captoys/toybox/test/vat.test.js

/** @file toybox end to end: a real workerd, an admin socket, a public port. */
import { spawn } from "node:child_process";
import { mkdir, mkdtemp, readFile, rm } from "node:fs/promises";
import { request } from "node:http";
import { createServer } from "node:net";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { after, before, test } from "node:test";
import assert from "node:assert/strict";

const here = new URL("..", import.meta.url).pathname;
// the package binary, not the .bin shim: the shim forks it, so a kill would orphan workerd
const workerd = join(here, "node_modules/workerd/bin/workerd");
const app = (name) => readFile(join(here, "apps", name), "utf8");

const freePort = () =>
	new Promise((resolve) => {
		const s = createServer().listen(0, "127.0.0.1", () => {
			const { port } = s.address();
			s.close(() => resolve(port));
		});
	});

/** @param {string} socketPath the admin socket; holding it is the authority to install */
const makeAdmin = (socketPath) => ({
	install: (vat, src) =>
		new Promise((resolve, reject) => {
			const req = request({ socketPath, path: `/${vat}`, method: "PUT", agent: false }, (res) => {
				let body = "";
				res.on("data", (c) => (body += c));
				res.on("end", () => resolve(body.trim()));
			});
			req.on("error", reject);
			req.end(src);
		}),
});

/** @param {string} base the public origin */
const makePublic = (base) => ({
	get: async (vat) => (await fetch(`${base}/${vat}`)).text(),
	put: async (vat, src) => (await fetch(`${base}/${vat}`, { method: "PUT", body: src })).status,
});

/** Run workerd on `dir`'s state until `stop()`; resolves once the port answers. */
const startWorkerd = async (dir, port) => {
	await rm(join(dir, "admin.sock"), { force: true }); // left behind by a crash; bind() would fail
	const child = spawn(
		workerd,
		["serve", "--experimental", join(here, "config.capnp"),
			"-s", `http=127.0.0.1:${port}`, "-s", `admin=unix:${join(dir, "admin.sock")}`,
			"-d", `state=${join(dir, "state")}`],
		{ stdio: ["ignore", "ignore", "pipe"] },
	);
	let log = "";
	child.stderr.on("data", (c) => (log += c));
	const exited = new Promise((resolve) => child.on("exit", resolve));
	for (let i = 0; i < 100; i++) {
		try {
			await fetch(`http://127.0.0.1:${port}/`);
			// SIGKILL: a crash is the harder durability test
			return { stop: () => (child.kill("SIGKILL"), exited) };
		} catch {
			await new Promise((r) => setTimeout(r, 50));
		}
	}
	child.kill("SIGKILL");
	throw new Error(`workerd did not start: ${log}`);
};

let dir, port, server, admin, pub;

before(async () => {
	dir = await mkdtemp(join(tmpdir(), "toybox-"));
	await mkdir(join(dir, "state"));
	port = await freePort();
	server = await startWorkerd(dir, port);
	admin = makeAdmin(join(dir, "admin.sock"));
	pub = makePublic(`http://127.0.0.1:${port}`);
});

after(async () => {
	await server?.stop();
	await rm(dir, { recursive: true, force: true });
});

test("a vat with no code is 404", async () => {
	assert.equal(await pub.get("nobody"), "no code installed\n");
});

test("install, run, upgrade: the app's state carries over", async () => {
	assert.match(await admin.install("alice", await app("counter-v1.js")), /^[0-9a-f]{64}$/);
	assert.equal(await pub.get("alice"), "v1 count 1\n");
	assert.equal(await pub.get("alice"), "v1 count 2\n");
	await admin.install("alice", await app("counter-v2.js"));
	assert.equal(await pub.get("alice"), "v2 count 3\n");
});

test("vats don't share state", async () => {
	await admin.install("carol", await app("counter-v1.js"));
	assert.equal(await pub.get("carol"), "v1 count 1\n");
});

test("an app gets no fetch", async () => {
	await admin.install("bob", await app("try-fetch.js"));
	assert.match(await pub.get("bob"), /^fetch refused: This worker is not permitted to access the internet/);
});

test("the public port can't install code", async () => {
	assert.equal(await pub.put("mallory", "export class App {}"), 404);
	assert.equal(await pub.get("mallory"), "no code installed\n");
});

test("code and state survive a restart", async () => {
	await admin.install("dave", await app("counter-v1.js"));
	assert.equal(await pub.get("dave"), "v1 count 1\n");
	await server.stop();
	server = await startWorkerd(dir, port);
	assert.equal(await pub.get("dave"), "v1 count 2\n");
});