I am trying to utilize SHACL-JS to access external JavaScript functions and perform constraint validation on an RDF graph. The reason for using external functions is I need to perform some complex mathematical operations, which cannot be performed directly within SHACL-SPARQL.
The shape graph I used is as follows:

PREFIX CSRO: <http://www.semanticweb.org/aagr657/ontologies/2023/9/CraneSpaceRepresentationOntology#> 
PREFIX LinkOnt: <http://purl.org/ConstructLinkOnt/LinkOnt#> 
PREFIX bot: <https://w3id.org/bot#> 
PREFIX expr: <https://w3id.org/express#>
PREFIX geo: <http://www.opengis.net/ont/geosparql#>
PREFIX geom: <http://rdf.bg/geometry.ttl#> 
PREFIX ifc: <https://standards.buildingsmart.org/IFC/DEV/IFC2x3/TC1/OWL#> 
PREFIX inst: <https://www.ugent.be/myAwesomeFirstBIMProject#> 
PREFIX owl: <http://www.w3.org/2002/07/owl#>
PREFIX sf: <http://www.opengis.net/ont/sf#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
PREFIX omg: <https://w3id.org/omg#> 
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX lbd: <https://linkedbuildingdata.org/LBD#>
PREFIX props: <http://lbd.arch.rwth-aachen.de/props#>
PREFIX unit: <http://qudt.org/vocab/unit/>
PREFIX IFC4-PSD: <https://www.linkedbuildingdata.net/IFC4-PSD#>
PREFIX smls: <https://w3id.org/def/smls-owl#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX fog: <https://w3id.org/fog#>
PREFIX vann: <http://purl.org/vocab/vann/>
PREFIX express: <https://w3id.org/express#>
PREFIX dce: <http://purl.org/dc/elements/1.1/>
PREFIX cc: <http://creativecommons.org/ns#>
PREFIX sh: <http://www.w3.org/ns/shacl#>

inst: 
     sh:declare [
     sh:prefix "inst";
     sh:namespace "https://www.ugent.be/myAwesomeFirstBIMProject#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "ifc";
     sh:namespace "https://standards.buildingsmart.org/IFC/DEV/IFC2x3/TC1/OWL#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "owl";
     sh:namespace "http://www.w3.org/2002/07/owl#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "LinkOnt";
     sh:namespace "http://purl.org/ConstructLinkOnt/LinkOnt#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "CSRO";
     sh:namespace "http://www.semanticweb.org/aagr657/ontologies/2023/9/CraneSpaceRepresentationOntology#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "bot";
     sh:namespace "https://w3id.org/bot#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "geo";
     sh:namespace "http://www.opengis.net/ont/geosparql#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "sf";
     sh:namespace "http://www.opengis.net/ont/sf#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "rdfs";
     sh:namespace "http://www.w3.org/2000/01/rdf-schema#"^^xsd:anyURI ;
     ];
     sh:declare [
     sh:prefix "rdf";
     sh:namespace "http://www.w3.org/1999/02/22-rdf-syntax-ns#"^^xsd:anyURI ;
     ].

inst:checkCollision
    rdf:type sh:JSFunction ;
    sh:parameter [
        sh:path inst:surface1;
        sh:datatype geo:wktLiteral;
    ];
    sh:parameter [
        sh:path inst:surface2;
        sh:datatype geo:wktLiteral;
    ];
    sh:returnType xsd:boolean;
    sh:jsLibrary [ sh:jsLibraryURL "http://localhost:8000/Constraint_Checking_Functions.js"^^xsd:anyURI ] ;
    sh:jsFunctionName "checkEquality" .

inst:boundingBoxIntersectionDetection
    rdf:type sh:NodeShape ;
    sh:target [
            rdf:type sh:SPARQLTarget ; 
            sh:prefixes inst: ; 
            sh:select """
                SELECT $this
                WHERE {
                $this rdf:type ifc:IfcTask;
                      LinkOnt:TaskLevel LinkOnt:SubActivity.     
                }
            """;
        ];
    sh:sparql [
        rdf:type sh:SPARQLConstraint ;
        sh:message "Space constraint is violated" ;
        sh:prefixes inst: ;
        sh:select"""
            SELECT $this
            WHERE {
                $this LinkOnt:HasResource ?resource.
                ?resource rdf:type LinkOnt:Resource;
                      LinkOnt:ResourceType LinkOnt:Equipment; 
                      owl:sameAs ?crane.
                ?crane rdf:type CSRO:CrawlerCrane;
                       CSRO:hasComponent ?craneComponent.
                ?craneComponent CSRO:hasBoundingBox ?polyhedralsurface1.
                ?polyhedralsurface1 rdf:type sf:PolyhedralSurface;
                           geo:asWKT ?surfaceValue1.
                ?siteElement rdf:type bot:Element;
                         CSRO:hasBoundingBox ?polyhedralsurface2.
                ?polyhedralsurface2 rdf:type sf:PolyhedralSurface;
                            geo:asWKT ?surfaceValue2.
                BIND (inst:checkCollision(?surfaceValue1, ?surfaceValue2) AS ?result).
                FILTER (?result = "true")
            }
            """;
        ].

This is a sample shape, which I am using just for testing purpose. The objective of this shape is just to validate that no two bounding boxes in the RDF data are equal (as I said, this is just for testing purpose, just to get the approach right. I’ll be developing shape and JS functions for more complex operations).
The JS function checkEquality is as follows:

function checkEQuality ($surfaceValue1, $surfaceValue2) {
    if ($surfaceValue1 = $surfaceValue2) {
        return "true";
    }
}

The link to the datagraph is (sharing the link as it is a large file) –
https://drive.google.com/file/d/1Dz8M0obbajLOWvy8RYGzXgL3LSRsVEHl/view?usp=sharing

For validation, I used two approaches – One using PySHACL and the Second using Apache Jena SHACl.

1. PySHACL – The code used for validation is as follows :

from pyshacl import validate
conforms, v_graph, v_text = validate(data_graph, shacl_graph=shape_graph, ont_graph = None, advanced = True, inference='rdfs', js=True)

Where, the data graph and shape_graph point to the turtle files containing the data graph and shape graph respectively.
2. Apache Jena CLI –

shacl validate --shapes=path_to_shape_graph_file --data=path_to_data_graph_file

However, using both the approaches, the validation result always comes to be true.
The validation result for PySHACL is as follows –

True
Validation Report
Conforms: True

The validation result for Apache jena is as follows –

[ rdf:type     sh:ValidationReport;
  sh:conforms  true
] .

The problem is, I am not sure if the shape is actually accessing the external function or not. This is because, for the FILTER statement in the SPARQL constraint, whatever value of the string I use in FILTER (?result = "true") in place of “true”, the validation result is always true, which should not be the case. I think there is something wrong with the way the JS function is being accessed and the arguments are being passed.

Could anyone please suggest if what I am trying is the right way of accessing the JavaScript functions from SHACL_JS and passing the arguments? What changes should be made to the shape so that I can pass the arguments to the external JS function and use the computation results for constraint checking. I searched a lot online, but not much of the information is available, other than the official W3C SHACL-JS documentation.
(I am not sure about Apache Jena CLI, but PySHACL supports SHACL-JS. So I think support of SHACL-JS should not be a problem).

Thanks.