I'm using SikuliX to test my game. Here's the code I'm running:
public void testApplication() throws FindFailed {
    // pass if there are merely no warnings/exceptions
    /* Example of using Jelly Tools (additional test dependencies required) with gui(true):
        new ActionNoBlock("Help|About", null).performMenu();
        new NbDialogOperator("About").closeByButton();
     */
    try {
        plugin.start(gameData, world);
        screen.wait("/Resources/playerStart.png");
    } catch (FindFailed ex) {
        System.out.println("PlayerStart failed!");
    }
    Assert.assertEquals(1, world.size());
    try {
        screen.wait("playerMoveForward.png");
        screen.type("wwwwwwww");
    } catch (FindFailed ex) {
        System.out.println("Player movement failed!");
    }
    try {
        screen.wait("playerTurnRight.png");
        screen.type("dddddddd");
    } catch (FindFailed ex) {
        System.out.println("Player turn failed!");
    }
}
I'm getting a null pointer on first screen.wait(), so the path is not right, and I have no idea how to get the right one. The full path of the image I'm trying to use is:
C:\Users\Jesper\Documents\NetBeansProjects\AsteroidTEST\AsteroidsTEST\application\src\test\java\Resources\playerStart.png
 
    