stop vitest pool workers breaking when containers are present (#10162)

* add vitest fixture

* changeset

* add override to disable containers in vitest

* fix pnpm lock

* fixup

Author: emily-shen

.changeset/evil-loops-eat.md

@@ -0,0 +1,7 @@
+---
+"@cloudflare/vitest-pool-workers": patch
+---
+
+fix: stop containers breaking vitest-pool-workers
+
+Testing interactions with containers is still currently unsupported.

fixtures/vitest-pool-workers-examples/container-app/Dockerfile

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+FROM node:22-alpine
+
+WORKDIR /usr/src/app
+RUN echo '{"name": "simple-node-app", "version": "1.0.0", "dependencies": {"ws": "^8.0.0"}}' > package.json
+RUN npm install
+
+COPY ./container/simple-node-app.js app.js
+EXPOSE 8787
+CMD ["node", "app.js"]

fixtures/vitest-pool-workers-examples/container-app/README.md

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+# Apps with no-op containers
+
+Currently, `vitest-pool-workers` does not support testing containers yet. It should still let you test your application as long as you do not test with any code paths that interact with containers.

fixtures/vitest-pool-workers-examples/container-app/container/simple-node-app.js

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+const { createServer } = require("http");
+
+// Create HTTP server
+const server = createServer(function (req, res) {
+	res.writeHead(200, { "Content-Type": "text/plain" });
+	res.write("Hello World! Have an env var! " + process.env.MESSAGE);
+	res.end();
+});
+
+server.listen(8787, function () {
+	console.log("Server listening on port 8080");
+});

fixtures/vitest-pool-workers-examples/container-app/src/index.ts

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+import { Container, getContainer, getRandom } from "@cloudflare/containers"; // in a real Worker
+
+export class MyContainer extends Container {
+	defaultPort = 8787; // The default port for the container to listen on
+	sleepAfter = "3m"; // Sleep the container if no requests are made in this timeframe
+
+	envVars = {
+		MESSAGE: "I was passed in via the container class!",
+	};
+
+	override onStart() {
+		console.log("Container successfully started");
+	}
+
+	override onStop() {
+		console.log("Container successfully shut down");
+	}
+
+	override onError(error: unknown) {
+		console.log("Container error:", error);
+	}
+}
+
+export default {
+	async fetch(
+		request: Request,
+		env: { MY_CONTAINER: DurableObjectNamespace<MyContainer> }
+	): Promise<Response> {
+		const pathname = new URL(request.url).pathname;
+		// If you want to route requests to a specific container,
+		// pass a unique container identifier to .get()
+
+		if (pathname.startsWith("/container")) {
+			const containerInstance = getContainer(env.MY_CONTAINER, pathname);
+			return containerInstance.fetch(request);
+		}
+
+		if (pathname.startsWith("/error")) {
+			const containerInstance = getContainer(env.MY_CONTAINER, "error-test");
+			return containerInstance.fetch(request);
+		}
+
+		if (pathname.startsWith("/lb")) {
+			const containerInstance = await getRandom(env.MY_CONTAINER, 3);
+			return containerInstance.fetch(request);
+		}
+
+		if (pathname.startsWith("/singleton")) {
+			// getContainer will return a specific instance if no second argument is provided
+			return getContainer(env.MY_CONTAINER).fetch(request);
+		}
+
+		return new Response(
+			"Call /container to start a container with a 10s timeout.\nCall /error to start a container that errors\nCall /lb to test load balancing"
+		);
+	},
+};

fixtures/vitest-pool-workers-examples/container-app/src/tsconfig.json

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+{
+	"extends": "../../tsconfig.workerd.json",
+	"include": ["./**/*.ts"]
+}

fixtures/vitest-pool-workers-examples/container-app/test/container.test.ts

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+import { env, runDurableObjectAlarm, SELF } from "cloudflare:test";
+import { expect, it, vi } from "vitest";
+
+it("dispatches fetch event", { timeout: 10_000 }, async () => {
+	// requests to code paths that do not interact with a container should work fine
+	const res = await SELF.fetch("http://example.com/");
+	expect(await res.text()).toMatchInlineSnapshot(`
+		"Call /container to start a container with a 10s timeout.
+		Call /error to start a container that errors
+		Call /lb to test load balancing"
+	`);
+	// however if you attempt to start a container, you should expect an error
+	await expect(() =>
+		SELF.fetch("http://example.com/container/hello")
+	).rejects.toThrow();
+});

fixtures/vitest-pool-workers-examples/container-app/test/container.unit.test.ts

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+import { env } from "cloudflare:test";
+import { expect, it } from "vitest";
+
+it("dispatches fetch event", { timeout: 10000 }, async () => {
+	const id = env.MY_CONTAINER.idFromName("helloagain");
+	const stub = env.MY_CONTAINER.get(id);
+	// the DO constructor will now throw
+	await expect(() => stub.fetch("http://example.com/")).rejects.toThrow();
+});

fixtures/vitest-pool-workers-examples/container-app/test/env.d.ts

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+declare module "cloudflare:test" {
+	// Controls the type of `import("cloudflare:test").env`
+	interface ProvidedEnv extends Env {
+		MY_CONTAINER: DurableObjectNamespace<MyContainer>;
+	}
+}

fixtures/vitest-pool-workers-examples/container-app/test/tsconfig.json

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+{
+	"extends": "../../tsconfig.workerd-test.json",
+	"include": ["./**/*.ts"]
+}