JUnit5 快速指南
version: junit5
1. 安装
在 pom 中添加依赖
<properties>
<junit.jupiter.version>5.3.2</junit.jupiter.version>
</properties>
<dependencies>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<version>${junit.jupiter.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-params</artifactId>
<version>${junit.jupiter.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>${junit.jupiter.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
组件间依赖关系：
2. JUnit 注解
| Annotation | Description |
|---|---|
@Test |
Denotes that a method is a test method. Unlike JUnit 4’s @Test annotation, this annotation does not declare any attributes, since test extensions in JUnit Jupiter operate based on their own dedicated annotations. Such methods are inherited unless they are overridden. |
@ParameterizedTest |
Denotes that a method is a parameterized test. Such methods are inherited unless they are overridden. |
@RepeatedTest |
Denotes that a method is a test template for a repeated test. Such methods are inherited unless they are overridden. |
@TestFactory |
Denotes that a method is a test factory for dynamic tests. Such methods are inherited unless they are overridden. |
@TestInstance |
Used to configure the test instance lifecycle for the annotated test class. Such annotations are inherited. |
@TestTemplate |
Denotes that a method is a template for test cases designed to be invoked multiple times depending on the number of invocation contexts returned by the registered providers. Such methods are inherited unless they are overridden. |
@DisplayName |
Declares a custom display name for the test class or test method. Such annotations are not inherited. |
@BeforeEach |
Denotes that the annotated method should be executed before each @Test, @RepeatedTest, @ParameterizedTest, or @TestFactory method in the current class; analogous to JUnit 4’s @Before. Such methods are inherited unless they are overridden. |
@AfterEach |
Denotes that the annotated method should be executed after each @Test, @RepeatedTest, @ParameterizedTest, or @TestFactory method in the current class; analogous to JUnit 4’s @After. Such methods are inherited unless they are overridden. |
@BeforeAll |
Denotes that the annotated method should be executed before all @Test, @RepeatedTest, @ParameterizedTest, and @TestFactory methods in the current class; analogous to JUnit 4’s @BeforeClass. Such methods are inherited (unless they are hidden or overridden) and must be static (unless the "per-class" test instance lifecycle is used). |
@AfterAll |
Denotes that the annotated method should be executed after all @Test, @RepeatedTest, @ParameterizedTest, and @TestFactory methods in the current class; analogous to JUnit 4’s @AfterClass. Such methods are inherited (unless they are hidden or overridden) and must be static (unless the "per-class" test instance lifecycle is used). |
@Nested |
Denotes that the annotated class is a nested, non-static test class. @BeforeAll and @AfterAllmethods cannot be used directly in a @Nested test class unless the "per-class" test instance lifecycle is used. Such annotations are not inherited. |
@Tag |
Used to declare tags for filtering tests, either at the class or method level; analogous to test groups in TestNG or Categories in JUnit 4. Such annotations are inherited at the class level but not at the method level. |
@Disabled |
Used to disable a test class or test method; analogous to JUnit 4’s @Ignore. Such annotations are not inherited. |
@ExtendWith |
Used to register custom extensions. Such annotations are inherited. |
3. 编写单元测试
3.1. 基本的单元测试类和方法
import org.junit.jupiter.api.*;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
class Junit5StandardTests {
private static final Logger LOGGER = LoggerFactory.getLogger(Junit5StandardTests.class);
@BeforeAll
static void beforeAll() {
LOGGER.info("call beforeAll()");
}
@BeforeEach
void beforeEach() {
LOGGER.info("call beforeEach()");
}
@Test
void succeedingTest() {
LOGGER.info("call succeedingTest()");
}
@Test
void failingTest() {
LOGGER.info("call failingTest()");
// fail("a failing test");
}
@Test
@Disabled("for demonstration purposes")
void skippedTest() {
LOGGER.info("call skippedTest()");
// not executed
}
@AfterEach
void afterEach() {
LOGGER.info("call afterEach()");
}
@AfterAll
static void afterAll() {
LOGGER.info("call afterAll()");
}
}
3.2. 定制测试类和方法的显示名称
支持普通字符、特殊符号、emoji
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
@DisplayName("A special test case")
class JunitDisplayNameDemo {
@Test
@DisplayName("Custom test name containing spaces")
void testWithDisplayNameContainingSpaces() { }
@Test
@DisplayName("╯°□°）╯")
void testWithDisplayNameContainingSpecialCharacters() { }
@Test
@DisplayName("