@GetMapping("/say_hello") public String sayHello(@RequestParam(defaultValue = "World") String name) { if (name == null || name.isEmpty()) { return "Hello World"; } else { return "Hello " + name; } } prueba unitaria crear

@Test
public void givenNull_whenSayingHello_thenReturnHelloWorld() {
    assertEquals(HelloController.sayHello(null), "Hello World");
}

@Test
public void givenEmptyString_whenSayingHello_thenReturnHelloWorld() {
    assertEquals(HelloController.sayHello(""), "Hello World");
}

@Test
public void givenString_whenSayingHello_thenReturnHelloString() {
    assertEquals(HelloController.sayHello("Test"), "Hello Test");
}