Make value of SonarProperties#property nullable

[Vampire]

I'm porting a Groovy DSL build to Kotlin DSL.

Before I did things like

property('foo', [...] ?: null)

to override foo and either set it to some value or unset it otherwise.

In Kotlin DSL you cannot do

property("foo", listOf(...).takeIf { it.isNotEmpty() })

currently due to the @ParametersAreNonnullByDefault in the package-info.java and Kotlin respecting that, so having the value parameter non-nullable.
Work-around is to use

properties["foo"] = listOf(...).takeIf { it.isNotEmpty() }

or

listOf(...).also { if (it.isNotEmpty()) property("foo", it) else properties.remove("foo") }

This PR makes the value parameter nullable, so you can also use the first Kotlin snippet above.

[dorian-burihabwa-sonarsource]

hey @Vampire, thank you for the suggestion. Do you have any tests that effectively show that a nullable value actually removes the property from the collection?

[Vampire]

I don't really get your comment, sorry.

This is not a suggestion, but a definite bug report.

And it of course does not remove the property from the collection, why should it? It sets is value in the collection to null.

[dorian-burihabwa-sonarsource]

I don't really get your comment, sorry.

This is not a suggestion, but a definite bug report.

My bad, I did not understand what you were trying to achieve here.

And it of course does not remove the property from the collection, why should it? It sets is value in the collection to null.

Could you share, here or in the community forums, an example of a build configuration that triggers the bug?