Create Unit tests for Testing Minesweeper in Eclipse/Java

gistfile1.txt

/**
 * The following test must be store in the root package of your Java project. The test is taked from the
 * Programming Styles WiSe 20-21 Basic Test Case. To make it work you need the following dependencies in your project:
 
 - JUnit 4.12
 - Hamcrest 2.2
 - Apache Commons Lang3 3.10
 - JUnit System Rules 1.19 (https://stefanbirkner.github.io/system-rules/download.html)
 
 * 
 * @author gambi
 */
import java.io.File;
import java.io.PrintWriter;

import org.junit.Rule;
import org.junit.Test;
import org.junit.contrib.java.lang.system.ExpectedSystemExit;
import org.junit.contrib.java.lang.system.SystemOutRule;
import org.junit.contrib.java.lang.system.TextFromStandardInputStream;
import org.junit.rules.TemporaryFolder;

public class GistTests {

	@Rule
	public TemporaryFolder tempFolder = new TemporaryFolder();

	// Make sure that JVM does not exit when MineSweeper calls System.exit
	@Rule
	public final ExpectedSystemExit exit = ExpectedSystemExit.none();

	@Rule
	public final TextFromStandardInputStream systemInMock = TextFromStandardInputStream.emptyStandardInputStream();

	@Rule
	public final SystemOutRule systemOutRule = new SystemOutRule().enableLog();

	@Test
	public void testThatGivenCorrectInputsTheProgramExitNormally() throws Exception {
		// Create a temporary file.
		final File boardCfgFile = tempFolder.newFile("simple.cfg");

		// Write the simple 3x3 board to the file
		try (PrintWriter out = new PrintWriter(boardCfgFile)) {
			out.println("..*");
			out.println("...");
			out.println("...");
		}

		// Provide the following lines on stdin
		systemInMock.provideLines("  1 1 R");
		
		// Define the expectation upon Exit Code
		// NOTE: This requires that main calls System.exit(0); otherwise the test fails !
		exit.expectSystemExitWithStatus(0);

		// Run the main method
		Minesweeper.main(new String[] { boardCfgFile.getAbsolutePath() });

		// here you can find the output produced by "Minesweeper" stored in a String 
		String stdOut = systemOutRule.getLog();

		System.out.println(" STD OUT IS \n" + stdOut);

	}

	@Test
	public void testNonRectangularConfiguration() throws Exception {
		// Create a file that has invalid content (lines have different lenght!)
		final File boardCfgFile = tempFolder.newFile("simple.cfg");

		try (PrintWriter out = new PrintWriter(boardCfgFile)) {
			out.println("...");
			out.println("*");
		}

// We expect that the system exits with exit code 2
		exit.expectSystemExitWithStatus(2);
		Minesweeper.main(new String[] { boardCfgFile.getAbsolutePath() });
	}

}