Revert "Revert "startDevWorker - Milestone 1" (#4171)"

This reverts commit 88f15f6.

fixtures/dev-env/package.json

@@ -16,7 +16,7 @@
 		"@types/ws": "^8.5.7",
 		"@cloudflare/workers-tsconfig": "workspace:^",
 		"get-port": "^7.0.0",
-		"miniflare": "3.20231025.1",
+		"miniflare": "3.20231002.1",
 		"undici": "^5.23.0",
 		"wrangler": "workspace:*",
 		"ws": "^8.14.2"

fixtures/dev-env/tests/index.test.ts

@@ -18,20 +18,18 @@ const fakeBundle = {} as EsbuildBundle;
 
 let devEnv: DevEnv;
 let mf: Miniflare | undefined;
-let res: MiniflareResponse | undici.Response;
+let res: MiniflareResponse | undici.Response | undefined;
 let ws: WebSocket | undefined;
-let fireAndForgetPromises: Promise<any>[] = [];
 
 type OptionalKeys<T, K extends keyof T> = Omit<T, K> & Partial<Pick<T, K>>;
 
 beforeEach(() => {
 	devEnv = new DevEnv();
 	mf = undefined;
-	res = undefined as any;
+	res = undefined;
 	ws = undefined;
 });
 afterEach(async () => {
-	await Promise.allSettled(fireAndForgetPromises);
 	await devEnv?.teardown();
 	await mf?.dispose();
 	await ws?.close();
@@ -52,7 +50,7 @@ async function fakeStartUserWorker(options: {
 	};
 	const mfOpts: MiniflareOptions = Object.assign(
 		{
-			port: undefined,
+			port: 0,
 			inspectorPort: 0,
 			modules: true,
 			compatibilityDate: "2023-08-01",
@@ -69,11 +67,10 @@ async function fakeStartUserWorker(options: {
 	fakeReloadStart(config);
 
 	const worker = devEnv.startWorker(config);
-	const { proxyWorker } = await devEnv.proxy.ready.promise;
+	const { proxyWorker, inspectorProxyWorker } = await devEnv.proxy.ready
+		.promise;
 	const proxyWorkerUrl = await proxyWorker.ready;
-	const inspectorProxyWorkerUrl = await proxyWorker.unsafeGetDirectURL(
-		"InspectorProxyWorker"
-	);
+	const inspectorProxyWorkerUrl = await inspectorProxyWorker.ready;
 
 	mf = new Miniflare(mfOpts);
 
@@ -138,8 +135,7 @@ function fireAndForgetFakeUserWorkerChanges(
 	...args: Parameters<typeof fakeUserWorkerChanges>
 ) {
 	// fire and forget the reload -- this let's us test request buffering
-	const promise = fakeUserWorkerChanges(...args);
-	fireAndForgetPromises.push(promise);
+	void fakeUserWorkerChanges(...args);
 }
 
 function fakeConfigUpdate(config: StartDevWorkerOptions) {

packages/wrangler/package.json

@@ -60,7 +60,7 @@
 		"emit-types": "tsc -p tsconfig.emit.json && node -r esbuild-register scripts/emit-types.ts",
 		"prepublishOnly": "SOURCEMAPS=false npm run build",
 		"start": "pnpm run bundle && cross-env NODE_OPTIONS=--enable-source-maps ./bin/wrangler.js",
-		"test": "pnpm run assert-git-version && jest",
+		"test": "pnpm run assert-git-version && jest --runInBand",
 		"test:ci": "pnpm run test --coverage",
 		"test:debug": "pnpm run test --silent=false --verbose=true",
 		"test:e2e": "vitest --test-timeout 240000 --single-thread --dir ./e2e --retry 2 run",

packages/wrangler/src/api/startDevWorker/DevEnv.ts

@@ -1,5 +1,5 @@
-import assert from "node:assert";
 import { EventEmitter } from "node:events";
+import { fetch, Request, type RequestInit } from "miniflare";
 import { logger } from "../../logger";
 import { BundlerController } from "./BundlerController";
 import { ConfigController } from "./ConfigController";
@@ -47,14 +47,8 @@ export class DevEnv extends EventEmitter {
 			controller.on("error", (event) => this.emitErrorEvent(event))
 		);
 
-		this.on("error", (event: ErrorEvent) => {
-			// TODO: when we're are comfortable with StartDevWorker/DevEnv stability,
-			//       we can remove this handler and let the user handle the unknowable errors
-			//       or let the process crash. For now, log them to stderr
-			//       so we can identify knowable vs unknowable error candidates
-
-			logger.error(`Error in ${event.source}: ${event.reason}\n`, event.cause);
-			logger.debug("=> Error contextual data:", event.data);
+		this.on("error", (event) => {
+			logger.error(event);
 		});
 
 		config.on("configUpdate", (event) => {
@@ -105,48 +99,8 @@ export class DevEnv extends EventEmitter {
 		]);
 	}
 
-	emitErrorEvent(ev: ErrorEvent) {
-		if (
-			ev.source === "ProxyController" &&
-			ev.reason === "Failed to start ProxyWorker or InspectorProxyWorker"
-		) {
-			assert(ev.data.config); // we must already have a `config` if we've already tried (and failed) to instantiate the ProxyWorker(s)
-
-			const { config } = ev.data;
-			const port = config.dev?.server?.port;
-			const inspectorPort = config.dev?.inspector?.port;
-			const randomPorts = [0, undefined];
-
-			// console.log({ port, inspectorPort, ev });
-			if (!randomPorts.includes(port) || !randomPorts.includes(inspectorPort)) {
-				// emit the event here while the ConfigController is unimplemented
-				// this will cause the ProxyController to try reinstantiating the ProxyWorker(s)
-				// TODO: change this to `this.config.updateOptions({ dev: { server: { port: 0 }, inspector: { port: 0 } } });` when the ConfigController is implemented
-				this.config.emitConfigUpdateEvent({
-					type: "configUpdate",
-					config: {
-						...config,
-						dev: {
-							...config.dev,
-							server: { ...config.dev?.server, port: 0 }, // override port
-							inspector: { ...config.dev?.inspector, port: 0 }, // override port
-						},
-					},
-				});
-			}
-		} else if (
-			ev.source === "ProxyController" &&
-			(ev.reason.startsWith("Failed to send message to") ||
-				ev.reason.startsWith("Could not connect to InspectorProxyWorker"))
-		) {
-			logger.debug(`Error in ${ev.source}: ${ev.reason}\n`, ev.cause);
-			logger.debug("=> Error contextual data:", ev.data);
-		}
-		// if other knowable + recoverable errors occur, handle them here
-		else {
-			// otherwise, re-emit the unknowable errors to the top-level
-			this.emit("error", ev);
-		}
+	emitErrorEvent(data: ErrorEvent) {
+		this.emit("error", data);
 	}
 }
 
@@ -166,9 +120,18 @@ export function createWorkerObject(devEnv: DevEnv): DevWorker {
 		},
 		async fetch(...args) {
 			const { proxyWorker } = await devEnv.proxy.ready.promise;
-			await devEnv.proxy.runtimeMessageMutex.drained();
-
-			return proxyWorker.dispatchFetch(...args);
+			// return proxyWorker.dispatchFetch(...args);
+			// ^ bug: Miniflare#dispatchFetch uses one HTTP/1.1 connection, preventing parallel requests (pause/play requests + buffered eyeball requests)
+			// workaround: use undici.fetch
+			const proxyWorkerUrl = await proxyWorker.ready;
+			const req = new Request(...args);
+			const url = new URL(req.url);
+			url.protocol = proxyWorkerUrl.protocol;
+			url.hostname = proxyWorkerUrl.hostname;
+			url.port = proxyWorkerUrl.port;
+			// /workaround
+
+			return fetch(url, req as RequestInit);
 		},
 		async queue(..._args) {
 			// const { worker } = await devEnv.proxy.ready;