Merge remote-tracking branch 'origin/master'

backend/date.test.ts

@@ -6,11 +6,12 @@
 
 import { describe, expect, test } from "@jest/globals";
 import { formatSGT } from "./date";
+import { TZDate } from "@date-fns/tz";
 
 describe("CongestionSvc", () => {
   test("formatSGT()", async () => {
     // month is zero indexed: 3 -> April
-    expect(formatSGT(new Date("2024-04-01T00:00:00.000+0000"))).toStrictEqual(
+    expect(formatSGT(new TZDate("2024-04-01T00:00:00.000+0000"))).toStrictEqual(
       "2024-04-01T08:00:00.000+0800",
     );
   });

backend/date.ts

@@ -5,7 +5,9 @@
  */
 
 import { TZDate } from "@date-fns/tz";
-import { formatDate } from "date-fns";
+import { eachDayOfInterval, eachHourOfInterval, formatDate } from "date-fns";
+
+export type DateInterval = "day" | "hour";
 
 /**
  * Formats a given date to Singapore Standard Time (SGT) in ISO 8601 format.
@@ -14,18 +16,41 @@ import { formatDate } from "date-fns";
  * then adjusts it to Singapore Standard Time (SGT) and formats the date
  * to the iso 8601 format with millisecond precision.
  *
- * @param {Date} date - The date to format in SGT.
- * @returns {string} The formatted date string in SGT, ISO 8601 format.
+ * @param date - The date to format in SGT.
+ * @returns The formatted date string in SGT, ISO 8601 format.
  *
  * @example
  * const date = new Date('2023-10-26T12:00:00Z');
  * console.log(formatSGT(date));
  * // Output: "2023-10-26T20:00:00.000000+08:00" (Example output in SGT)
  */
-export function formatSGT(date: Date): string {
-  const tzDate = new TZDate(date, "UTC");
+export function formatSGT(date: TZDate): string {
   return formatDate(
-    tzDate.withTimeZone("Asia/Singapore"),
+    date.withTimeZone("Asia/Singapore"),
     "yyyy-MM-dd'T'HH:mm:ss.SSSXX",
   );
 }
+
+/**
+ * Generates a range of dates based on a specified interval.
+ *
+ * @param begin - The start date of the range, inclusive.
+ * @param end - The end date of the range, exclusive.
+ * @param interval - The interval for generating dates. Options are:
+ *   - "day": Generates an array of dates at daily intervals.
+ *   - "hour": Generates an array of dates at hourly intervals.
+ *
+ * @returns An array of dates within the specified range, depending on the chosen interval.
+ */
+export function dateRange(begin: TZDate, end: TZDate, interval: DateInterval) {
+  const timespan = {
+    start: begin,
+    end: end,
+  };
+  if (interval === "day") {
+    return eachDayOfInterval(timespan);
+  }
+  if (interval == "hour") {
+    return eachHourOfInterval(timespan);
+  }
+}

backend/index.ts

@@ -24,6 +24,9 @@ if (process.argv.length < 4) {
 const apiYaml = process.argv[2];
 const port = parseInt(process.argv[3]);
 
+// fix timezone
+process.env.TZ = "Asia/Singapore";
+
 // setup services
 const db = initDB();
 const congestion = new CongestionSvc(db);