esbuild-plugin-inline-webworker

README.md

esbuild-plugin-inline-webworker

Usage

// ./index.ts
import workerSrc from 'inline-worker:./worker.ts';
let worker = new Worker(workerSrc);
worker.onmessage = e => console.log(e.data); // 'world'

// ./util.ts
export const hello = () => 'world';

// ./worker.ts
import { hello } from './util.ts';
postMessage(hello());

// ./build.js
import esbuild from 'esbuild';
import { PluginInlineWorker } from './plugin-inline-webworker.js';

esbuild.build({
  entryPoints: ['./index.ts'],
  bundle: true,
  format: 'esm',
  plugins: [PluginInlineWorker()],
})

node build
# // inline-worker:/Users/hms-manzt/demos/esbuild-plugin-inline-webworker/worker
# var worker_default = "data:application/javascript;base64,KCgpPT57dmFyIG89KCk9PiJ3b3JsZCI7cG9zdE1lc3NhZ2UobygpKTt9KSgpOwo=";
# 
# // index.ts
# var worker = new Worker(worker_default);
# worker.onmessage = (e) => console.log(e.data);

plugin-inline-webworker.js

import esbuild from "esbuild";
import { resolve } from "path";

/**
 * @param {Pick<import('esbuild').BuildOptions, 'minify' | 'format' | 'plugins'>}
 * @return {import('esbuild').Plugin}
 */
export const PluginInlineWorker = (opt = {}) => {
	const namespace = "inline-worker";
	const prefix = `${namespace}:`;
	return {
		name: namespace,
		setup(build) {
			build.onResolve({ filter: new RegExp(`^${prefix}`) }, (args) => {
				return {
					path: resolve(args.resolveDir, args.path.slice(prefix.length)),
					namespace,
				};
			});
			build.onLoad({ filter: /.*/, namespace }, async (args) => {
				const { outputFiles } = await esbuild.build({
					entryPoints: [args.path],
					bundle: true,
					write: false,
					format: opt.format || "iife",
					minify: opt.minify || true,
					target: build.initialOptions.target,
					plugins: [
						...(build.initialOptions.plugins || []),
						...(opt.plugins || []),
					],
				});
				if (outputFiles.length !== 1) {
					throw new Error("Too many files built for worker bundle.");
				}
				const { contents } = outputFiles[0];
				const base64 = Buffer.from(contents).toString("base64");
				return {
					loader: "js",
					contents: `export default "data:application/javascript;base64,${base64}";`,
				};
			});
		},
	};
};