Xpath Assertion eases life when we have to validate if an object exists.
For ex:
Let's again take a shopping cart example.
1.Search for an item
2.Add selected item to shopping cart > now we want to verify if the Add cart button is available on the page.
Therefore we need to add a xpath assertion.
Below screen shot should give a clear idea & how an expression is built.
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Let's have a closer look at the Xpath Assertion.
Add a xpath Assertion :
1. Right Click on the HTTP Sampler > Assertions > Xpath Assertions.
Once you'ev added the Xpath Assertion, now we have to add appropriate values so that we can assert object or value.
1. Give a name to Xpath Assertion just like i have given not necessarily same.
2. XML Parsing Options - Check the Checkbox's against "Use Tidy(tolerant parser) & Quiet".
3. Xpath Assertion - contract the xpath & pass the xpath string within the Xpath Assertion.
For ex : I am validating to see if the button with id "bestAvailableTickets_LookForTicketsButton"" exists on that page.
I have left the "True if nothing matches" as unchecked as i want it to match.