The pipeline
<p:declare-step xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
<p:output port="result"/>
<p:json-merge>
<p:with-input expand-text="false">
<p:inline content-type="application/json">{"key1" : "value1", "key2" : "value2"}</p:inline>
<p:inline content-type="application/json">{"key3" : "value3"}</p:inline>
<p:inline content-type="application/json">{"key4" : "value4"}</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="map" uri="http://www.w3.org/2005/xpath-functions"/>
<s:pattern>
<s:rule context="/">
<s:assert test="map:map">The document node is not 'map:map'.</s:assert>
<s:assert test="count(map:map/*)=4">Element 'map:map' does not have four children.</s:assert>
<s:assert test="count(map:map/map:string)=4">Element 'map:map' does not have four children 'map:string'.</s:assert>
<s:assert test="map:map/map:string[@key='key1']='value1'">Element 'string' with @key1 does not have text child 'value1'.</s:assert>
<s:assert test="map:map/map:string[@key='key2']='value2'">Element 'string' with @key2 does not have text child 'value2'.</s:assert>
<s:assert test="map:map/map:string[@key='key3']='value3'">Element 'string' with @key3 does not have text child 'value3'.</s:assert>
<s:assert test="map:map/map:string[@key='key4']='value4'">Element 'string' with @key4 does not have text child 'value4'.</s:assert>
</s:rule>
</s:pattern>
</s:schema>
