Added helper for parsing and validating dates in yyyy-mm-dd format

Author: oskardudycz

src/packages/emmett/src/validation/dates.ts

@@ -0,0 +1,34 @@
+import { ValidationError } from '../errors';
+
+export const formatDateToUtcYYYYMMDD = (date: Date) => {
+  // Use the 'en-CA' locale which formats as 'yyyy-mm-dd'
+  const formatter = new Intl.DateTimeFormat('en-CA', {
+    timeZone: 'UTC',
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+  });
+
+  // Format the date
+  return formatter.format(date);
+};
+
+// Function to validate 'yyyy-mm-dd' format
+export const isValidYYYYMMDD = (dateString: string) => {
+  const regex = /^\d{4}-\d{2}-\d{2}$/;
+  return regex.test(dateString);
+};
+
+export const parseDateFromUtcYYYYMMDD = (dateString: string) => {
+  const date = new Date(dateString + 'T00:00:00Z');
+
+  if (!isValidYYYYMMDD(dateString)) {
+    throw new ValidationError('Invalid date format, must be yyyy-mm-dd');
+  }
+
+  if (isNaN(date.getTime())) {
+    throw new ValidationError('Invalid date format');
+  }
+
+  return date;
+};

src/packages/emmett/src/validation/index.ts

@@ -33,3 +33,5 @@ export const assertUnsignedBigInt = (value: string): bigint => {
   }
   return number;
 };
+
+export * from './dates';