Self-testing code is software that incorporates built-in tests (see test-first development). In Java, to execute a unit test from the command line, a class can have methods like the following. // Executing <code>main</code> runs the unit test. public static void main(String[] args) { test(); } static void test() { assert foo == bar; } To invoke a full system test, a class can incorporate a method call. public static void main(String[] args) { test(); TestSuite.test(); // invokes full system test }In addition, Java has some Jupiter API libraries for self-testing code. assert can be used in various ways such as assert equals, which checks if the given variable is equal to the value given.@Test void checkplayer() { Board board = new Board(10); board.addplayer(1); int check = board.getCurrentPlayer(1); assertEquals(1, check); } See also Software development Extreme programming References Articles with example Java code Unit testing