junit5 动态测试

JUnit Jupiter @Nested annotation can be used to mark a nested class to be included in the test cases. When JUnit tests are executed, Nested classes are not scanned for test methods. We can explicitly mark them to be scanned for test cases using @Nested annotation.

JUnit Jupiter @Nested批注可用于标记要包含在测试用例中的嵌套类。 执行JUnit测试时，不会扫描嵌套类的测试方法。 我们可以使用@Nested批注明确标记要扫描的测试用例。

JUnit 5嵌套测试 (JUnit 5 Nested Tests)

JUnit Nested test classes should be non-static. Let’s look at a simple example of JUnit 5 Nested test class.

JUnit嵌套测试类应该是非静态的。 让我们看一个简单的JUnit 5嵌套测试类示例。

package com.journaldev.nested;import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;public class NestedTestSimpleExample {@Testvoid test() {System.out.println("Outer Class Test");}@Nestedclass InnerClass {@Testvoid test() {System.out.println("Inner Class Test");}}
}

Below image shows the JUnit execution report from Eclipse.

下图显示了Eclipse的JUnit执行报告。

If we remove @Nested annotation from the inner class, then the tests inside that will not be executed.

如果我们从内部类中删除@Nested批注，则其中的测试将不会执行。

JUnit嵌套测试回调方法 (JUnit Nested Tests Callback Methods)

Nested test classes can have their own @BeforeEach and @AfterEach methods. However, if outer class @BeforeEach and @AfterEach methods will also get executed for nested class tests. Let’s extend our example to confirm this behavior.

嵌套测试类可以具有自己的@BeforeEach和@AfterEach方法。 但是，如果外部类@BeforeEach和@AfterEach方法也将为嵌套类测试执行。 让我们扩展示例以确认此行为。

package com.journaldev.nested;import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;public class NestedTestSimpleExample {@BeforeAllstatic void setUpBeforeClass() throws Exception {System.out.println("@BeforeAll - Outer Class");}@AfterAllstatic void tearDownAfterClass() throws Exception {System.out.println("@AfterAll - Outer Class");}@BeforeEachvoid setUp() throws Exception {System.out.println("@BeforeEach - Outer Class");}@AfterEachvoid tearDown() throws Exception {System.out.println("@AfterEach - Outer Class");}@Testvoid test() {System.out.println("Outer Class Test");}@Nestedclass InnerClass {@BeforeEachvoid setUp() throws Exception {System.out.println("@BeforeEach - Inner Class");}@AfterEachvoid tearDown() throws Exception {System.out.println("@AfterEach - Inner Class");}@Testvoid test() {System.out.println("Inner Class Test");}}
}

The console output of JUnit Test Execution clearly confirms this behavior.

JUnit测试执行的控制台输出清楚地确认了此行为。

@BeforeAll - Outer Class@BeforeEach - Outer Class
Outer Class Test
@AfterEach - Outer Class@BeforeEach - Outer Class
@BeforeEach - Inner Class
Inner Class Test
@AfterEach - Inner Class
@AfterEach - Outer Class@AfterAll - Outer Class

If we want @BeforeAll and @AfterAll methods in the nested test class, then we have to explicitly set its lifecycle behavior to “per-class”. The default behavior of JUnit test cases is “per-method”.

如果要在嵌套测试类中使用@BeforeAll和@AfterAll方法，则必须将其生命周期行为显式设置为“每个类”。 JUnit测试用例的默认行为是“按方法”。

package com.journaldev.nested;import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Nested;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInstance;
import org.junit.jupiter.api.TestInstance.Lifecycle;class NestedExampleTest {@BeforeAllstatic void setUpBeforeClass() throws Exception {System.out.println("@BeforeAll - Outer Class");}@AfterAllstatic void tearDownAfterClass() throws Exception {System.out.println("@AfterAll - Outer Class");}@BeforeEachvoid setUp() throws Exception {System.out.println("@BeforeEach - Outer Class");}@AfterEachvoid tearDown() throws Exception {System.out.println("@AfterEach - Outer Class");}@Testvoid outer_test() {System.out.println("Outer Class test method");}@Nested@TestInstance(Lifecycle.PER_CLASS)class InnerClass {@BeforeAllvoid setUpBeforeClassInner() throws Exception {System.out.println("@BeforeAll - Inner Class");}@AfterAllvoid tearDownAfterClassInner() throws Exception {System.out.println("@AfterAll - Inner Class");}@BeforeEachvoid setUp() throws Exception {System.out.println("@BeforeEach - Inner Class");}@AfterEachvoid tearDown() throws Exception {System.out.println("@AfterEach - Inner Class");}@Testvoid inner_test() {System.out.println("Inner Class test method");}}
}

Here is the console output of JUnit test:

这是JUnit测试的控制台输出：

@BeforeAll - Outer Class@BeforeEach - Outer Class
Outer Class test method
@AfterEach - Outer Class@BeforeAll - Inner Class@BeforeEach - Outer Class
@BeforeEach - Inner Class
Inner Class test method
@AfterEach - Inner Class
@AfterEach - Outer Class@AfterAll - Inner Class
@AfterAll - Outer Class

摘要 (Summary)

JUnit Nested Classes can be used to categorize our test cases into different modules. But the same thing can be achieved by having multiple test classes.

JUnit嵌套类可用于将我们的测试用例分类到不同的模块中。 但是，通过具有多个测试类可以实现相同的目的。

翻译自: https://www.journaldev.com/21731/junit-nested-tests

junit5 动态测试