• “Response Assertion“: the response assertion control panel lets you add pattern strings to be compared against various fields of the response
• “XPath Assertion“: the XPath Assertion tests a document for well formedness, has the option of validating against a DTD, or putting the document through JTidy and testing for an XPath (if that XPath exists, the Assertion is true)
• “HMTL Assertion“: the HTML Assertion allows the user to check the HTML syntax of the response data using JTidy.
• “XML Assertion“: tests that the response data consists of a formally correct XML document; it does not validate the XML based on a DTD or schema or do any further validation.
• “Compare Assertion“: can be used to compare sample results within its scope; either the contents or the elapsed time can be compared, and the contents can be filtered before comparison.
  Compare Assertion MUST NOT BE USED during load test as it consumes a lot of resources (memory and CPU). Use it only for either functional testing or during Test Plan debugging and Validation.
• “Size Assertion“: verifies that each response contains the right number of bytes in it; you can specify that the size be equal to,
  greater than, less than, or not equal to a given number of bytes

 

How much do assertions consume in terms of CPU and memory ?

If the test that your are using is a long running test or makes a very large number of requests you may encounter unexpected failures related to “out of memory” errors or similar.

In terms of resources the HMTL Assertion, XML Assertion or Compare Assertion consume a lot of resources so is a good idea to avoid using those in long running tests. The other assertions does not have a very bad impact on the resources so they can be used without a problem.

 

Which is the scope to which the assertions apply ?

There are 3 cases related to which scope an assertion applies to:

1. applies to all the child requests

 

2. applies to all the sibling requests

 

3. applies only to one specific request

 

How to use a “Response Assertion” in JMeter ?

Response Assertion is one of the most widely used assertion as it allows to verify the content of the response, status code or headers.

It can be configured to verify:

• the different segments of the response like text (response body)
• the document type like pdf, doc etc
• the headers
• the response code (2xx, 4xx)
• response message (description of code) and response headers
• tests the response against a pattern string which can be a plain text or a Perl5 regular expression; the specified pattern is matched against the selected segment of the response

 

Let’s start by adding a response assertion that expects that the response code is 200.

 

We will now add another assertion that expects that the text “wikipedia” is present in the response of the server.

 

 

Running the script will show that that the request succeeded without any problem.

 

Now we will change the text of the second assertion to “dummy_text_inexistent” and run the test again.

In the next tutorials we will show you how to use the rest of the assertions that are supported in JMeter.