There is only one powerful tag to test XFA data:

<!-- Tag to compare XFA data: -->

<haveSameXFAData />

The result of the XPath expression has to be the same for both PDF documents:

<testcase name="haveSameXFAData_ResulttypeNode">
  <assertThat testDocument="test/test.pdf"
              masterDocument="master/master.pdf"
  >
    <haveSameXFAData>
      <matchingXPath expr="//default:pageSet" 
                     withResultType="NODE" 
                     defaultNamespace="http://www.xfa.org/schema/xfa-template/2.6/" 
      />
    </haveSameXFAData>
  </assertThat>
</testcase>

As you can see in the example the type of the expected result has to be specified. Possible result types for the attribute withResultType:

<!-- Result types for XPath-processing:  -->

withResultType="BOOLEAN"
withResultType="NUMBER"
withResultType="NODE"
withResultType="NODESET"
withResultType="STRING"

The XPath-expressions may contain XPath functions:

<testcase name="haveSameXFAData_ResulttypeBoolean">
  <assertThat testDocument="test/test.pdf"
              masterDocument="master/master.pdf"
  >
    <haveSameXFAData>
      <matchingXPath expr="count(//default:field) = 3" 
                     withResultType="BOOLEAN" 
                     defaultNamespace="http://www.xfa.org/schema/xfa-template/2.6/" 
      />
    </haveSameXFAData>
  </assertThat>
</testcase>

Tests with an expected result type BOOLEAN are a problem because PDFUnit can't differentiate between “not found ” and “false”.

A detailed description of how to work with XPath in PDFUnit can be found in chapter 8: “Using XPath”.

Be careful using the default namespace. It has to be declared in the attribute <haveSameXFAData />. (Because you can declare namespaces multiple times it could be ambiguous to detect the default namespace automatically.)

You can use the tag <matchingXPath /> more than once in a test. But it would be better to split the following test:

<!-- 
  Test with multiple XPath expressions.
  
  It is not recommended to create tests in this way.
  But PDFUnit has to ensure that it works.
-->
<testcase name="haveSameXFAData_MultipleDefaultNamespaces">
  <assertThat testDocument="test/test.pdf"
              masterDocument="master/master.pdf"
  >
    <haveSameXFAData>
      <matchingXPath expr="//default:agent/@name[.='designer']" 
                     withResultType="BOOLEAN"
                     defaultNamespace="http://www.xfa.org/schema/xci/2.6/" 
      />
      <matchingXPath expr="//default:subform/@name[.='movie']" 
                     withResultType="BOOLEAN"
                     defaultNamespace="http://www.xfa.org/schema/xfa-template/2.6/" 
      />
      <matchingXPath expr="//default:locale/@name[.='nl_BE']" 
                     withResultType="BOOLEAN"
                     defaultNamespace="http://www.xfa.org/schema/xfa-locale-set/2.7/" 
      />
    </haveSameXFAData>
  </assertThat>
</testcase>