Testng 简明教程

TestNG - Basic Annotations - Transformers

在某些情况下，您可能希望根据一些条件或标准执行 TestNG 测试，这些条件或标准在测试执行过程中动态评估。例如：

In some scenarios you might want to execute TestNG tests based on some condition or criteria that is evaluated dynamically while test execution is in progress.Such as :

  1. Enable or disable a test

  2. Add data provider at run time

为此，您需要使用注解转换器。注解转换器是一个实现了以下接口的类：

In order to achieve this, you need to use an Annotation Transformer. An Annotation Transformer is a class that implements the following interface:

  public interface IAnnotationTransformer {

  /**
   * This method will be invoked by TestNG to give you a chance
   * to modify a TestNG annotation read from your test classes.
   * You can change the values you need by calling any of the
   * setters on the ITest interface.
   *
   * Note that only one of the three parameters testClass,
   * testConstructor and testMethod will be non-null.
   *
   * @param annotation The annotation that was read from your
   * test class.
   * @param testClass If the annotation was found on a class, this
   * parameter represents this class (null otherwise).
   * @param testConstructor If the annotation was found on a constructor,
   * this parameter represents this constructor (null otherwise).
   * @param testMethod If the annotation was found on a method,
   * this parameter represents this method (null otherwise).
   */
  public void transform(ITest annotation, Class testClass,
      Constructor testConstructor, Method testMethod);
  }

您可以按如下所示在命令行或使用 ant 指定此类：

You can specify this class either on the command line or with ant as shown below:

  java org.testng.TestNG -listener TestTransformer testng.xml

或按如下所示以编程方式指定：

or programmatically as shown below:

  TestNG test = new TestNG();
  test.setAnnotationTransformer(new TestTransformer());
  // ...

此接口 IAnnotationTransformer 修改了运行时中默认的 TestNG 测试行为。使用此监听器，我们可以通过调用其 set 方法修改 @Test 注解中定义的所有属性的值。

This interface IAnnotationTransformer modifies the default TestNG tests behavior at run time. Using this listener, we can modify values of all attributes defined in @Test annotation by calling their setters.

Create a Class

让我们在以下示例中了解注解转换器的用法。我们可以跳过标记到指定组的测试，而不必每次都更改 TestNG 套件。创建一个要测试的 Java 类，例如 ListenerTest.java ，位于 /work/testng/src 。

Let’s see the usage of annotation transformer in below example. Let us skip tests that are tagged to a specified group without changing TestNG suite every time. Create a java class to be tested, say, ListenerTest.java in /work/testng/src.

  import org.testng.annotations.Test;

  public class ListenerTest {
  	@Test(groups={"betaTest","aplhaTest"})
  	public void test1() {
  		System.out.println("I am test1");
  	}

  	@Test(groups={"aplhaTest"})
  	public void test2() {
  		System.out.println("I am test2");
  	}
  }

Create Tansformer class Case Class

  1. Create a java test class, say, TestTransformer.java(that implements IAnnotationTransformer) in /work/testng/src.

  2. Override method transform().

  3. Add an Annotation @Test to methods test1() and test2() and group them.

  4. Add logic to skip tests with group name betaTest.

以下是 TestTransformer.java 的内容。

Following are the TestTransformer.java contents.

  import java.lang.reflect.Constructor;
  import java.lang.reflect.Method;
  import java.util.Arrays;
  import java.util.List;

  import org.testng.IAnnotationTransformer;
  import org.testng.annotations.ITestAnnotation;

  public class TestTransformer implements IAnnotationTransformer{
  	@Override
  	public void transform(ITestAnnotation annotation, Class testClass,
  			Constructor testConstructor, Method testMethod) {

  		List groupNames = Arrays.asList(annotation.getGroups());
  		System.out.println(groupNames.toString());
  		//Value 'betaTest' can be read from many places like properties file, run time parameter etc...
  		//For Simplicity, group is hardcoded in this program

  		String groupNameToSkip = "betaTest";

  		if(groupNames.contains(groupNameToSkip)){
  			System.out.println("found group name");
  			annotation.setEnabled(false);
  		}
  	}
  }

Create testng.xml

接下来，让我们在 /work/testng/src 中创建一个 testng.xml 文件来执行测试用例。

Next, let’s create testng.xml file in /work/testng/src, to execute test case(s).

  <suite name="Suite" parallel="classes" thread-count="2">
  <listeners>
    <listener class-name="TestTransformer"></listener>
  </listeners>
  <test name="Test">
    <classes>
      <class name="ListenerTest"/>
    </classes>
  </test>
</suite>

使用 javac 编译测试用例。

Compile the test case using javac.

/work/testng/src$ javac TestTransformer.java ListenerTest.java

现在，运行 testng.xml，这将运行 <test> 标签中定义的测试用例。正如您所看到的，分组在名称 betaTest 下的测试已被跳过。

Now, run the testng.xml, which will run the test case defined in <test> tag. As you can see the tests grouped under name betaTest are skipped.

/work/testng/src$ java org.testng.TestNG testng.xml

验证输出。

Verify the output.

  [aplhaTest]
  [betaTest, aplhaTest]
  found group name
  I am test2

  ===============================================
  Suite
  Total tests run: 1, Passes: 1, Failures: 0, Skips: 0
  ===============================================