Test-Driven Java Development, Second Edition - Second Edition

Test – board boundaries I

We should start by checking whether a piece is placed within the boundaries of the 3x3 board:

package com.packtpublishing.tddjava.ch03tictactoe;

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

public class TicTacToeSpec {
  @Rule
  public ExpectedException exception = ExpectedException.none();
  private TicTacToe ticTacToe;

  @Before
  public final void before() {
    ticTacToe = new TicTacToe();
  }  @Test
  public void whenXOutsideBoardThenRuntimeException() {
    exception.expect(RuntimeException.class);
    ticTacToe.play(5, 2);
  }
} 

When a piece is placed anywhere outside the x-axis, then RuntimeException is thrown.

In this test, we are defining that RuntimeException is ...