Exploring equals and hash code for Java 8 Lamdas

IdTest.java

package com.github.mperry;

import org.junit.Test;

import java.util.function.Function;

import static org.junit.Assert.assertTrue;

/**
 * Created by MarkPerry on 3/04/2014.
 */
public class IdTest {

    @Test
    public void simpleFuncId() {
        info(func1(), func1(), true);
    }

    @Test
    public void subFuncId() {
        info(subFunction().apply(null), subFunction().apply(null), true);
    }

    @Test
    public void equivalentFuncs() {
        info(func1(), func2(), false);
    }

    void info(Function<Integer, String> f1, Function<Integer, String> f2, boolean expected) {
        boolean eq = f1.equals(f2);
        int f1h = f1.hashCode();
        int f2h = f2.hashCode();
        boolean he = f1h == f2h;
        System.out.printf("f1=%s,f2=%s,f1h=%d,f2h=%d,eq=%b,he=%b\n", f1, f2, f1h, f2h, eq, he);
        assertTrue((f1 == f2) == expected);
    }

    Function<Integer, String> func1() {
        return (i -> i.toString());
    }

    Function<Integer, String> func2() {
        return (i -> i.toString());
    }

    Function<Void, Function<Integer, String>> subFunction() {
        return (v -> (i -> i.toString()));
    }

}