package lab.art;

import static org.junit.Assert.*;

import java.util.Random;

import org.junit.Test;

public class VariableXTester 
{
    @Test
    public void testConstructor() 
    {
	new VariableX();
    }
    
    @Test
    public void testToString()
    {
	VariableX expression = new VariableX();
	assertEquals("toString method failed", "x", expression.toString());
    }

    @Test
    public void testEvaluate()
    {
	Random random = new Random(System.currentTimeMillis());
	
	VariableX expression = new VariableX();
	
	int NUMBER = 1000;
	double DELTA = 0.0001;
	for (int n = 0; n < NUMBER; n++)
	{
	    double x = random.nextDouble();
	    if (random.nextBoolean())
	    {
		x = -x;
	    }
	    double y = random.nextDouble();
	    if (random.nextBoolean())
	    {
		y = -y;
	    }
	    assertEquals("evaluate method failed", x, expression.evaluate(x, y), DELTA);
	}
    }
}