cloudflare--workers-sdk/packages/wrangler/e2e/remote-binding/start-worker-remote-bindings.test.ts

import { readFile, writeFile } from "node:fs/promises";
import { resolve } from "node:path";
import { setTimeout } from "node:timers/promises";
import { beforeAll, describe, it } from "vitest";
import { CLOUDFLARE_ACCOUNT_ID } from "../helpers/account-id";
import {
	importWrangler,
	WranglerE2ETestHelper,
} from "../helpers/e2e-wrangler-test";

const { unstable_startWorker: startWorker } = await importWrangler();

describe.skipIf(!CLOUDFLARE_ACCOUNT_ID)("startWorker - remote bindings", () => {
	const remoteWorkerName = "preserve-e2e-wrangler-remote-worker";
	const helper = new WranglerE2ETestHelper();

	beforeAll(async () => {
		await helper.seed(resolve(__dirname, "./workers"));
		await helper.ensureWorkerDeployed({
			entryPoint: "remote-worker.js",
			workerName: remoteWorkerName,
		});
	}, 60_000);

	it("allows connecting to a remote worker", async ({ expect }) => {
		await helper.seed({
			"wrangler.json": JSON.stringify({
				name: "remote-bindings-test",
				main: "simple-service-binding.js",
				compatibility_date: "2025-05-07",
				services: [
					{
						binding: "REMOTE_WORKER",
						service: remoteWorkerName,
						remote: true,
					},
				],
			}),
		});

		const worker = await startWorker({
			config: `${helper.tmpPath}/wrangler.json`,
			dev: {
				inspector: false,
				server: { port: 0 },
			},
		});

		await worker.ready;

		await expect(
			(await worker.fetch("http://example.com")).text()
		).resolves.toContain("REMOTE<WORKER>: Hello from a remote worker");

		await worker.dispose();
	});

	it("handles code changes during development", async ({ expect }) => {
		await helper.seed({
			"wrangler.json": JSON.stringify({
				name: "remote-bindings-test",
				main: "simple-service-binding.js",
				compatibility_date: "2025-05-07",
				services: [
					{
						binding: "REMOTE_WORKER",
						service: remoteWorkerName,
						remote: true,
					},
				],
			}),
		});

		const worker = await startWorker({
			config: `${helper.tmpPath}/wrangler.json`,
			dev: {
				inspector: false,
				server: { port: 0 },
			},
		});

		await worker.ready;

		await expect(
			(await worker.fetch("http://example.com")).text()
		).resolves.toContain("REMOTE<WORKER>: Hello from a remote worker");

		const indexContent = await readFile(
			`${helper.tmpPath}/simple-service-binding.js`,
			"utf8"
		);
		await writeFile(
			`${helper.tmpPath}/simple-service-binding.js`,
			indexContent.replace(
				"REMOTE<WORKER>:",
				"The remote worker responded with:"
			),
			"utf8"
		);

		await setTimeout(500);

		await expect(
			(await worker.fetch("http://example.com")).text()
		).resolves.toContain(
			"The remote worker responded with: Hello from a remote worker"
		);

		await writeFile(
			`${helper.tmpPath}/simple-service-binding.js`,
			indexContent,
			"utf8"
		);

		await setTimeout(500);

		await expect(
			(await worker.fetch("http://example.com")).text()
		).resolves.toContain("REMOTE<WORKER>: Hello from a remote worker");

		await worker.dispose();
	});
});

it("doesn't connect to remote bindings when `remote` is set to `false`", async ({
	expect,
}) => {
	const helper = new WranglerE2ETestHelper();
	await helper.seed(resolve(__dirname, "./workers"));
	await helper.seed({
		"wrangler.json": JSON.stringify({
			name: "remote-bindings-test",
			main: "ai.js",
			compatibility_date: "2025-05-07",
			ai: {
				binding: "AI",
				remote: true,
			},
		}),
	});

	await expect(async () => {
		const worker = await startWorker({
			config: `${helper.tmpPath}/wrangler.json`,
			dev: {
				inspector: false,
				server: { port: 0 },
				remote: false,
			},
		});

		await worker.ready;

		await worker.fetch("http://example.com");
	}).rejects.toThrowErrorMatchingInlineSnapshot(
		`[Error: Binding AI needs to be run remotely]`
	);
});