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javaseleniumwebdriverjunit4junit-rule

Apply '@Rule' after each '@Test' and before each '@After' in JUnit


I have a test suite where I am logging out of the system in @After and closing the browser in @AfterClass. I am trying to use @Rule to take failed test screenshot using Selenium for every test method. I checked manually that @Rule only runs before every @Before but I want to set it up after @Test and before @After. I couldn't find out simple solution. Any help will be appreciated.

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;
    }    
}               

The output I am getting is

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

Solution

  • Because of the way that rules are set up, you can't have a rule that comes after @before or before @after. You can think of rules like shells that you put on the test method. The first shell to go on is @before/@after. Thereafter the @rules are applied.

    A quick way to do what you want to do is to avoid @After altogether. A rule can be created so that it will take a screenshot if a method fails and then execute yours after the code. It isn't quite as pretty as @After, but it works. (also I implemented TestRule because MethodRule has been depreciated).

    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);
    
            }
    
    
        }
    }
    

    All the work of the rule is done in a statement. A org.junit.runners.model.Statement is a class that represents a bundle of code. So here the apply method receives the bundle of code that you are putting a shell around. Apply returns your statement that executes the bundle of code that you gave it and surrounds it with a try/catch statement to catch the method failures.

    The output for this method is:

    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
    

    Hope this helps!