Changed error message

Author: stevebux

lambdas/api-handler/src/contracts/errors.ts

@@ -35,7 +35,8 @@ export enum ApiErrorDetail {
   InvalidRequestLimitNotANumber = 'The limit parameter is not a number',
   InvalidRequestLimitNotInRange = 'The limit parameter must be a positive number not greater than %s',
   InvalidRequestLimitOnly = "Only 'limit' query parameter is supported",
-  InvalidRequestNoRequestId = 'The request does not contain a request id'
+  InvalidRequestNoRequestId = 'The request does not contain a request id',
+  InvalidRequestTimestamp = 'Timestamps should be UTC date/times in ISO8601 format, with a Z suffix'
 }
 
 export function buildApiError(params: {

lambdas/api-handler/src/handlers/post-mi.ts

@@ -48,7 +48,7 @@ export const postMi: APIGatewayProxyHandler = async (event) => {
 
     const date = new Date(timestamp);
     if (Number.isNaN(date.valueOf()) || date.toISOString() !== timestamp) {
-      throw new ValidationError('%s is not a valid ISO8601 instant', {args: [timestamp]});
+      throw new ValidationError(ApiErrorDetail.InvalidRequestTimestamp);
     }
   }
 };