SoapUI / REST / JSON / variable namespaces

As a developer of large Web applications, I'm used to relying on a few proven test strategies:

• Unit tests with JUnit / Cobertura and DOH / JSCoverage;
• Functional and Integration tests with Selenium 2.

When I joined my current development team to work on the project TradeInsight, I was introduced to SoapUI for the functional tests. I like it's ability to convert JSON to XML, enabling then the writing of XPath match assertions.

There's one little caveat related to the conversion and the XPath assertions:

• When the server response contains a single JSON object, the conversion introduce a namespace into the generated XML.
• And this namespace depends on the server address.

The following figures show the original JSON response and its conversion to XML with the inferred namespace.

JSON response produced by a REST service.

Transformation into a XML payload with an inferred namespace.

This automatic mapping to namespace server dependent does not allow to write server-agnostic code if you follow the suggested solution!

The following figures show a XPath match expression as documented in the SoapUI training materials. Sadly, running it against an XML with a namespace, this error is reported:

XPathContains assertion failed for path [//startDate/text()] : Exception missing content for xpath [//startDate/text()] in Response.

Simple XPath expression with the corresponding error message.

Corrected XPath expression as suggested, now server dependent :(

 A simple solution consists in replacing the specified namespace with the meta-character '*', which match any namespace. As all elements of the XML document are under the scope of the inferred namespace, it's important to prefix all nodes of the XPath expression with '*:', as illustrated by the following figure.

Use of the '*' prefix to produce assertion server independent.

I hope this helps.

A+, Dom