package org.invisibletech;

import static org.junit.Assert.*;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.ExpectedException;

public class CanDetermineSignTest {
    @Rule public ExpectedException expectedException = ExpectedException.none();

    @Test
    public void shouldRaiseException_Given_NaNDouble() {
        expectedException.expect(IllegalArgumentException.class);
        expectedException.expectMessage("NaN");
        
        IndicateSign.signOf(Double.NaN);
    }

    @Test
    public void shouldReturnSign_Given_ZerosDouble() {
        assertEquals(-1, IndicateSign.signOf(-0.0));
        assertEquals(1, IndicateSign.signOf(0.0));
    }

    @Test
    public void shouldReturnSign_Given_DoubleInfinities() {
        assertEquals(1, IndicateSign.signOf(Double.POSITIVE_INFINITY));
        assertEquals(-1, IndicateSign.signOf(Double.NEGATIVE_INFINITY));
    }

    @Test
    public void shouldReturnSign_Given_Longs() {
        assertEquals(1, IndicateSign.signOf(Long.MAX_VALUE));
        assertEquals(-1, IndicateSign.signOf(Long.MIN_VALUE));
    }

}