Can't use newer java.util.Map implementation with JavalinVue::stateFunction

I get this weird error as if I’m trying to set a null key:

JavalinVue.stateFunction = ctx -> Map.of(
    "currentMsisdn", ctx.sessionAttribute("currentMsisdn"), 
    "verifiedMsisdn", ctx.sessionAttribute("verifiedMsisdn")
);

java.lang.NullPointerException
        at java.base/java.util.Objects.requireNonNull(Objects.java:222)
        at java.base/java.util.ImmutableCollections$MapN.<init>(ImmutableCollections.java:964)
        at java.base/java.util.Map.of(Map.java:1328)
        ...

[fwgreen]

I’m guessing Map.of doesn’t accept null-values?

Ah! I see, and Context::sessionAttribute returns a nullable. Hopefully the Kotlin team will add a @JvmOptional annotation to their list of interop tools 😄. I’m closing the issue as the error is easily avoided by using the old Map, but maybe you can document the behavior so others can avoid this problem.

Thanks again for your quick reply.

[tipsy]

I’ll add the info label then 😃