add e2e test

packages/wrangler/e2e/dev.test.ts

@@ -47,7 +47,7 @@ describe("basic dev tests", () => {
 					name = "${workerName}"
 					main = "src/index.ts"
 					compatibility_date = "2023-01-01"
-					
+
 					[vars]
 					KEY = "value"
 			`,
@@ -101,7 +101,7 @@ describe("basic dev tests", () => {
 						name = "${workerName}"
 						main = "src/index.ts"
 						compatibility_date = "2023-01-01"
-						
+
 						[vars]
 						KEY = "updated"
 				`,
@@ -117,6 +117,57 @@ describe("basic dev tests", () => {
 		});
 	});
 
+	it("can recover from syntax error during dev session (local)", async () => {
+		await runDevSession(workerPath, "", async (port) => {
+			const { text } = await retry(
+				(s) => s.status !== 200,
+				async () => {
+					const r = await fetch(`http://127.0.0.1:${port}`);
+					return { text: await r.text(), status: r.status };
+				}
+			);
+			expect(text).toMatchInlineSnapshot('"Hello World!"');
+
+			await seed(workerPath, {
+				"src/index.ts": dedent`
+						export default {
+							fetch(request, env) {
+								return new Response("Updated Worker!")
+								} // <= added syntax error
+							}
+						}`,
+			});
+
+			// Output during error state is indeterminate.
+			// const { text: text2 } = await retry(
+			// 	(s) => s.status !== 200 || s.text === "Hello World!",
+			// 	async () => {
+			// 		const r = await fetch(`http://127.0.0.1:${port}`);
+			// 		return { text: await r.text(), status: r.status };
+			// 	}
+			// );
+			// expect(text2).toMatchInlineSnapshot('"Hello World!"');
+
+			await seed(workerPath, {
+				"src/index.ts": dedent`
+						export default {
+							fetch(request, env) {
+								return new Response("Updated Worker!")
+							}
+						}`,
+			});
+
+			const { text: text3 } = await retry(
+				(s) => s.status !== 200 || s.text === "Hello World!",
+				async () => {
+					const r = await fetch(`http://127.0.0.1:${port}`);
+					return { text: await r.text(), status: r.status };
+				}
+			);
+			expect(text3).toMatchInlineSnapshot('"Updated Worker!"');
+		});
+	});
+
 	it("can modify worker during dev session (remote)", async () => {
 		await runDevSession(workerPath, "--remote --ip 127.0.0.1", async (port) => {
 			const { text } = await retry(