Added Test case when no ship is within the coordinates (isFree() method)

src/test/java/de/tims/fleetstorm/matchfield/MatchfieldShipTest.java

@@ -128,7 +128,7 @@ class MatchfieldShipTest {
 
 	@ParameterizedTest(name = "matchfield returns correct state if a position is free or not")
 	@MethodSource("testIsFreeMethod")
-	void testMatchfieldReturnsCorrectValueAboutFreeCoorinateSlots(String testName, Coordinate originCoordinate,
+	void testMatchfieldReturnsCorrectValueAboutFreeCoordinateSlots(String testName, Coordinate originCoordinate,
 			int direction, int length, Coordinate[] coordinatesWithShip, boolean expectedResult) {
 
 		Matchfield matchfield = new Matchfield(matchfieldSize);
@@ -144,7 +144,10 @@ class MatchfieldShipTest {
 	}
 
 	static Stream<Arguments> testIsFreeMethod() {
-		return Stream.of(Arguments.of("one ship is within the coordinates", new Coordinate(0, 0), 1, 2,
-				new Coordinate[] { new Coordinate(0, 0) }, false));
+		return Stream.of(
+				Arguments.of("one ship is within the coordinates", new Coordinate(0, 0), 1, 2,
+						new Coordinate[] { new Coordinate(0, 0) }, false),
+				Arguments.of("no ship is within the coordinates", new Coordinate(1, 1), 0, 5, new Coordinate[] {},
+						true));
 	}
 }