fix(C3): Use today's date for compat date when the latest workerd rel…

…ease date is in the future (#7891)

Fixes an issue where deployments would fail when there is a workerd
release on the same day due to workerd releases having a date in the
future because Workers does not allow using a compat date in the future.

.changeset/heavy-otters-cough.md

@@ -0,0 +1,7 @@
+---
+"create-cloudflare": patch
+---
+
+fix: Use today's date for compat date when the latest workerd release date is in the future
+
+Fixes an issue where deployments would fail when there is a workerd release on the same day due to workerd releases having a date in the future because Workers does not allow using a compat date in the future.

packages/create-cloudflare/src/helpers/__tests__/compatDate.test.ts

@@ -4,7 +4,7 @@ import {
 	getWorkerdCompatibilityDate,
 } from "helpers/compatDate";
 import { getGlobalDispatcher, MockAgent, setGlobalDispatcher } from "undici";
-import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
+import { afterEach, beforeEach, describe, expect, it, test, vi } from "vitest";
 import { createTestContext } from "../../__tests__/helpers";
 import { mockSpinner, mockWorkersTypesDirectory } from "./mocks";
 
@@ -29,6 +29,7 @@ describe("Compatibility Date Helpers", () => {
 	afterEach(() => {
 		agent.assertNoPendingInterceptors();
 		setGlobalDispatcher(originalDispatcher);
+		vi.useRealTimers();
 	});
 
 	const mockRegistryFetch = (latest: string) => {
@@ -62,7 +63,7 @@ describe("Compatibility Date Helpers", () => {
 
 			const date = await getWorkerdCompatibilityDate();
 
-			const fallbackDate = "2023-05-18";
+			const fallbackDate = "2024-11-11";
 			expect(date).toBe(fallbackDate);
 			expect(spinner.start).toHaveBeenCalled();
 			expect(spinner.stop).toHaveBeenCalledWith(
@@ -78,13 +79,29 @@ describe("Compatibility Date Helpers", () => {
 
 			const date = await getWorkerdCompatibilityDate();
 
-			const fallbackDate = "2023-05-18";
+			const fallbackDate = "2024-11-11";
 			expect(date).toBe(fallbackDate);
 			expect(spinner.start).toHaveBeenCalled();
 			expect(spinner.stop).toHaveBeenCalledWith(
 				expect.stringContaining(fallbackDate),
 			);
 		});
+
+		it("should use today's date if workerd's release is in the future", async () => {
+			vi.setSystemTime("2025-01-09T23:59:59.999Z");
+			console.log(new Date().toISOString());
+			mockRegistryFetch("2.20250110.5");
+
+			const date = await getWorkerdCompatibilityDate();
+
+			// should get back today because deploy will fail with a future date
+			const expectedDate = "2025-01-09";
+			expect(date).toBe(expectedDate);
+			expect(spinner.start).toHaveBeenCalled();
+			expect(spinner.stop).toHaveBeenCalledWith(
+				expect.stringContaining(expectedDate),
+			);
+		});
 	});
 
 	test("compatDateFlag", async () => {

packages/create-cloudflare/src/helpers/compatDate.ts

@@ -26,16 +26,28 @@ export async function getWorkerdCompatibilityDate() {
 		// The format of the workerd version is `major.yyyymmdd.patch`.
 		const match = latestWorkerdVersion.match(/\d+\.(\d{4})(\d{2})(\d{2})\.\d+/);
 
+		// workerd releases often have a date for the following day.
+		// Unfortunately, Workers deployments will fail if they specify
+		// a compatibility date in the future. This means that most
+		// who create a new project on the same day as a workerd
+		// release will have their deployments fail until they
+		// manually adjust the compatibility date.
+		//
+		// To work around this, we must manually ensure that the compat date
+		// is not on a future UTC day when there was a recent workerd release.
 		if (match) {
 			const [, year, month, date] = match;
-			const compatDate = `${year}-${month}-${date}`;
-
-			s.stop(`${brandColor("compatibility date")} ${dim(compatDate)}`);
-			return compatDate;
+			let compatDate = new Date(`${year}-${month}-${date}`);
+			if (compatDate.getTime() > Date.now()) {
+				compatDate = new Date(Date.now());
+			}
+			const compatDateString = compatDate.toISOString().slice(0, 10);
+			s.stop(`${brandColor("compatibility date")} ${dim(compatDateString)}`);
+			return compatDateString;
 		}
 	} catch {}
 
-	const fallbackDate = "2023-05-18";
+	const fallbackDate = "2024-11-11";
 
 	s.stop(
 		`${brandColor("compatibility date")} ${dim(