tests: support more-precise clocks in Java 11

[yaauie]

targets: master, 6.x (same targets as Java Plugin API that introduced these tests).

In Java 8, java.lang.Instant#now() used the system clock, which only had millisecond-level precision, but starting with Java 9, the system clock is much more precise.

Since we create our org.logstash.Timestamp with long epoch_milliseconds, it cannot represent a time more precisely than milliseconds.

Ensure that the output of Timestamp#usec is rounded before comparing it with milliseconds, in order to avoid asserting greater precision than we can create.

[yaauie]

Jenkins test this please

[danhermann]

Hmm, my original test was not that great in that it supplied millisecond precision for the seed value and then tested the microsecond component which would always be zero.

Edit: NVM, everything looks good. Math is hard. Or rather, the usec method on Timestamp follows Ruby conventions rather than the Java convention that getNanos does for Instant. Another consequence of mixing ecosystems.

[elasticsearch-bot]

Ry Biesemeyer merged this into the following branches!

Branch	Commits
6.x	c95eff6