The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:replace match="/">
<p:with-input port="source">
<p:inline document-properties="map{'serialization':map{'indent': true()}, 'bogus-prop':'bogus'}">
<doc/>
</p:inline>
</p:with-input>
<p:with-input port="replacement">
<p:inline content-type="text/plain">Some text.</p:inline>
</p:with-input>
</p:replace>
<p:cast-content-type content-type="application/xml">
<p:with-input select="p:document-properties(.)"/>
</p:cast-content-type>
</p:declare-step>
Schematron validation
<s:schema xmlns="http://www.w3.org/1999/xhtml" xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:ns prefix="j" uri="http://www.w3.org/2005/xpath-functions"/>
<s:pattern>
<s:rule context="/">
<s:assert test="/j:map">Root element is not 'j:map'.</s:assert>
<s:assert test="/j:map/j:string[@key='bogus-prop']">There is no property 'bogus-prop'.</s:assert>
<s:assert test="/j:map/j:string[@key='bogus-prop']/text()='bogus'">Value of property is not 'bogus'.</s:assert>
<s:assert test="not(j:map/*[@key='serialization'])">There should be no property 'serialization'</s:assert>
<s:assert test="/j:map/j:string[@key='content-type']='text/plain'">Property 'content-type' is not 'text/plain'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
