feat: asDate support custom format and timezone using tempo

package.json

@@ -40,6 +40,7 @@
 		"*": "prettier --write --ignore-unknown"
 	},
 	"dependencies": {
+		"@formkit/tempo": "^0.1.2",
 		"@sinclair/typebox": "^0.33.19",
 		"d3-dsv": "^3.0.1"
 	},

src/transformer/as-date.ts

@@ -1,20 +1,67 @@
+import {
+	applyOffset,
+	format,
+	offset,
+	parse,
+	type Format,
+} from '@formkit/tempo';
 import { Date, type DateOptions } from '@sinclair/typebox';
 import { createTransformer } from './create-transformer';
 
 export type { DateOptions };
 
 /**
- * Create date transformer. Only accept {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_time_string_format | Date-time string format}.
- * @param options - Validation options (see {@link DateOptions})
+ * Options for Tempo to parse and format date string.
+ */
+export interface TempoOptions {
+	/**
+	 * The format that should be used to parse and format the date.
+	 * @defaultValue ISO 8601 format
+	 * @see {@link https://tempo.formkit.com/#format-tokens | Tempo Format Tokens}
+	 */
+	format?: Format;
+	/**
+	 * Timezone for the decode's input and encode's output date string.
+	 * @defaultValue UTC
+	 */
+	timezone?: string;
+}
+
+/**
+ * Create date transformer.
+ * Using {@link https://tempo.formkit.com | Tempo} to parse and format date string.
+ * @param options - {@link TempoOptions} for parsing/formatting and {@link DateOptions} for validation
+ * @remarks Without format option, asDate expects {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date#date_time_string_format | ISO 8601 format}
  * @example
  * ```ts
  * Column('createdAt', asDate());
+ * Column('createdAt', asDate({
+ *   format: 'DD/MM/YYYY',
+ *   timezone: 'Asia/Bangkok'
+ * }));
  * ```
  */
-export function asDate(options?: DateOptions) {
+export function asDate(options: TempoOptions & DateOptions = {}) {
+	const {
+		format: formatOption,
+		timezone = 'UTC',
+		...validateOptions
+	} = options;
+
 	return createTransformer(
-		(str) => new global.Date(str),
-		(date) => date.toISOString(),
-		Date(options),
+		(str) => {
+			const localDate = parse(str, formatOption);
+			return applyOffset(localDate, offset(localDate, timezone));
+		},
+		(date) =>
+			format({
+				date,
+				format: formatOption ?? 'YYYY-MM-DDTHH:mm:ss',
+				tz: timezone,
+			}) +
+			(formatOption === undefined
+				? `.${date.getMilliseconds().toString().padStart(3, '0')}Z`
+				: ''),
+		Date(validateOptions),
 	);
 }

tests/transformer/as-date.spec.ts

@@ -20,11 +20,13 @@ describe('default', () => {
 	it.each(['13/11/1996', 'not date'])(
 		'should throw when decode %p',
 		(value) => {
-			expect(() => Decode(asDate(), value)).toThrow('Expected Date');
+			expect(() => Decode(asDate(), value)).toThrow(
+				'Non ISO 8601 compliant date',
+			);
 		},
 	);
 
-	it('should encode date as ISO string', () => {
+	it('should encode date as string', () => {
 		const date = new Date();
 		const output = Encode(asDate(), date);
 		expect(output).toBe(date.toISOString());
@@ -36,6 +38,52 @@ describe('default', () => {
 			expect(() => Encode(asDate(), value)).toThrow('Expected Date');
 		},
 	);
+
+	it('should use custom format if given', () => {
+		const input = '13/11/1996';
+		const tfm = asDate({
+			format: 'DD/MM/YYYY',
+		});
+
+		const date = Decode(tfm, input);
+		expect(date).toBeValidDate();
+		expect(date.getDate()).toBe(13);
+		expect(date.getMonth()).toBe(10);
+		expect(date.getFullYear()).toBe(1996);
+
+		const string = Encode(tfm, date);
+		expect(string).toBe(input);
+	});
+
+	it('should use UTC timezone by default', () => {
+		const input = '1996-11-13T00:00';
+		const tfm = asDate();
+
+		const date = Decode(tfm, input);
+		expect(date).toBeValidDate();
+		expect(date.getMonth()).toBe(10);
+		expect(date.getDate()).toBe(13);
+		expect(date.getHours()).toBe(0);
+
+		const string = Encode(tfm, date);
+		expect(string).toStartWith(input);
+	});
+
+	it('should use custom timezone if given', () => {
+		const input = '1996-11-13T00:00';
+		const tfm = asDate({
+			timezone: 'Asia/Bangkok',
+		});
+
+		const date = Decode(tfm, input);
+		expect(date).toBeValidDate();
+		expect(date.getMonth()).toBe(10);
+		expect(date.getDate()).toBe(12);
+		expect(date.getHours()).toBe(17);
+
+		const string = Encode(tfm, date);
+		expect(string).toStartWith(input);
+	});
 });
 
 describe('optional', () => {