// (only nightly release for now)
// "https://cdn.jsdelivr.net/npm/ruby-head-wasm-wasi@next/dist/ruby.debug+stdlib.wasm"
"https://cdn.jsdelivr.net/npm/ruby-head-wasm-wasi@latest/dist/ruby.wasm"
);
const buffer = await response.arrayBuffer();
const module = await WebAssembly.compile(buffer);
const { vm } = await DefaultRubyVM(module);
vm.printVersion();
vm.eval(`
require "js"
luckiness = ["Lucky", "Unlucky"].sample
JS::eval("document.body.innerText = '#{luckiness}'")
`);
};
main();
</script>
<body></body>
</html>
GC limitation with JavaScript interoperability
Since JavaScript's GC system and Ruby's GC system are separated and not cooperative, they cannot collect cyclic references between JavaScript and Ruby objects.
The following code will cause a memory leak:
class JNode {
setRNode(rnode) {
this.rnode = rnode;
}
}
jnode = new JNode();
rnode = vm.eval(`
class RNode
def set_jnode(jnode)
@jnode = jnode
end
end
RNode.new
`);
rnode.call("set_jnode", vm.wrap(jnode));
jnode.setRNode(rnode);
APIs
Table of Contents
RubyVM
A Ruby VM instance
Examples
const wasi = new WASI();
const vm = new RubyVM();
const imports = {
wasi_snapshot_preview1: wasi.wasiImport,
};
vm.addToImports(imports);
const instance = await WebAssembly.instantiate(rubyModule, imports);
await vm.setInstance(instance);
wasi.initialize(instance);
vm.initialize();
initialize
Initialize the Ruby VM with the given command line arguments
Parameters
-
args
The command line arguments to pass to Ruby. Must be an array of strings starting with the Ruby program name. (optional, default["ruby.wasm","--disable-gems","-e_=0"]
)
setInstance
Set a given instance to interact JavaScript and Ruby's WebAssembly instance. This method must be called before calling Ruby API.
Parameters
-
instance
The WebAssembly instance to interact with. Must be instantiated from a Ruby built with JS extension, and built with Reactor ABI instead of command line.
addToImports
Add intrinsic import entries, which is necessary to interact JavaScript and Ruby's WebAssembly instance.
Parameters
-
imports
The import object to add to the WebAssembly instance
printVersion
Print the Ruby version to stdout
eval
Runs a string of Ruby code from JavaScript
Parameters
-
code
The Ruby code to run
Examples
vm.eval("puts 'hello world'");
const result = vm.eval("1 + 2");
console.log(result.toString()); // 3
Returns any the result of the last expression
evalAsync
Runs a string of Ruby code with top-level JS::Object#await
Returns a promise that resolves when execution completes.
Parameters
-
code
The Ruby code to run
Examples
const text = await vm.evalAsync(`
require 'js'
response = JS.global.fetch('https://example.com').await
response.text.await
`);
console.log(text.toString()); // <html>...</html>
Returns any a promise that resolves to the result of the last expression
wrap
Wrap a JavaScript value into a Ruby JS::Object
Parameters
-
value
The value to convert to RbValue
Examples
const hash = vm.eval(`Hash.new`);
hash.call("store", vm.eval(`"key1"`), vm.wrap(new Object()));
Returns any the RbValue object representing the given JS value
RbValue
A RbValue is an object that represents a value in Ruby
call
Call a given method with given arguments
Parameters
-
callee
name of the Ruby method to call -
args
...any arguments to pass to the method. Must be an array of RbValue
Examples
const ary = vm.eval("[1, 2, 3]");
ary.call("push", 4);
console.log(ary.call("sample").toString());
toPrimitive
- See: https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/Symbol/toPrimitive
Parameters
-
hint
Preferred type of the result primitive value."number"
,"string"
, or"default"
.
toString
Returns a string representation of the value by calling to_s
toJS
Returns a JavaScript object representation of the value
by calling to_js
.
Returns null if the value is not convertible to a JavaScript object.
RbError
Extends Error
Error class thrown by Ruby execution
Building the package from source
The instructions for building a Ruby targeting WebAssembly are available here.
Then, you can run the following command in your shell:
# Check the directory structure of your Ruby build
$ tree -L 3 path/to/wasm32-unknown-wasi-full-js/
path/to/wasm32-unknown-wasi-full-js/
├── usr
│ └── local
│ ├── bin
│ ├── include
│ ├── lib
│ └── share
└── var
└── lib
└── gems
$ ./build-package.sh path/to/wasm32-unknown-wasi-full-js/
Generating "/Users/katei/.ghq/github.com/ruby/ruby.wasm/packages/ruby-head-wasm-wasi/src/bindgen/intrinsics.js"
Generating "/Users/katei/.ghq/github.com/ruby/ruby.wasm/packages/ruby-head-wasm-wasi/src/bindgen/rb-abi-guest.d.ts"
Generating "/Users/katei/.ghq/github.com/ruby/ruby.wasm/packages/ruby-head-wasm-wasi/src/bindgen/rb-abi-guest.js"
Generating "/Users/katei/.ghq/github.com/ruby/ruby.wasm/packages/ruby-head-wasm-wasi/src/bindgen/rb-js-abi-host.d.ts"
Generating "/Users/katei/.ghq/github.com/ruby/ruby.wasm/packages/ruby-head-wasm-wasi/src/bindgen/rb-js-abi-host.js"
src/index.ts → dist/index.umd.js, dist/index.esm.js, dist/index.cjs.js...
created dist/index.umd.js, dist/index.esm.js, dist/index.cjs.js in 682ms