fix: PR feedback 2

packages/wrangler/e2e/dev.test.ts

@@ -882,6 +882,57 @@ describe("custom builds", () => {
 });
 
 describe("watch mode", () => {
+	describe.each([{ cmd: "wrangler dev" }, { cmd: "wrangler dev --x-dev-env" }])(
+		"Workers watch mode: $cmd",
+		({ cmd }) => {
+			it(`supports modifying the Worker script during dev session`, async () => {
+				const helper = new WranglerE2ETestHelper();
+				await helper.seed({
+					"wrangler.toml": dedent`
+								name = "${workerName}"
+								main = "src/workerA.ts"
+								compatibility_date = "2023-01-01"
+						`,
+					"src/workerA.ts": dedent`
+						export default {
+							fetch(request) {
+								return new Response("Hello from user Worker A!")
+							}
+						}`,
+				});
+
+				const worker = helper.runLongLived(cmd);
+				const { url } = await worker.waitForReady();
+
+				let text = await fetchText(url);
+				expect(text).toBe("Hello from user Worker A!");
+
+				await helper.seed({
+					"wrangler.toml": dedent`
+								name = "${workerName}"
+								main = "src/workerB.ts"
+								compatibility_date = "2023-01-01"
+						`,
+					"src/workerB.ts": dedent`
+						export default {
+							fetch(request) {
+								return new Response("Hello from user Worker B!")
+							}
+						}`,
+				});
+
+				await worker.waitForReload();
+				text = await retry(
+					(s) => s != "Hello from user Worker B!",
+					async () => {
+						return await fetchText(url);
+					}
+				);
+				expect(text).toBe("Hello from user Worker B!");
+			});
+		}
+	);
+
 	describe.each([{ cmd: "wrangler dev" }, { cmd: "wrangler dev --x-dev-env" }])(
 		"Workers + Assets watch mode: $cmd",
 		({ cmd }) => {
@@ -1088,7 +1139,145 @@ describe("watch mode", () => {
 				);
 			});
 
-			it(`supports switching from assets-only to Workers with assets during the current dev session`, async () => {
+			it(`supports switching from Workers without assets to assets-only Workers during the current dev session`, async () => {
+				const helper = new WranglerE2ETestHelper();
+				await helper.seed({
+					"wrangler.toml": dedent`
+							name = "${workerName}"
+							main = "src/index.ts"
+							compatibility_date = "2023-01-01"
+					`,
+					"src/index.ts": dedent`
+						export default {
+							fetch(request) {
+								return new Response("Hello from user Worker!")
+							}
+						}`,
+				});
+
+				const worker = helper.runLongLived(cmd);
+				const { url } = await worker.waitForReady();
+
+				let response = await fetch(url);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+
+				response = await fetch(`${url}/hey`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+
+				response = await fetch(`${url}/index.html`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+
+				await helper.seed({
+					"wrangler.toml": dedent`
+								name = "${workerName}"
+								compatibility_date = "2023-01-01"
+
+								[experimental_assets]
+								directory = "./public"
+						`,
+					"public/index.html": dedent`
+								<h1>Hello Workers + Assets</h1>`,
+				});
+
+				await worker.waitForReload();
+
+				// verify response from Asset Worker
+				const { status, text } = await retry(
+					(s) => s.text !== "<h1>Hello Workers + Assets</h1>",
+					async () => {
+						const fetchResponse = await fetch(url);
+						return {
+							status: fetchResponse.status,
+							text: await fetchResponse.text(),
+						};
+					}
+				);
+				expect(status).toBe(200);
+				expect(text).toBe("<h1>Hello Workers + Assets</h1>");
+
+				response = await fetch(`${url}/index.html`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("<h1>Hello Workers + Assets</h1>");
+
+				// verify we no longer get a response from the User Worker
+				response = await fetch(`${url}/hey`);
+				expect(response.status).toBe(404);
+			});
+
+			it(`supports switching from Workers without assets to Workers with assets during the current dev session`, async () => {
+				const helper = new WranglerE2ETestHelper();
+				await helper.seed({
+					"wrangler.toml": dedent`
+							name = "${workerName}"
+							main = "src/index.ts"
+							compatibility_date = "2023-01-01"
+					`,
+					"src/index.ts": dedent`
+						export default {
+							fetch(request) {
+								return new Response("Hello from user Worker!")
+							}
+						}`,
+				});
+
+				const worker = helper.runLongLived(cmd);
+				const { url } = await worker.waitForReady();
+
+				let response = await fetch(url);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+
+				response = await fetch(`${url}/hey`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+
+				response = await fetch(`${url}/index.html`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+
+				await helper.seed({
+					"wrangler.toml": dedent`
+								name = "${workerName}"
+								main = "src/index.ts"
+								compatibility_date = "2023-01-01"
+
+								[experimental_assets]
+								directory = "./public"
+						`,
+					"public/index.html": dedent`
+								<h1>Hello Workers + Assets</h1>`,
+				});
+
+				await worker.waitForReload();
+
+				// verify response from Asset Worker
+				const { status, text } = await retry(
+					(s) => s.text !== "<h1>Hello Workers + Assets</h1>",
+					async () => {
+						const fetchResponse = await fetch(url);
+						return {
+							status: fetchResponse.status,
+							text: await fetchResponse.text(),
+						};
+					}
+				);
+				expect(status).toBe(200);
+				expect(text).toBe("<h1>Hello Workers + Assets</h1>");
+
+				response = await fetch(`${url}/index.html`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("<h1>Hello Workers + Assets</h1>");
+
+				// verify response from the User Worker
+				response = await fetch(`${url}/hey`);
+				expect(response.status).toBe(200);
+				expect(await response.text()).toBe("Hello from user Worker!");
+			});
+
+			it(`supports switching from assets-only Workers to Workers with assets during the current dev session`, async () => {
 				const helper = new WranglerE2ETestHelper();
 				await helper.seed({
 					"wrangler.toml": dedent`
@@ -1144,7 +1333,7 @@ describe("watch mode", () => {
 				expect(await response.text()).toBe("Hello from user Worker!");
 			});
 
-			it(`supports switching from Workers with assets to assets-only during the current dev session`, async () => {
+			it(`supports switching from Workers with assets to assets-only Workers during the current dev session`, async () => {
 				const helper = new WranglerE2ETestHelper();
 				await helper.seed({
 					"wrangler.toml": dedent`
@@ -1289,7 +1478,7 @@ describe("watch mode", () => {
 			expect(response.status).toBe(404);
 		});
 
-		it(`supports switching from assets-only to Workers with assets during the current dev session`, async () => {
+		it(`supports switching from assets-only Workers to Workers with assets during the current dev session`, async () => {
 			const helper = new WranglerE2ETestHelper();
 			await helper.seed({
 				"wrangler.toml": dedent`

packages/wrangler/src/dev.tsx

@@ -845,32 +845,22 @@ export async function startDev(args: StartDevOptions) {
 
 					logger.log(`${path.basename(config.configPath)} changed...`);
 
-					/*
-					 * If this is a Worker with assets, we want to enable switching
-					 * from assets only Worker to Worker with assets and vice versa
-					 * during local development. For that, we need to watch for changes
-					 * in the `wrangler.toml` file, specifically the `main` configuration
-					 * key, and re-asses the entry point every time.
-					 */
-					if (experimentalAssetsOptions?.directory) {
-						entry = await getEntry(
-							{
-								legacyAssets: args.legacyAssets,
-								script: args.script,
-								moduleRoot: args.moduleRoot,
-								experimentalAssets: args.experimentalAssets,
-							},
-							config,
-							"dev"
-						);
+					// ensure we reflect config changes in the `main` entry point
+					entry = await getEntry(
+						{
+							legacyAssets: args.legacyAssets,
+							script: args.script,
+							moduleRoot: args.moduleRoot,
+							experimentalAssets: args.experimentalAssets,
+						},
+						config,
+						"dev"
+					);
 
-						// this gets passed into the Dev React element, so ensure we don't
-						// block scope this var
-						experimentalAssetsOptions = processExperimentalAssetsArg(
-							args,
-							config
-						);
-					}
+					experimentalAssetsOptions = processExperimentalAssetsArg(
+						args,
+						config
+					);
 
 					/*
 					 * Handle experimental assets watching on config file changes

packages/wrangler/src/experimental-assets.ts

@@ -328,45 +328,46 @@ export function processExperimentalAssetsArg(
 	const experimentalAssets = args.experimentalAssets
 		? { directory: args.experimentalAssets }
 		: config.experimental_assets;
-	let experimentalAssetsOptions: ExperimentalAssetsOptions | undefined;
-	if (experimentalAssets) {
-		const experimentalAssetsBasePath = getExperimentalAssetsBasePath(
-			config,
-			args.experimentalAssets
-		);
-		const resolvedExperimentalAssetsPath = path.resolve(
-			experimentalAssetsBasePath,
-			experimentalAssets.directory
-		);
 
-		if (!existsSync(resolvedExperimentalAssetsPath)) {
-			const sourceOfTruthMessage = args.experimentalAssets
-				? '"--experimental-assets" command line argument'
-				: '"experimental_assets.directory" field in your configuration file';
+	if (!experimentalAssets) {
+		return;
+	}
 
-			throw new UserError(
-				`The directory specified by the ${sourceOfTruthMessage} does not exist:\n` +
-					`${resolvedExperimentalAssetsPath}`
-			);
-		}
+	const experimentalAssetsBasePath = getExperimentalAssetsBasePath(
+		config,
+		args.experimentalAssets
+	);
+	const resolvedExperimentalAssetsPath = path.resolve(
+		experimentalAssetsBasePath,
+		experimentalAssets.directory
+	);
 
-		experimentalAssets.directory = resolvedExperimentalAssetsPath;
-		const routingConfig = {
-			has_user_worker: Boolean(args.script || config.main),
-		};
-		// defaults are set in asset worker
-		const assetConfig = {
-			html_handling: config.experimental_assets?.html_handling,
-			not_found_handling: config.experimental_assets?.not_found_handling,
-		};
-		experimentalAssetsOptions = {
-			...experimentalAssets,
-			routingConfig,
-			assetConfig,
-		};
+	if (!existsSync(resolvedExperimentalAssetsPath)) {
+		const sourceOfTruthMessage = args.experimentalAssets
+			? '"--experimental-assets" command line argument'
+			: '"experimental_assets.directory" field in your configuration file';
+
+		throw new UserError(
+			`The directory specified by the ${sourceOfTruthMessage} does not exist:\n` +
+				`${resolvedExperimentalAssetsPath}`
+		);
 	}
 
-	return experimentalAssetsOptions;
+	experimentalAssets.directory = resolvedExperimentalAssetsPath;
+	const routingConfig = {
+		has_user_worker: Boolean(args.script || config.main),
+	};
+	// defaults are set in asset worker
+	const assetConfig = {
+		html_handling: config.experimental_assets?.html_handling,
+		not_found_handling: config.experimental_assets?.not_found_handling,
+	};
+
+	return {
+		...experimentalAssets,
+		routingConfig,
+		assetConfig,
+	};
 }
 
 /**