Java 如何在 Junit 5 中替换 @Rule 注释？

How to replace @Rule annotation in Junit 5?

提问by IKo

I'm using wiremock in my tests and have such a line of code:

我在我的测试中使用了 wiremock 并且有这样一行代码：

@Rule
public WireMockRule wireMockRule = new WireMockRule(8080);

I want to switch to Junit 5. So I added the next dependency (using gradle):

我想切换到 Junit 5。所以我添加了下一个依赖项（使用 gradle）：

testCompile('org.junit.jupiter:junit-jupiter-engine:5.1.1')

But there no suggestions when I'm trying to import @Rule annotation. Do I need to add another module of junit dependency? Or rules are not supported in Junit5? If not how can I replace @Rule annotation to make tests work again? Thanks.

但是当我尝试导入 @Rule 注释时没有任何建议。我需要添加另一个junit依赖模块吗？还是 Junit5 不支持规则？如果不是，我该如何替换 @Rule 注释以使测试再次工作？谢谢。

采纳答案by davidxxx

In a general way, what you did with @Ruleand @ClassRulein JUnit 4 should be done with @ExtendWithand Extensionthat associated provide a very close feature in JUnit 5.
It works as standards JUnit lifecycle hooks but that it is extracted in a Extensionclass. And similarly to @Rule, as many Extensions as required may be added for a test class.

一般而言，您在 JUnit 4 中所做的@Rule和@ClassRule在 JUnit 4 中所做的都应该完成，@ExtendWith并且Extension相关联在 JUnit 5 中提供了一个非常接近的特性。
它作为标准的 JUnit 生命周期钩子工作，但它是在一个Extension类中提取的。与 类似@Rule，Extension可以为测试类添加所需数量的 s。

To handle the issue you have several possible approaches among :

要处理这个问题，您有几种可能的方法：

• keep the JUnit 4 way (JUnit 5 owns the JUnit Vintage part that allows to execute JUnit 3 or 4 tests).
• rewrite the @Ruleas an Extension.
• do the actual processing done by WireMockRule(start the server, execute your tests and stop the server) in each test of class with @BeforeEachand @AfterEachhook methods.
• use a third library that implements the equivalent of WireMockRule in the JUnit 5 Extension way such as https://github.com/lanwen/wiremock-junit5

• 保持 JUnit 4 的方式（JUnit 5 拥有允许执行 JUnit 3 或 4 测试的 JUnit Vintage 部分）。
• 将 重写@Rule为Extension.
• WireMockRule在类的每个测试中执行由（启动服务器，执行测试并停止服务器）完成的实际处理@BeforeEach和@AfterEach钩子方法。
• 使用在 JUnit 5 扩展方式中实现等效于 WireMockRule 的第三个库，例如https://github.com/lanwen/wiremock-junit5

Note that your issue already discussed in the JUnit 5 Issues.

请注意，您的问题已在JUnit 5 问题中讨论过。

回答by Arho Huttunen

JUnit 4 annotations @Ruleand @ClassRuledo not exist in JUnit 5. Basically there is a new extension model that can be used to implement extensions with the same functionality. These extensions can be used with the @ExtendWithannotation.

JUnit 4 注释@Rule并且@ClassRule在 JUnit 5 中不存在。基本上有一个新的扩展模型，可用于实现具有相同功能的扩展。这些扩展可以与@ExtendWith注释一起使用。

There is a limited migration support for a subset of JUnit 4 rules in the junit-jupiter-migrationsupportmodule. Unfortunately, it's only limited to subclasses of ExternalResourceand Verifier.

junit-jupiter-migrationsupport模块中对 JUnit 4 规则子集的迁移支持有限。不幸的是，它仅限于ExternalResource和的子类Verifier。

Before wiremock has official support for JUnit you have some workarounds:

在wiremock 正式支持JUnit 之前，您有一些解决方法：

1. Run JUnit 4 tests side by side with JUnit 5 tests with the junit-vintage-engine.
2. Start and stop the server yourself in the test code.
3. Use a 3rd party extension like wiremock-junit5or wiremock-extension.

1. 使用junit-vintage-engine并排运行 JUnit 4 测试和 JUnit 5 测试。
2. 在测试代​​码中自己启动和停止服务器。
3. 使用像wiremock-junit5或wiremock-extension这样的 3rd 方扩展。