July 2020
Intermediate to advanced
235 pages
3h 37m
Chinese
Content preview from Kotlin 编程实践
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147
第
9
章
测试
9.1
设置测试类的生命周期
问题
如何只在每个类中实例化 JUnit 5 测试一次，而不是每个测试函数都实例化一次。
解决方案
使用 @TestInstance 注解，或在
junitplaform.properties
文件中设置生命周期。
讨论
与本章中的许多小节一样，本节内容基于 Philipp Hauer 的
Best Practices for
Unit Testing in Kotlin
博客文章与演示文稿。
JUnit 4 默认会为测试类的每个测试方法都创建一个新的实例。这样可以确保每次都重新
初始化测试类的属性，从而使测试本身独立。缺点是每次测试都会反复执行实例化的代码。
为了避免在 Java 中出现这种情况，可以将类的任何属性标记为静态，并且可以将任何初
始化代码放入使用 @BeforeClass 注解的静态方法中，该方法仅执行一次。
作为示例，请考虑以下针对 java.util.List 的 JUnit 4 测试，参见示例 9-1。
148
｜
第
9
章
示例 9-1：使用 JUnit 4 对一个列表进行测试
public class JUnit4ListTests {
private static List<String> strings =
➊
Arrays.asList("this", ...
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