Selenium: Take screenshot on test failure

Going ahead on the theme of testing publicly available websites using selenium, in this blog I want to work out an example which touches on following points:

    •    Run Selenium WebDriver tests under TestNG
    •    Use the following best practices:
    ◦    Page Object Model
    ◦    UI Mapping
    ◦    Data Driven Testing
    ◦    And most importantly take screenshot on an event of test failure
Now to do all of the above I need a publicly available website that sounds interesting enough and devise testing around it. So here we go...

Test the DirectGov Council Tax Band website, given postcode, first line of address and an expected band.
The site that we are using is  http://www.voa.gov.uk/cti/InitS.asp
 

Setup Java project with Maven 

Now import the maven project in your favorite IDE. I am using Eclipse.

Since we are going to use selenium with testng instead of junit my pom.xml looks like following.

Test and Helper Class

Now that we have got a Java project set up, lets get cracking. Since I have already done my code before writing this blog, my final directory tree looks like following.

Let me add a bit of context around what is the role of each file in the directory tree above is. Later I will add more details about each of the relevant files.

• CTaxBandTest.java - This is the testng file that contains all the test cases just by the virtue of keyword 'test' in the file name.
• CTaxBandSearch.java - Page Object Model Class. The Page Object Design Pattern provides the followingadvantages.
• There is clean separation between test code and page specific code suchas locators (or their use if you’re using a UI map) and layout
• There is single repository for the services or operations offered by thepage rather than having these services scattered through out the tests.
• WebDriverManager.java - This class will manage the singleton WebDriver instance that will be used in our tests. The importance of this manager class will become relevant when we go through the details of how to get screenshot on test failure.
• ScreenShotOnFailure.java - Contains code to capture and store screenshot on event of test failure at correct location so that these screenshots is available via test reports.
• ui_mapping.properties - UI Mapping file. Contains all the UI locators in one file for ease of modification.

 

CTaxBandTest.java

In the test case above we have used various testng annotations. The important one is @Listeners which basically defines one or more of users classes, which implement some interfaces that TestNG provides, so that when TestNG raises certain events it will look for all “classes” which are basically looking for such events and call the respective event handlers in them. In this case we are using it to define handler for onTestFailure so that we can capture the screenshot and include it in testng report.
We are also using the @DataProvider annotation to make our test case data driven which basically means that we have more than 1 data set points to run through same test case.

WebDriverManager.java

This is a static helper class which manages the only Selenium WebDriver instance we are using for all test cases. This makes access to this webdriver instance very easy later on when we want to take a screenshot on event of test failure. 

CTaxBandSearch.java

This is the Page Object Model class which knows how to navigate the website page which we want to test. As you can see I have also made use of UI Mapping best practice here and get all locators from a properties file.

ScreenShotOnFailure.java

And lastly the listener class which will override the onTestFailure handler of testng and help us get the crucial screenshot when a test case fails.

We can get hold of the webdriver instance very easily since its now managed by a WebDriverManager class. Above class also demonstrates how to include the screenshot link in the test reports.

Run the test

Now that we have all the bits and pieces in place lets run our test case. You might have not noticed but I have deliberately included a council tax band incorrect in our @DataProvider which means that 1 test case will pass and 1 fails with a screenshot!

The reports are generated in target/surefire-reports/ directory and looking at the reports... hurray screenshots at last!!!

This has been kind of a long post, but I did want to touch on a few points in one go and glad that its out there now.