feat(datetime): format() options

datetime/_common.ts

@@ -102,7 +102,7 @@ interface DateTimeFormatPart {
 
 type TimeZone = "UTC";
 
-interface Options {
+export interface Options {
   timeZone?: TimeZone;
 }
 

datetime/format.ts

@@ -1,7 +1,7 @@
 // Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
 // This module is browser compatible.
 
-import { DateTimeFormatter } from "./_common.ts";
+import { DateTimeFormatter, Options } from "./_common.ts";
 
 /**
  * Takes an input `date` and a `formatString` to format to a `string`.
@@ -22,9 +22,14 @@ import { DateTimeFormatter } from "./_common.ts";
  *
  * @param date Date
  * @param formatString Format string
+ * @param options Format options
  * @return formatted date string
  */
-export function format(date: Date, formatString: string): string {
+export function format(
+  date: Date,
+  formatString: string,
+  options?: Options,
+): string {
   const formatter = new DateTimeFormatter(formatString);
-  return formatter.format(date);
+  return formatter.format(date, options);
 }

datetime/format_test.ts

@@ -102,5 +102,14 @@ Deno.test({
       "1",
       format(new Date("2019-01-01T13:00:00.000"), "h"),
     );
+
+    assertEquals(
+      "2019-01-01 04:00:00.000",
+      format(
+        new Date("2019-01-01T13:00:00.000+09:00"),
+        "yyyy-MM-dd HH:mm:ss.SSS",
+        { timeZone: "UTC" },
+      ),
+    );
   },
 });