Test XS0038 is raised, if @test is missing on p:if
Test ab-if-001.xml is expected to fail with error code err:XS0038.
<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:output port="result">
   <p:identity>
      <p:with-input>
         <doc1/>
      </p:with-input>
   </p:identity>
   <p:if>
      <p:identity/>
   </p:if>
</p:declare-step>
New tests