Some example of Junit of Rest Api : I wanna to try some example of junit with rest api, i m a beginner of j unit and i don t know how to start

nothing to test

My Repository:

    @Repository
    public interface ClienteRepository extends JpaRepository<ClienteEntity, Integer>{
    	ClienteEntity findByEmail(@Param("email") String email);
    	 
    	
    	 @Query(value = "SELECT u FROM ClienteEntity u where u.email = ?1 and u.password = ?2 ")
    	    Optional<ClienteEntity> login(String email,String password);
    
    	    Optional<ClienteEntity> findByToken(String token);
    	    
    	    
    	    
    		@Query(value = "SELECT c " +  
    				"FROM ClienteEntity c " +
    				"WHERE c.id = :id ")
    		
    		ClienteEntity getClienteById(@Param("id")Integer id);
    	    
    		
    	
    }

Had an entity "cliente" with these fields: 

    @Id
    	@GeneratedValue(strategy=GenerationType.AUTO) //Vedere UUID bene
    	private Integer id;
    	
    	private String nome;
    	
    	private String cognome;
    	
    	@Column(name = "email", unique = true)
    	private String email ;
    	
    	private String password;
    	
    	private String citta;
    	
    	private String cap;
    	
    	private String indirizzo;
    	
    	private String token;
    	
    	public String getToken() {
    		return token;
    	}
    
    with their set and get methods

i wanna for example test a "cliente" means "user" by email
and wanna test on fields instead my db

