Fixes #4844 with more defensive date parsing

frontend/src/locale/Utils.test.tsx

@@ -0,0 +1,74 @@
+import { formatDateTime } from "src/locale";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+
+describe("DateFormatter", () => {
+	// Keep a reference to the real Intl to restore later
+	const RealIntl = global.Intl;
+	const desiredTimeZone = "Europe/London";
+	const desiredLocale = "en-GB";
+
+	beforeAll(() => {
+		// Ensure Node-based libs using TZ behave deterministically
+		try {
+			process.env.TZ = desiredTimeZone;
+		} catch {
+			// ignore if not available
+		}
+
+		// Mock Intl.DateTimeFormat so formatting is stable regardless of host
+		const MockedDateTimeFormat = class extends RealIntl.DateTimeFormat {
+			constructor(_locales?: string | string[], options?: Intl.DateTimeFormatOptions) {
+				super(desiredLocale, {
+					...options,
+					timeZone: desiredTimeZone,
+				});
+			}
+		} as unknown as typeof Intl.DateTimeFormat;
+
+		global.Intl = {
+			...RealIntl,
+			DateTimeFormat: MockedDateTimeFormat,
+		};
+	});
+
+	afterAll(() => {
+		// Restore original Intl after tests
+		global.Intl = RealIntl;
+	});
+
+	it("format date from iso date", () => {
+		const value = "2024-01-01T00:00:00.000Z";
+		const text = formatDateTime(value);
+		expect(text).toBe("Monday, 01/01/2024, 12:00:00 am");
+	});
+
+	it("format date from unix timestamp number", () => {
+		const value = 1762476112;
+		const text = formatDateTime(value);
+		expect(text).toBe("Friday, 07/11/2025, 12:41:52 am");
+	});
+
+	it("format date from unix timestamp string", () => {
+		const value = "1762476112";
+		const text = formatDateTime(value);
+		expect(text).toBe("Friday, 07/11/2025, 12:41:52 am");
+	});
+
+	it("catch bad format from string", () => {
+		const value = "this is not a good date";
+		const text = formatDateTime(value);
+		expect(text).toBe("this is not a good date");
+	});
+
+	it("catch bad format from number", () => {
+		const value = -100;
+		const text = formatDateTime(value);
+		expect(text).toBe("-100");
+	});
+
+	it("catch bad format from number as string", () => {
+		const value = "-100";
+		const text = formatDateTime(value);
+		expect(text).toBe("-100");
+	});
+});

frontend/src/locale/Utils.ts

@@ -11,13 +11,19 @@ const isUnixTimestamp = (value: unknown): boolean => {
 	return false;
 };
 
-const DateTimeFormat = (value: string | number): string => {
-	if (typeof value !== "number" && typeof value !== "string") return `${value}`;
-
+const parseDate = (value: string | number): Date | null => {
+	if (typeof value !== "number" && typeof value !== "string") return null;
+	try {
+		return isUnixTimestamp(value) ? fromUnixTime(+value) : parseISO(`${value}`);
+	} catch {
+		return null;
+	}
+};
+
+const formatDateTime = (value: string | number): string => {
+	const d = parseDate(value);
+	if (!d) return `${value}`;
 	try {
-		const d = isUnixTimestamp(value)
-			? fromUnixTime(+value)
-			: parseISO(`${value}`);
 		return intlFormat(d, {
 			weekday: "long",
 			year: "numeric",
@@ -33,4 +39,4 @@ const DateTimeFormat = (value: string | number): string => {
 	}
 };
 
-export { DateTimeFormat };
+export { formatDateTime, parseDate, isUnixTimestamp };

frontend/src/locale/index.ts

@@ -1,2 +1,2 @@
-export * from "./DateTimeFormat";
 export * from "./IntlProvider";
+export * from "./Utils";