ISO8061Utils.parse() accepts non-existent dates

[JPedroAmorim]

Gson version

2.9.0

Java / Android version

java 16 2021-03-16
Java(TM) SE Runtime Environment (build 16+36-2231)
Java HotSpot(TM) 64-Bit Server VM (build 16+36-2231, mixed mode, sharing)

Description

Apparently ISO8061Utils.parse() works in a very lenient manner when dealing with dates that do not exist (for instance 2022-14-30), generating valid Date objects.

Given this unit test:

 @Test
    public void testDateParseNonExistentDate() throws ParseException {
        String dateStr = "2022-14-30";
        try {
            Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
            fail("Should've thrown exception");
        } catch (Exception expected) {

        }
    }

It fails and produces a Date object whose toString() yields:

Thu Mar 02 00:00:00 BRT 2023

This also applies for instances where the day is invalid as well.

 @Test
    public void testDateParseNonExistentDate() throws ParseException {
        String dateStr = "2022-12-33";
        try {
            Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
            fail("Should've thrown exception");
        } catch (Exception expected) {

        }
    }

It fails and produces a Date object whose toString() yields:

Mon Jan 02 00:00:00 BRT 2023

Expected behavior

An exception to be thrown, likely IllegalArgumentException.

Actual behavior

A valid Date object was generated that "absorbed" the surplus from the illegal argument.

Note

If this is expected behavior, let me know and I'll close the issue.

[Marcono1234]

I assume this was an oversight because when the date also has time information the value is parsed in strict mode, as desired. Have created #2134 to fix this issue. Though I am not a maintainer, so maybe that behavior has to be kept for backward compatibility (but I doubt it).

May I use your test methods in the pull request?

[JPedroAmorim]

Please, feel free to do so. Thanks!