在 JUnit 中，在每个“@Test”之后和每个“@After”之前应用“@Rule”

selenium java webdriver junit4 junit-rule

2022-09-02 12:32:25

我有一个测试套件，我正在注销系统并在.我正在尝试使用硒为每个测试方法使用失败的测试屏幕截图。我手动检查了仅在每个之前运行，但我想在之后和之前设置它。我找不到简单的解决方案。任何帮助将不胜感激。@After@AfterClass@Rule@Rule@Before@Test@After

public class MorgatgeCalculatorTest  {

@Before
public void before(){
    System.out.println("I am before");
}
@BeforeClass
public static void beforeclass(){
    System.out.println("I am beforeclass");
}
@Test
    public void test(){
        System.out.println("I am Test");
    }
@Test
public void test2(){
    System.out.println("I am Test2");
}
@After
    public void after(){
        System.out.println("I am after");
    }
@AfterClass
        public static  void afterclass(){
            System.out.println("I am afterclass");

}
@Rule
ExpensiveExternalResource ExpensiveExternalResource = new ExpensiveExternalResource();

static class ExpensiveExternalResource implements MethodRule  {
    public ExpensiveExternalResource(){
        System.out.println("I am rule");
    }

    @Override
    public Statement apply(Statement arg0, FrameworkMethod arg1, Object arg2) {
        // TODO Auto-generated method stub
        return null;
    }    
}

我得到的输出是

I am beforeclass
I am rule
I am before
I am Test
I am after
I am rule
I am before
I am Test2
I am after
I am afterclass

答案 1

由于规则的设置方式，您不能拥有@before之后或@after之前的规则。您可以考虑将规则视为放在测试方法上的 shell。第一个要进行的外壳是@before/@after。此后，将应用@rules。

做你想做的事情的一个快速方法是完全避免@After。可以创建一个规则，以便在方法失败时获取屏幕截图，然后在代码之后执行您的规则。它不像@After那么漂亮，但它有效。（我也实现了TestRule，因为MethodRule已经贬值了）。

public class MortgageCalculatorTest  {
    @Before
    public void before(){
        System.out.println("I am before");
    }

    @BeforeClass
    public static void beforeclass(){
        System.out.println("I am beforeclass");
    }

    @Test
    public void test(){
        System.out.println("I am a Test");
    }

    @Test
    public void test2(){
        System.out.println("I am a Failed Test");
        fail();
    }

    @AfterClass
            public static  void afterclass(){
                System.out.println("I am afterclass");

    }

    @Rule
    public ExpensiveExternalResource ExpensiveExternalResource = new ExpensiveExternalResource();

    public static class ExpensiveExternalResource implements TestRule  {


      //  public ExpensiveExternalResource(){}


        public class ExpansiveExternalResourceStatement extends Statement{

            private Statement baseStatement;

            public ExpansiveExternalResourceStatement(Statement b){
                baseStatement = b;
            }

            @Override
            public void evaluate() throws Throwable {
                try{
                    baseStatement.evaluate();
                }catch(Error e){
                    System.out.println("I take a Screenshot");
                    throw e;   
                }finally{
                    after();
                }
            }

            //Put your after code in this method!
            public void after(){
                System.out.println("I am after");
            }
        }

        public Statement apply(Statement base, Description description) {
            return new ExpansiveExternalResourceStatement(base);

        }


    }
}

规则的所有工作都在语句中完成。org.junit.runners.model.Statement 是一个表示一堆代码的类。因此，在这里，apply 方法接收您正在放置 shell 的代码包。Apply 返回您的语句，该语句执行您提供给它的代码包，并用 try/catch 语句将其括起来以捕获方法失败。

此方法的输出为：

I am beforeclass
I am before
I am a Test
I am after
I am before
I am a Failed Test
I take a Screenshot
I am after
I am afterclass

希望这有帮助！

答案 2

public class ScreenshotTestRule implements MethodRule {
    public Statement apply(final Statement statement, final FrameworkMethod frameworkMethod, final Object o) {
        return new Statement() {
            @Override
            public void evaluate() throws Throwable {
                try {
                    statement.evaluate();

                } catch (Throwable t) {
                    captureScreenshot(frameworkMethod.getName());
                    throw t; // rethrow to allow the failure to be reported to JUnit                     
                } finally {
                    tearDown();
                }
            }

            public void tearDown() {
                //logout to the system;
            }


            public void captureScreenshot(String fileName) {
                try {
                    new File("target/surefire-reports/screenshot").mkdirs(); // Insure directory is there
                    FileOutputStream out = new FileOutputStream("target/surefire-reports/screenshot/screenshot-" + fileName + ".png");
                    out.write(((TakesScreenshot) driver).getScreenshotAs(OutputType.BYTES));
                    out.close();
                } catch (Exception e) {
                    // No need to crash the tests if the screenshot fails
                }
            }
        };
    }
}