'instanceof' with incompatible interface

Reports instanceof expressions where the compared type is an interface, and the compared expression has a class type that neither implements the compared interface, nor has any visible subclasses which implement the compared interface.

Although that might be intended, normally such a construct is most likely an error, where the resulting instanceof expression always evaluates to false.

Example:

interface I1 {}

interface I2 {}

interface I3 extends I1 {}

static class Sub1 implements I1 {}

static class Sub2 extends Sub1 implements I2 {
  void test(Sub1 sub1) {
    if (sub1 instanceof I3) { // here 'I3' is incompatible interface
    }
  }
}

Inspection Details
Available in:	IntelliJ IDEA 2023.3, Qodana for JVM 2023.3
Plugin:	Java, 233.SNAPSHOT

Last modified: 13 July 2023