The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:json-merge key="concat('label-',$p:index)">
<p:with-input expand-text="false">
<p:inline content-type="application/json">{"key1" : "value1"}</p:inline>
<p:inline content-type="application/json">[1, 2]</p:inline>
<p:inline content-type="text/plain">This is a text document.</p:inline>
<p:inline>
<xml/>
</p:inline>
<p:inline content-type="text/html">
<html/>
</p:inline>
</p:with-input>
</p:json-merge>
<p:cast-content-type content-type="application/xml"/>
</p:declare-step>
Schematron validation
<s:schema xmlns:s="http://purl.oclc.org/dsdl/schematron" queryBinding="xslt2">
<s:ns prefix="fn" uri="http://www.w3.org/2005/xpath-functions"/>
<s:pattern>
<s:rule context="/">
<s:assert test="fn:map">The document node is not 'fn:map'.</s:assert>
<s:assert test="count(fn:map/*)=5">Document does not have five children.</s:assert>
</s:rule>
<s:rule context="/fn:map/*[1]">
<s:assert test="local-name(.)='string'">Local name of child element 1 is not 'string'.</s:assert>
<s:assert test="./@key='key1'">Child element 1 does not have @key with 'key1'.</s:assert>
<s:assert test="./text()='value1'">Child element 1 does not have text child 'value1'.</s:assert>
</s:rule>
<s:rule context="/fn:map/*[2]">
<s:assert test="local-name(.)='array'">Local name of child element 2 is not 'array'.</s:assert>
<s:assert test="./@key='label-2'">Child element 2 does not have @key with 'label-2'.</s:assert>
<s:assert test="./fn:number[1]='1'">Child element 2 does not have a child 'fn:number' with '1'.</s:assert>
<s:assert test="./fn:number[2]='2'">Child element 2 does not have a child 'fn:number' with '2'.</s:assert>
</s:rule>
<s:rule context="/fn:map/*[3]">
<s:assert test="local-name(.)='string'">Local name of child element 3 is not 'string'.</s:assert>
<s:assert test="./@key='label-3'">Child element 3 does not have @key with 'label-3'.</s:assert>
<s:assert test="./text()='This is a text document.'">Child element 3 does not have text child with 'This is a text document'.</s:assert>
</s:rule>
<s:rule context="/fn:map/*[4]">
<s:assert test="local-name(.)='string'">Local name of child element 4 is not 'string'.</s:assert>
<s:assert test="./@key='label-4'">Child element 4 does not have @key with 'label-4'.</s:assert>
<s:assert test="./text()='<xml/>'">Child element 4 does not have text child with '<xml/>'.</s:assert>
</s:rule>
<s:rule context="/fn:map/*[5]">
<s:assert test="local-name(.)='string'">Local name of child element 5 is not 'string'.</s:assert>
<s:assert test="./@key='label-5'">Child element 5 does not have @key with 'label-5'.</s:assert>
<s:assert test="starts-with(./text(), '<html')">Child element 5 does not have text child with '<html/>'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
