Helper Wizards for Request Matching and Dynamic Response Creation – BlazeMeter

You can specify requests matcher conditions for transactions. If a user sends a request that matches your request condition, a custom response is rendered. In the request body matcher, you can define conditions on the request of various types such as XML, JSON, RegEx, matches XPath, matches JSON Path and so on.

The help wizards for XPath and JSON Path help you generate XPaths and JSON Paths for request matchers in a transaction so you don't have to enter the path manually. You just specify what type of value to match in tree-based selection fields and the path is generated for you.

The help wizard for responses helps you create dynamic values (Magic Strings) in the response content. With magic strings, the information is pulled from the request and rendered on the response so you do not have to worry about entering the syntax manually.

Add a Request Matcher Helper to an Existing Transaction
Adding Multiple Request Matchers
Add Dynamic Values to Responses
Best Practices for XML Content in Request and Response Wizard

Add a Request Matcher Helper to an Existing Transaction

Follow these steps:

Go to Mock Services tab and click Asset Catalog.
In the Transactions tab, expand an existing transaction.
In the Request Matcher section, click the Body tab.
Click + to define a body matcher.
Select matches XPath or matches JSON Path.

Use the Selection Wizard to define paths.

Click Selection Wizard.
Paste your XML in the Sample XML / Sample JSON text field.
A tree-based selector is generated.
Note: If you are editing transactions created from a RR-pair import, sample content is automatically taken from the Equals XML or Equals JSON body matchers. The wizard throws an error when the XML is invalid and if it does not follow standards.
Select the checkboxes of one or more nodes for which you want to generate an XPath or JSON Path.
The Match Value column displays sample values that are present in the sample XML. You can change the value if you want to broaden the matching logic.
From the Match Type dropdown, select one of two options:
1. Specific - matches the exact value that you provide in the Match Value text field.
2. Anything - verifies only the element's existence in your request. When you select Anything, the wizard disables the Match Value field.
Click Select to confirm.
The wizard generates an XPath / JSON Path for the matching logic.

For XPath, if your request XML has a namespace defined, the namespace URL is needed, and it is automatically extracted and populated in the wizard. You don't have to specify the URLs manually. If there are any namespace prefixes, the wizard automatically imports and lists it on the right side of the matcher.

Adding Multiple Request Matchers

You can add more than one request matcher and the request has to pass all the matching conditions to be considered as a match.
The sample XML/JSON that is used to display the tree just needs to be entered in the first matcher. Once done, it is carried over to the subsequent ones so you don't have to paste it again for a new matcher.
Any change in the sample XML/JSON will be reflected in the other matchers but it does not update the XPaths and JSON Paths already generated.
You have to select the wizard to change your selection after updating your sample XML/JSON.

Add Dynamic Values to Responses

The ‘Edit Wizard’ helps you create dynamic values (Magic Strings) in the response content. Magic strings are basically references to information/data from an incoming request that will be replaced with actual values in the response from the service. The wizard switches automatically between XPath and JSON path based on the type of request body. For all other http related entities, the wizard will generate its appropriate magic strings syntax of the request data.

Follow these steps:

Go to Mock Services tab and click Asset Catalog.
In the Transactions tab, expand an existing transaction.
In the Response section, click the Body tab.
Type or paste your response content in the text area.
If the content is a valid JSON or XML, an Edit Wizard link shows on the right.
Click the Edit Wizard link.
A pop-up window with the response content that you entered in the text area shows. The text field contains the original values you entered and an Expression button next to each field to set a dynamic value on that field.
Click the Expression button.
A detailed subsection displays all the request information that was found in the transaction. This includes Request Body, Request Query Parameters, Request Headers, Request Cookies and Common Parameters.
Map the request information to the appropriate fields.
Click Save. The original response in the text area is replaced and the magic strings that were generated based on your selection are used.