...
<project>
...
    <dependencies>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
            <version>5.6.0</version>
            <scope>test</scope>
        </dependency>
            <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-params</artifactId>
            <version>5.6.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.6.0</version>
            <scope>test</scope>
        </dependency>
    </dependencies>
</project

import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
 
public class RechnerTest {
	Rechner rechner = new Rechner();
 
    public RechnerTest() {}
    @BeforeAll
    public static void setUpClass() {}
 
    @AfterAll
    public static void tearDownClass() {}
 
    @Test
    public void testPlus() {
        assertEquals(2.0, rechner.plus(1.0, 1.0), 0);
    }
 
    /**
     * Test of minus method, of class Rechner.
     */
    @Test
    public void testMinus() {
		assertEquals(0.0, rechner.minus(1.0, 1.0), 0);
    }
}