Add support for 9-digit millisecond precision to isoTimestamp #348

ISO-8601 does not specify the number of digits in the decimal fraction.

JavaScript `new Date().toISOString()` which is compliant to ISO-8601, has a precision of three digits (miliseconds precision).
Java `Instant.now().toString()` which is compliant to ISO-8601, has a precision of nine digits (nanoseconds precision).

This change will allow timestamps with nanoseconds precision.

library/src/regex.ts

@@ -79,7 +79,7 @@ export const ISO_TIME_SECOND_REGEX = /^(?:0\d|1\d|2[0-3])(?::[0-5]\d){2}$/u;
  * [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) timestamp regex.
  */
 export const ISO_TIMESTAMP_REGEX =
-  /^\d{4}-(?:0[1-9]|1[0-2])-(?:[12]\d|0[1-9]|3[01])T(?:0\d|1\d|2[0-3])(?::[0-5]\d){2}\.\d{3}Z$/u;
+  /^\d{4}-(?:0[1-9]|1[0-2])-(?:[12]\d|0[1-9]|3[01])T(?:0\d|1\d|2[0-3])(?::[0-5]\d){2}\.\d{3,9}Z$/u;
 
 /**
  * [ISO 8601](https://en.wikipedia.org/wiki/ISO_8601) week regex.

library/src/validations/isoTimestamp/isoTimestamp.test.ts

@@ -10,6 +10,8 @@ describe('isoTimestamp', () => {
     expect(validate._parse(value2).output).toBe(value2);
     const value3 = '9999-12-31T23:59:59.999Z';
     expect(validate._parse(value3).output).toBe(value3);
+    const value4 = '2024-01-04T17:40:21.157953900Z';
+    expect(validate._parse(value4).output).toBe(value4);
 
     expect(validate._parse('').issues).toBeTruthy();
     expect(validate._parse('2023-07-11T17:26:27.243').issues).toBeTruthy();

library/src/validations/isoTimestamp/isoTimestamp.ts

@@ -20,7 +20,15 @@ export type IsoTimestampValidation<TInput extends string> =
 /**
  * Creates a pipeline validation action that validates a timestamp.
  *
- * Format: yyyy-mm-ddThh:mm:ss.sssZ
+ * Format: yyyy-mm-ddThh:mm:ss.sssssssssZ
+ *   - yyyy: 4-digit year
+ *   - mm: 2-digit month
+ *   - dd: 2-digit day
+ *   - hh: 2-digit hour (00-23)
+ *   - mm: 2-digit minute (00-59)
+ *   - ss: 2-digit second (00-59)
+ *   - sssssssss: Up to 9-digit millisecond precision
+ *   - Z: Timezone offset (e.g., +00:00 or -07:00, Z=UTC+0)
  *
  * Hint: The regex used cannot validate the maximum number of days based on
  * year and month. For example, "2023-06-31T00:00:00.000Z" is valid although