@camertron/opal-esm

What is this thing?

This package contains a copy of the Opal runtime, packaged as a series of ESM modules. Opal is normally evaluated directly on the page and thus attaches itself to window. This library prevents that behavior and instead allows importing and creating locally-scoped instances of the runtime.

Usage

Import Opal using a standard ESM import statement:

import { Opal } from "@camertron/opal-esm";

Opal.Kernel.$puts("Hello, world!");

Importing stdlib modules

Opal includes an implementation of the Ruby standard library. To make these modules available to your ES module, all you have to do is import them.

import { Opal } from "@camertron/opal-esm";
import "@camertron/opal-esm/base64"

Opal.require("base64");

const base64_module = Opal.Kernel.$const_get("Base64");
const encoded = Opal.send(base64_module, "encode64", ["foobar"]);

console.log(encoded)  // prints "Zm9vYmFy\n"

Isolation

Note that, although opal-esm allows the Opal runtime to be imported without modifying window, separate imports do not create more than one copy of the Ruby runtime. All requires, etc affect the same execution context.

Running Tests

npm test should do the trick.

License

Licensed under the MIT license. See LICENSE for details.

Authors

• Cameron C. Dutro: http://github.com/camertron