[java] SwitchStmtsShouldHaveDefault false positive on enum inside enums

[adangel]

Affects PMD Version: 6.29.0

Rule: SwitchStmtsShouldHaveDefault

Description:

If a switch-case over a enum is used inside the enum itself, PMD wrongly requests to add a default case, even though the switch statement is exhaustive. The switch is over this:

Code Sample demonstrating the issue:

package myPackage;

public enum GradeSystem {

    SysA, SysB;

    public boolean isValid() {
      switch (this) { // false-positive
        case SysA:
        case SysB:
          return true;
      }
      
      return false;
    }
}

Result:
myPackage/GradeSystem.java:8: Switch statements should have a default label

Expected outcome:

• Does PMD report a violation, where there shouldn't be one? -> false-positive

Running PMD through: CLI

[adangel]

This has been fixed with PMD 7.0.0-rc1.