created Test for CountFileLine method

src/test/java/game/runGameTest.java

@@ -0,0 +1,41 @@
+package game;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+class runGameTest {
+
+	@BeforeEach
+	void setUp() throws Exception {
+	}
+
+	@Test
+	public void testCountFileLinesWithThreeLines() {
+		//arrange
+		int numLines = 0;
+	    File file;
+		try {
+			file = File.createTempFile("temp", ".txt");
+		    FileWriter writer = new FileWriter(file);
+		    writer.write("Zeile 1\n");
+		    writer.write("Zeile 2\n");
+		    writer.write("Zeile 3\n");
+		    writer.close();
+		    //act
+		    numLines = runGame.CountFileLines(file.getAbsolutePath());
+		} catch (IOException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		//assert
+	    assertEquals(4, numLines);
+	}
+
+
+}