false possitive on "Possible null pointer dereference of null" on lateinit var

[yangzii0920]

gradle version: 8.9
spotbugs plugin version: 5.2.5

The original failure I encountered was from a @SpringBootTest. To simplify it for reproduction:

//Test.kt
@SpringBootTest
class Test {

    @Autowired
    private lateinit var bean: SomeClass

    @Test
    fun example() {
        assertThat("a").isNotEqualTo(bean.getBeanProperty())
    } 
}

In the example, getBeanProperty() might return null, but if I replace bean.getBeanProperty() with null, spotbugs succeeded. That makes me wonder if it was complaining about the fact that bean object could be null. So I change to test a little to decouple it from Spring:

//Test.kt
class Test {

    private lateinit var str: String

    @Test
    fun example() {
        str.length
    } 
}

and it fails on the same error M C NP: Possible null pointer dereference of null in xxx.Test.example() Dereferenced at Test.kt:[line xx]

Even if I instantiate the object (but not in the same test function), it would still think the str could be null:

//Test.kt
class Test {

    private lateinit var str: String

    @BeforeEach
    fun init() {str = "123"}

    @Test
    fun example() {
        str.length
    } 
}