SonarQube Java – Boolean literals should not be redundant – True/Null

January 11, 2022

I have the followin snippet inside a method:

public void foo(Bar bar){
    this.setSomeField(bar.equals(somePredefinedObject) ? null : true);
}

Sonarqube complains about using the literal true in there.
I feel like I can’t just get rid of it so easily, because if that expression evaluates to false, I don’t pass in false but rather pass in null. For evaluation to true, I pass in true.

Any ideas on how I could go about making sonarqube happy here?

>Solution :

This is SonarQube rule RSPEC-1125

The solution that they recommend is to change

booleanVariable = booleanMethod() ? exp : true;

booleanVariable = !booleanMethod() || exp;

Unfortunately, it doesn’t work with three-valued logic involving Boolean.TRUE, Boolean.FALSE and null.

Instead, I think that you should¹ write it like this:

public void foo(Bar bar){
    if (bar.equals(somePredefinedObject) {
       this.setSomeField(null);
    } else {
       this.setSomeField(true);
    }
}

Or suppress this particular case.

Arguably, the SonarQube rule is giving a false positive here, though it could also be argued that implementing 3-values logic in this way is a bad idea.

^{1 – It is possible that you could trick SonarQube by using a variable containing a reference to Boolean.TRUE, but that is going to make your code harder for other people to read. (Expect comments like "why the heck did you do that??")}