Validation of timestamp with ISO8601 pattern with microseconds fails

[kevinwallimann]

Describe the bug

The following timestamp pattern fails to be validated: yyyy-MM-dd'T'HH:mm:ss.SSSXXX. This is a pattern defined by ISO8601. However, it does validate when removing either the 'T' or the fractional second part (see test-cases below)

To Reproduce

Steps to reproduce the behavior OR commands run:

1. Add the following test to SchemaValidationSuite and execute it

  test("Timestamp with fractional seconds should be validated") {
    val schema = StructType(
      Array(
        StructField("id", LongType),
        StructField("name", StringType),
        StructField("timestamp_without_fraction_ok", TimestampType, nullable = false, Metadata.fromJson(""" { "pattern": "yyyy-MM-dd'T'HH:mm:ssXXX", "default": "2025-01-08T13:07:39+00:00" } """.stripMargin)),
        StructField("timestamp_with_fraction_without_T_ok", TimestampType, nullable = false, Metadata.fromJson(""" { "pattern": "yyyy-MM-dd HH:mm:ss.SSSXXX", "default": "2025-01-08 13:07:39.490+00:00" } """.stripMargin)),
        StructField("timestamp_with_fraction_and_T_nok", TimestampType, nullable = false, Metadata.fromJson(""" { "pattern": "yyyy-MM-dd'T'HH:mm:ss.SSSXXX", "default": "2025-01-08T13:07:39.490+00:00" } """.stripMargin))
      )
    )

    val failures = SchemaValidator.validateSchema(schema)(CommonTypeDefaults)
    if (failures.nonEmpty) {
      logger.error("Validation errors:")
      logger.error(failures.mkString("\n"))
    }

    assert(failures.isEmpty)
  }

2. See the test failing with Unparseable date: "2025-01-08T13:07:39.490:00

Expected behavior

The pattern with 'T' and fractional seconds should be successfully validated.

Use-case

Only for internal development / testing

[KarinKersten]

It's still broken, but it doesn't affect any business users so far. It's not important and not urgent