The pipeline
<p:declare-step xmlns:c="http://www.w3.org/ns/xproc-step" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:archive-manifest override-content-types="[['^ab-doc\.xml$' , 'application/tester+xml'], ['\.xml$', 'application/test+xml']]">
<p:with-input href="../documents/ab-doc.zip"/>
</p:archive-manifest>
<p:identity>
<p:with-input>
<result>{string(/c:archive/c:entry[@name='ab-doc.xml']/@content-type)}</result>
</p:with-input>
</p:identity>
</p:declare-step>
Schematron validation
<s:schema xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:ns prefix="c" uri="http://www.w3.org/ns/xproc-step"/>
<s:pattern>
<s:rule context="/">
<s:assert test="result">The root element is not 'result'.</s:assert>
<s:assert test="result/text()='application/tester+xml'">Text content of 'result' is not 'application/tester+xml'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
