RFR: 8366224: Introduce DecimalDigits.appendPair for efficient two-digit formatting and refactor DateTimeHelper [v18]

[Roger Riggs]

On Thu, 13 Nov 2025 06:01:05 GMT, Shaojin Wen <swen at openjdk.org> wrote:

>> test/jdk/jdk/internal/util/DecimalDigitsTest.java line 36:
>> 
>>> 34:  * @summary Test DecimalDigits.appendPair method with LATIN1 and UTF16 encoding
>>> 35:  * @modules java.base/jdk.internal.util
>>> 36:  * @run testng test.jdk.internal.util.DecimalDigitsTest
>> 
>> We recommend using junit for new tests.
>
> import org.junit.jupiter.api.Test;
> import static org.junit.jupiter.api.Assertions.assertEquals;
> 
> 
> Using JUnit 5 will cause an error:
> 
> /Users/wenshao/Work/git/jdk/test/jdk/jdk/internal/util/DecimalDigitsTest.java:27: error: package org.junit.jupiter.api does not exist
> import static org.junit.jupiter.api.Assertions.assertEquals;

testng is fine, for consistency within the java.time tests, all of which use testng.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26911#discussion_r2524705231