Hard Assertion - assertNull(object) in Webdriver Assertion

-> assertNull(object) assertion will check and verify that object is NULL.

-> It will pass if object returns Null. and continue the execution

-> It will fail if object returns any value. then it will return error message like "java.lang.AssertionError: expected [null] but found [true]". Whenever your assertion fails, it will mark that specific test method as fail in TestNG result.



Example :

Let us take example like we have two text box. one is Enabled in application. Second is disabled in application.


   WebElement txt1, txt2;
 @BeforeClass
 public void load_url(){
  driver.get("google.com");
  txt1 = driver.findElement(By.xpath("//input[@id='text1']"));
  txt2 = driver.findElement(By.xpath("//input[@id='text2']"));
 }

 //Example Of Assertion Method - will Pass
 @Test
 public void null1() {
  System.out.print("\n"+txt1.getAttribute("disabled"));
  Assert.assertNull(txt1.getAttribute("disabled"));
 }

 //Example Assertion Method - will Fail
 @Test
 public void null2() {
  System.out.print("\n"+txt2.getAttribute("disabled"));
  Assert.assertNull(txt2.getAttribute("disabled"));
 }



From the above example


First Text box -> Enabled="True". Its dont have Disabled attribute. So its returns NULL.

Second Text box -> Disabled="True". Its dont have Disabled attribute. So its returns value.


So o/p will be


-> null1() will get pass, because its not have the disabled attribute. So its return Null.

-> null2() will get fails, because its have the disabled attribute. So its return sone value. not return Null