taskgenius_taskgenius-plugin/packages/esbuild-plugin-inline-worker/index.ts

import { type BuildOptions, type PluginBuild, build } from "esbuild";
import findCacheDir from "find-cache-dir";
import fs from "fs";
import path from "path";

export type InlineWorkerPluginConfig = {
	buildOptions?: BuildOptions;
	workerName?: string;
	workerArguments?: WorkerOptions;
};

export default function inlineWorkerPlugin(
	workerPluginConfig: InlineWorkerPluginConfig = {}
) {
	return {
		name: "esbuild-plugin-inline-worker",

		setup(build: PluginBuild) {
			build.onLoad(
				{ filter: /\.worker.(js|jsx|ts|tsx)$/ },
				async ({ path: workerPath }) => {
					// const workerCode = await fs.promises.readFile(workerPath, {
					//   encoding: 'utf-8',
					// });

					const workerCode = await buildWorker(
						workerPath,
						workerPluginConfig
					);
					return {
						contents: `import inlineWorker from '__inline-worker'
export default function Worker() {
  return inlineWorker(${JSON.stringify(workerCode)});
}
`,
						loader: "js",
					};
				}
			);

			const options: WorkerOptions = {
				name: workerPluginConfig.workerName || undefined,
				...workerPluginConfig.workerArguments,
			};

			const inlineWorkerFunctionCode = `
export default function inlineWorker(scriptText) {
  const blob = new Blob([scriptText], {type: 'text/javascript'});
  const url = URL.createObjectURL(blob);
  const worker = new Worker(url, ${JSON.stringify(options)});
  URL.revokeObjectURL(url);
  return worker;
}
`;

			build.onResolve({ filter: /^__inline-worker$/ }, ({ path }) => {
				return { path, namespace: "inline-worker" };
			});
			build.onLoad({ filter: /.*/, namespace: "inline-worker" }, () => {
				return { contents: inlineWorkerFunctionCode, loader: "js" };
			});
		},
	};
}

const cacheDir = findCacheDir({
	name: "esbuild-plugin-inline-worker",
	create: true,
});

async function buildWorker(
	workerPath: string,
	pluginConfig: InlineWorkerPluginConfig
) {
	const scriptNameParts = path.basename(workerPath).split(".");
	scriptNameParts.pop();
	scriptNameParts.push("js");
	const scriptName = scriptNameParts.join(".");
	if (!cacheDir) {
		throw new Error(
			"Cache directory not found. Please ensure 'find-cache-dir' is installed."
		);
	}
	const bundlePath = path.resolve(cacheDir, scriptName);

	if (pluginConfig.buildOptions) {
		delete pluginConfig.buildOptions.entryPoints;
		delete pluginConfig.buildOptions.outfile;
		delete pluginConfig.buildOptions.outdir;
	}

	await build({
		entryPoints: [workerPath],
		bundle: true,
		minify: true,
		outfile: bundlePath,
		target: "es2017",
		format: "esm",
		...pluginConfig.buildOptions,
	});

	return fs.promises.readFile(bundlePath, { encoding: "utf-8" });
}