如何在@AfterEach执行前拦截JUnit 5中@BeforeEach的异常？

问题概述 #

JUnit 5存在一个问题：当@BeforeEach方法抛出异常时，无法在调用@AfterEach方法前对该异常进行拦截处理。@AfterTestExecutionCallback扩展仅能处理@Test方法执行过程中出现的异常，对@BeforeEach方法的异常无能为力，导致初始化阶段的异常无法被及时拦截。

复现代码 #

LogsWatcher.kt #

import org.junit.jupiter.api.extension.*
import org.junit.jupiter.api.fail


open class LogsWatcher : TestWatcher, BeforeEachCallback, AfterEachCallback, BeforeTestExecutionCallback,
    AfterTestExecutionCallback {

    override fun testFailed(context: ExtensionContext, cause: Throwable?) {
        failedLogs(context, object {}.javaClass.enclosingMethod.name)
        super.testFailed(context, cause)
    }

    open fun failedLogs(context: ExtensionContext?, methodName: String) {
        println("$methodName started")
        val testFailed = context?.executionException?.isPresent ?: fail("Test has no context")

        if (testFailed) {
            println("   $methodName: failed")

        }
    }

    override fun beforeEach(context: ExtensionContext?) {
        failedLogs(context, object {}.javaClass.enclosingMethod.name)
    }

    override fun afterEach(context: ExtensionContext?) {
        failedLogs(context, object {}.javaClass.enclosingMethod.name)
    }

    override fun beforeTestExecution(context: ExtensionContext?) {
        failedLogs(context, object {}.javaClass.enclosingMethod.name)
    }

    override fun afterTestExecution(context: ExtensionContext?) {
        failedLogs(context, object {}.javaClass.enclosingMethod.name)
    }
}

MyTest.kt #

import org.junit.jupiter.api.AfterEach
import org.junit.jupiter.api.Assertions
import org.junit.jupiter.api.BeforeEach
import org.junit.jupiter.api.Test
import org.junit.jupiter.api.extension.ExtendWith

@ExtendWith(LogsWatcher::class)
class MyTest {
    @BeforeEach
    fun preCondition(){
        println("@BeforeEach start")
        Assertions.assertTrue(false)
        println("@BeforeEach stop")
    }

    @Test
    fun myTest(){
        println("Test start")
        Assertions.assertTrue(false)
        println("Test stop")
    }

    @AfterEach
    fun postCondition1(){
        println("@AfterEach 1")
    }

    @AfterEach
    fun postCondition2(){
        println("@AfterEach 2")
    }
}

执行输出 #

当@BeforeEach执行失败时的输出 #

beforeEach started
@BeforeEach start
@AfterEach 1
@AfterEach 2
afterEach started
   afterEach: failed
testFailed started
   testFailed: failed

当@Test执行失败时的输出 #

beforeEach started
@BeforeEach start
@BeforeEach stop
beforeTestExecution started
Test start
afterTestExecution started
   afterTestExecution: failed
@AfterEach 1
@AfterEach 2
afterEach started
   afterEach: failed
testFailed started
   testFailed: failed

解决方案进展 #

此前提交相关问题至JUnit官方仓库，暂未得到有效回复。后续收到官方提示，可尝试使用LifecycleMethodExecutionExceptionHandler处理该场景，相关内容会进一步更新。

内容的提问来源于stack exchange，提问作者Michael Fleytman