Predicate.not() method support is needed

[alisevych]

Description

In Java 11 there is a new static method introduced: Predicate.not()
Add its support for test generation.

To Reproduce

Steps to reproduce the behavior:

1. Set useFuzzing=false in settings.properties
2. A project with JDK 11 is opened in IntelliJ IDEA
3. Add the following Java class to it:

import java.util.function.Predicate;

public class test {

    public boolean testIsEqual(int a) {
        if (Predicate.isEqual(5).test(a)) {
            return true;
        } else {
            return false;
        }
    }

    public boolean testNot(int a) {
        if (Predicate.not(i -> i.equals(5)).test(a)) {
            return true;
        } else {
            return false;
        }
    }
}

4. Create tests with UTBot... for testIsEqual
5. Create tests with UTBot... for testNot

Expected behavior

4,5 Tests are generated successfully

Actual behavior

4. Tests are generated
5. Failed to generate tests error dialog is displayed.

Environment

IDEA 2022.1.3
Gradle project with JDK 11

[dtim]

Notes after a debugging session with @ArsenHD

Predicate.not() static method creates a nested lambda via the call to Predicate.negate() on its parameter. The outer lambda (negated predicate) captures this reference of the nested lambda (original predicate), we can see it as the cap0 field in the debugger.

There are several locations in the code (e.g., recordInstanceFieldRead) that tries to find a class to which this captured field belongs. As lambda does not have any "real" class which we could obtain by reflection (declaringClass, ClassId.jClass etc), the engine eventually fails with the ClassNotFoundException.

[alisevych]

@Damtev Please note that it's reproducing on the latest build from main