P39Test.java

package com.shekhargulati.ninetynine_problems._02_arithmetic;

import org.junit.Test;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.junit.Assert.assertThat;

public class P39Test {

    @Test
    public void shouldSayPhiOf10Is4() throws Exception {
        long phi = P39.phi(10);
        assertThat(phi, equalTo(4L));
    }
}