带有注释为@RegisterExtension的字段的 JUnit 5 测试在 Kotlin 中不起作用

发布于08月29日

我有一个用Java编写的JUnit 5测试类，它使用一个注释为@RegisterExtension的字段，它工作得很好:

class RegisterExtensionTest {

    @RegisterExtension
    LoggingExtension log = new LoggingExtension(RegisterExtensionTest.class);

    @Test void demoTest() {
        ...
    }
}

When I convert it to Kotlin:

class RegisterExtensionTest {

     @RegisterExtension
     var log = LoggingExtension(RegisterExtensionTest::class.java)

     @Test
     fun demoTest() {
        ...
    }
}

现在LoggingExtension不再跑了.为什么？

推荐答案

As documented here, just add a @JvmField annotation to the field, and it works.

class RegisterExtensionTest {

     @JvmField
     @RegisterExtension
     var log = LoggingExtension(RegisterExtensionTest::class.java)

     @Test
     fun demoTest() {
        ...
    }
}

The extension field has to be public (and JUnit doesn't warn you if it isn't), but in Kotlin, a property creates a private field and a getter in the byte code, so JUnit doesn't see it.