Handling Assertions in TestNG

Question

How can I continue the test execution in TestNG if an assertion fails? How can I report the failure in the HTML report of TestNG?

When I run the following code, the lines after assertion are executed but in the reports the assertion failure is not listed:

@Test
public void googleSearch(){
    driver.get("http://www.google.co.in/");
    System.out.println(" ---------- Start -------------");

    try {
        Assert.assertTrue(driver.findElement(By.xpath("xyz")).isDisplayed(), "unable to find the link");
    } catch (Throwable t) {
        System.out.println("Error");
    }
    System.out.println(" ---------- End -------------");
}

Answer 1

You can use this code in catch block: -

org.testng.Assert.fail("expected and actual result do not match");

Lets take example of following code : -

String expectedtitle="xyz";
String actualtitle="xywz";
try {
    Assert.assertEquals(expectedtitle, actualtitle);
} catch(Throwable t) {              
    org.testng.Assert.fail("expected and actual result do not match");      
}

Answer 2

If you catch the AssertionError, TestNG can't see it.

Answer 3

Agreed, continuing the test after a failure is not best practice. Use after*Methods() for stuff.

Specifically for logging of test (configuration) start and end however, don't do it in the test class at all - create a listener, and do the logging from the listener.

You could extend TestListenerAdapter and implement all methods that it dictates:

http://testng.org/javadoc/org/testng/TestListenerAdapter.html

public class YourTestResultMonitor extends TestListenerAdapter {
    *snip*
}

Answer 4

Rather than catching assertion errors, in your test design preferably try to avoid the need to continue tests after they fail.

• If you need to close, disconnect or otherwise free up resources used by the test, do that in @AfterMethod.
• If you want to test multiple independent things and verify which of them pass and which fail, put them into separate tests. In case you have multiple tests that share a similar setup (e.g. navigate to a certain point in your application), move the setup into @BeforeMethod.
• If you are testing multiple conditions that depend on each other, the test should exit as soon as the first failure is encountered. Because of the dependency, you would otherwise be likely to see false negatives in later asserts.

In your example:

@BeforeMethod
public void openPage() {
    driver.get("http://www.google.co.in/");
    System.out.println(" ---------- Start -------------");
}

@Test
public void googleSearchThis(){
    Assert.assertTrue(driver.findElement(By.xpath("xyz")).isDisplayed(), "unable to find the link");
}

@Test
public void googleSearchThat(){
    // assert for other things you want to test on the same page
}

@AfterMethod
public void closePage() {
    System.out.println(" ---------- End -------------");
}

Answer 5

I suggest to use soft assertions, which are provided in TestNG natively

package automation.tests;

import org.testng.asserts.Assertion;
import org.testng.asserts.SoftAssert;

public class MyTest {
  private Assertion hardAssert = new Assertion();
  private SoftAssert softAssert = new SoftAssert();
}

@Test
public void testForSoftAssertionFailure() {
  softAssert.assertTrue(false);
  softAssert.assertEquals(1, 2);
  softAssert.assertAll();
}

Answer 6

Since you have caught the error, this will not fail. I recreated the situation as following. This did not fail. But a Throwable is thrown. Error is printed.

public class TNG {
    WebDriver driver;

    @Test
    public void googleSearch(){
        System.setProperty("webdriver.chrome.driver", "path to web driver");
        driver = new ChromeDriver();
        driver.get("http://www.google.co.in/");
        System.out.println(" ---------- Start -------------");      
    try {
         Assert.assertTrue(driver.findElement(By.xpath("xyz")).isDisplayed(), "unable to find the link");

    } catch (Throwable t) {
        System.out.println("Error");
    }
    System.out.println(" ---------- End -------------");
  }

   @Test
   public void anotherTest(){
      System.out.println("another test");
   }
}

Following is the result from the execution of the test.

another test
Starting ChromeDriver 2.30.477700 (0057494ad8732195794a7b32078424f92a5fce41) on port 43423
Only local connections are allowed.
Jul 20, 2017 5:55:33 PM org.openqa.selenium.remote.ProtocolHandshake createSession
INFO: Detected dialect: OSS
---------- Start -------------
Error
---------- End -------------
PASSED: anotherTest
PASSED: googleSearch

===============================================
Default test
Tests run: 2, Failures: 0, Skips: 0
===============================================


===============================================
Default suite
Total tests run: 2, Failures: 0, Skips: 0
===============================================

And if you want to continue test execution even though some tests failed , you can simply write methods with @Test annotation like the anotherTest() method that I have created. But you can not guarantee the order of the test execution. In here above anotherTest() has been executed first.