🌐 bx - a browser runner
With Node.js, Deno or Bun there are so many JavaScript environments to choose from. However, nothing is as good as the browser environment. bx
gives you an execution runtime for the browser.
Install
No install needed, just run it directly via npx
, e.g.:
npx bx "console.log(navigator.userAgent)"
Usage
With bx
you can easily run scripts (JS or TS) within different browser environments:
> echo "console.log(navigator.userAgent)" &> script.js
> npx bx ./script.js
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/121.0.0.0 Safari/537.36
You can easily switch browsers via the --browserName
parameter:
> npx bx ./script.js --browserName firefox
Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:121.0) Gecko/20100101 Firefox/121.0
It even allows you to run .html
files, e.g. given this file:
<script type="module">
console.log(document.querySelector("b").textContent);
</script>
<b>Hello World!</b>
Running this with bx
results in:
> npx bx ./html.html
Hello World!
Run Programmatically
You can also run bx
programmatically, e.g. to hydrate components within the browser. For example, to hydrate a Lit component through a Koa server, you can run this script:
import path from "node:path";
import Koa from "koa";
import { run } from "bx";
const __dirname = path.dirname(new URL(import.meta.url).pathname);
const app = new Koa();
app.use(async (ctx) => {
if (ctx.path === "/favicon.ico") {
return;
}
ctx.body = await run(async () => {
const { render } = await import("@lit-labs/ssr");
const { html } = await import("lit");
await import("./component.ts");
const dom = await render(html`<simple-greeting></simple-greeting>`);
return Array.from(dom).join("\n");
}, {
browserName: "chrome",
rootDir: __dirname,
});
});
app.listen(3000);
console.log("Server running at http://localhost:3000/");
Session Management
If you like to speed up your execution, you can create browser sessions on your system and run scripts through them immediately without having to spin up the browser. You can create a session via:
npx bx session --browserName chrome
npx bx session --browserName chrome --name chrome
You can now run scripts faster by providing a session name:
npx bx ./script.ts --sessionName chrome
To view all opened sessions, run:
npx bx session
Kill specific or all sessions via:
npx bx session --kill chrome
npx bx session --killAll