package fj;

import org.junit.Test;

import static org.hamcrest.MatcherAssert.assertThat;

import static org.hamcrest.core.Is.is;

public class EqualTest {

@Test

public void contramapShouldWork() {

Equal<String> equalByLength = Equal.contramap(String::length, Equal.intEqual);

assertThat(equalByLength.eq("str1", "str2"), is(true));

assertThat(equalByLength.eq("str1", "str11"), is(false));

}

@Test

public void thenShouldWork() {

Equal<String> equalByLengthThenLastDigit = Equal.on(String::length, Equal.intEqual)

.then(s -> s.charAt(s.length() - 1), Equal.charEqual).equal();

assertThat(equalByLengthThenLastDigit.eq("str1", "spr1"), is(true));

assertThat(equalByLengthThenLastDigit.eq("str1", "str2"), is(false));

assertThat(equalByLengthThenLastDigit.eq("str1", "strr1"), is(false));

}

}