@Test
public void testMoveForward() throws Exception {
final Coords base = new Coords(0, 0);
final Coords northMove = NORTH.moveForward(NORTH.moveForward(NORTH.moveForward(base)));
assertEquals(new Coords(0, 3), northMove);
final Coords southMove = SOUTH.moveForward(SOUTH.moveForward(SOUTH.moveForward(base)));
assertEquals(new Coords(0, -3), southMove);
final Coords eastMove = EAST.moveForward(EAST.moveForward(EAST.moveForward(base)));
assertEquals(new Coords(3, 0), eastMove);
final Coords westMove = WEST.moveForward(WEST.moveForward(WEST.moveForward(base)));
assertEquals(new Coords(-3, 0), westMove);
}
@Test
public void testTurnLeft() throws Exception {
assertEquals(NORTH.turnLeft(), WEST);
assertEquals(WEST.turnLeft(), SOUTH);
assertEquals(SOUTH.turnLeft(), EAST);
assertEquals(EAST.turnLeft(), NORTH);
}