GeoTools gt-jdbc-postgis online tests and GeoServer app-schema online tests all pass using PostgreSQL 10 RC 1 with PostGIS 2.4.0. Tested on master with OpenJDK 8:
debian/sid amd64
postgresql-10 10~rc1-1 amd64
postgresql-10-postgis-2.4 2.4.0+dfsg-1 amd64
openjdk-8-jdk 8u144-b01-2 amd64
Apache Maven 3.5.0 (ff8f5e7444045639af65f6095c62210b5713f426; 2017-04-04T07:39:06+12:00)
Maven home: /home/ben/java/maven
Java version: 1.8.0_144, vendor: Oracle Corporation
Java home: /usr/lib/jvm/java-8-openjdk-amd64/jre
Default locale: en_GB, platform encoding: UTF-8
OS name: "linux", version: "4.12.0-2-amd64", arch: "amd64", family: "unix"
Kind regards,
--
Ben Caradoc-Davies <ben@anonymised.com>
Director
Transient Software Limited <http://transient.nz/>
New Zealand