cucumber-java8 does not work on OpenJDK 12+

When using OpenJDK 12+ in combination with cucumber-java8 users may experience class cast exceptions. See: Java+Cucumber execution error (java.lang.ClassCastException: class io.cucumber.docstring.DocString cannot be cast to class java.lang.String)

These occur because typetools is unable to read the parameter types from lambdas on OpenJDK 12+. See https://github.com/jhalterman/typetools/issues/52,

cucumber-java should not be affected. They’re separate modules since v4.0.0.

Resolving this requires fixing https://github.com/jhalterman/typetools/issues/52 to make TypeTools to work on Java 12+.

Update

The Cucumber team does not have resources available to fix this. We will deprecate cucumber-java8 at some point in the future.

[bestbeforetoday]

The fix in PR #1902 seems to have broken Cucumber tests that were previously running fine in OpenJDK 11.0.4, despite the failure message saying:

This version of cucumber-java8 is not compatible with Java 12+ See: https://github.com/cucumber/cucumber-jvm/issues/1817

The line that was previously working in Java 11 and is now failing is:

Given("I have deployed a {word} Fabric network", (String tlsType) -> {

I see this problem with cucumber-java8 version 5.7.0.

[mpkorstanje]

Good point. Could you create an issue in https://github.com/cucumber/docs and reference:

https://github.com/cucumber/cucumber-jvm/issues/2279