The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:compress format="gzip">
<p:with-input>
<p:inline document-properties="map{'base-uri' : 'http://base.uri/doc', 'additional' : 'bogus', 'serialization' : map{'indent' : true()} }">
<doc/>
</p:inline>
</p:with-input>
</p:compress>
<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="json" uri="http://www.w3.org/2005/xpath-functions"/>
<s:pattern>
<s:rule context="/">
<s:assert test="json:map">The document root is not 'json:map'.</s:assert>
<s:assert test="json:map/json:string[@key='base-uri']/text()='http://base.uri/doc'">Property 'base-uri' is not 'http://base.uri/doc'.</s:assert>
<s:assert test="json:map/json:string[@key='additional']/text()='bogus'">Property 'additional' is not 'bogus'.</s:assert>
<s:assert test="not(json:map/json:string[@key='serialization'])">There should be no property 'serialization'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
