SampleGame.java

package com.github.miyohide;

public class SampleGame {

    public String play(String p1, String p2) {
        if ((p1.equals("rock") && p2.equals("scissors")) ||
                (p1.equals("scissors") && p2.equals("paper"))
        ) {
            return "player1Win";
        }
        return "";
    }
}

SampleGameTest.java

package com.github.miyohide;

import org.junit.jupiter.api.Test;

import static org.junit.jupiter.api.Assertions.assertEquals;

public class SampleGameTest {
    @Test
    void rock_vs_scissors_player1Win() {
        assertEquals("player1Win", new SampleGame().play("rock", "scissors"));
    }
    @Test
    void scissors_vs_paper_player1Win() {
        assertEquals("player1Win", new SampleGame().play("scissors", "paper"));
    }
}