Functional Testing with JMeter
JMeter is a 100% pure Java desktop application. JMeter is found to be very useful and convenient in support of functional testing. Although JMeter is known more as a performance testing tool, functional testing elements can be integrated within the Test Plan, which was originally designed to support load testing. Many other load-testing tools provide little or none of this feature, restricting themselves to performance-testing purposes. Besides integrating functional-testing elements along with load-testing elements in the Test Plan, you can also create a Test Plan that runs these exclusively. In other words, aside from creating a Load Test Plan, JMeter also allows you to create a Functional Test Plan. This flexibility is certainly resource-efficient for the testing project.
In this article by Emily H. Halili, we will give you a walkthrough on how to create a Test Plan as we incorporate and/or configure JMeter elements to support functional testing.
Preparing for Functional Testing
However, to compensate for these shortcomings, JMeter allows the tester to create assertions based on the tags and text of the page as the HTML file is received by the client. With some knowledge of HTML tags, you can test and verify any elements as you would expect them in the browser.
It is unnecessary to select a specific workload time to perform a functional test. In fact, the application you want to test may even reside locally, with your own machine acting as the "localhost" server for your web application. For this article, we will limit ourselves to selected functional aspects of the page that we seek to verify or assert.
Using JMeter Components
We will create a Test Plan in order to demonstrate how we can configure the Test Plan to include functional testing capabilities. The modified Test Plan will include these scenarios:
1. Create Account—New Visitor creating an Account
2. Login User—User logging in to an Account
Following these scenarios, we will simulate various entries and form submission as a request to a page is made, while checking the correct page response to these user entries. We will add assertions to the samples following these scenarios to verify the 'correctness' of a requested page. In this manner, we can see if the pages responded correctly to invalid data. For example, we would like to check that the page responded with the correct warning message when a user enters an invalid password, or whether a request returns the correct page.