package ru.job4j;

import org.junit.Test;
import static org.hamcrest.core.Is.is;
import static org.junit.Assert.*;


public class CalculateTest {
    @Test
    public void whenSetStopInEchoThenReturnThreeStops() {
       
        Calculate calc = new Calculate();
        String result = calc.echo("stop");
        assertThat(result, is("stop stop stop"));
    }
    
 }
   

package ru.job4j;

import org.junit.Test;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import static org.hamcrest.core.Is.is;
import static org.junit.Assert.*;


public class CalculateTest {
    /**
    *Test add.
    */
    
    @Test
public void whenAddOneToOneThenTwo() { {
       
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        System.setOut(new PrintStream(out));
        Calculate.main(null);
        assertThat(out.toString(), is("Hello World\r\n"));
    }

    
        
    }
    
}
   

Update CalculateTest.java