helidon-tests-integration-mp-graphql fails with JDK 17

[barchetta]

Environment Details

• Helidon Version: 2.3.1-SNAPSHOT
• MP
• JDK version: java 17-ea 2021-09-14 LTS
• OS: Oracle Linux Server release 7.7

---

Problem Description

The test tests/integration/mp-graphql fails when built with JDK 17.

Steps to reproduce

1. Set JAVA_HOME to JDK 11 and do priming build of helidon repo: mvn clean install -DskipTests
2. Set JAVA_HOME to JDK 17 and build test:

cd tests/integration/mp-graphql
mvn clean install

Fails with:

[ERROR] io.helidon.microprofile.graphql.server.DateTimeIT.testDatesAndMutations  Time elapsed: 0.055 s  <<< FAILURE!
java.lang.AssertionError:

Expected: is "17 Feb. 1968"
     but: was "17 Feb 1968"
	at io.helidon.microprofile.graphql.server.DateTimeIT.testDatesAndMutations(DateTimeIT.java:253)

[tmiddlet2666]

This started failing with JDK13.

[tmiddlet2666]

Looks like this - https://bugs.openjdk.java.net/browse/JDK-8208487 which was "fixed" in 13.
I will remove the en-AU local tests as they are unpredictable.