fix: too much recursion error for circular references

lib/Context.js

@@ -1,4 +1,6 @@
+import toNT from '@rdfjs/to-ntriples'
 import * as ns from './namespaces.js'
+import pathsToString from './pathsToString.js'
 import Report from './Report.js'
 import Result from './Result.js'
 
@@ -7,7 +9,9 @@ class Context {
     factory,
     focusNode,
     options = { debug: false, details: false },
+    processed = new Set(),
     report = new Report({ factory, options }),
+    results = new Map(),
     shape,
     value,
     valueOrNode,
@@ -17,7 +21,9 @@ class Context {
     this.factory = factory
     this.focusNode = focusNode
     this.options = options
+    this.processed = processed
     this.report = report
+    this.results = results
     this.shape = shape
     this.value = value
     this.valuePaths = valuePaths
@@ -38,7 +44,9 @@ class Context {
       factory: this.factory,
       focusNode,
       options: this.options,
+      processed: this.processed,
       report: child ? new Report({ factory: this.factory, options: this.options }) : this.report,
+      results: this.results,
       shape,
       value,
       valueOrNode,
@@ -47,15 +55,29 @@ class Context {
     })
   }
 
+  id ({ shape = this.shape } = {}) {
+    return `${toNT(shape.ptr.term)} - ${toNT(this.focusNode.term)} - ${pathsToString(this.valuePaths)}`
+  }
+
   result (args) {
-    this.report.results.push(new Result({
+    const result = new Result({
       factory: this.factory,
       focusNode: this.focusNode,
       shape: this.shape,
       value: this.value,
       valuePaths: this.valuePaths,
       ...args
-    }))
+    })
+
+    const id = this.id()
+
+    if (!this.results.has(id)) {
+      this.results.set(id, new Set([result]))
+    } else {
+      this.results.get(id).add(result)
+    }
+
+    this.report.results.push(result)
   }
 
   debug (constraintComponent, args) {

lib/Shape.js

@@ -64,6 +64,20 @@ class Shape {
   }
 
   async validate (context) {
+    const id = context.id({ shape: this })
+
+    if (context.processed.has(id)) {
+      if (context.results.has(id)) {
+        for (const result of context.results.get(id)) {
+          context.report.results.push(result)
+        }
+      }
+
+      return context
+    }
+
+    context.processed.add(id)
+
     return this.shapeValidator.validate(context)
   }
 }

lib/pathsToString.js

@@ -0,0 +1,19 @@
+import toNT from '@rdfjs/to-ntriples'
+
+function pathToString (path) {
+  if (!path) {
+    return '{}'
+  }
+
+  return `{${[...path.quads()].map(quad => toNT(quad)).join(' ')}}`
+}
+
+function pathsToString (paths) {
+  if (!paths) {
+    return '{}'
+  }
+
+  return `{${paths.map(path => pathToString(path)).join(' ')}}`
+}
+
+export default pathsToString

test/assets/custom/circular.ttl

@@ -0,0 +1,86 @@
+@prefix ex: <http://example.org/>.
+@prefix mf: <http://www.w3.org/2001/sw/DataAccess/tests/test-manifest#>.
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>.
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
+@prefix sh: <http://www.w3.org/ns/shacl#>.
+@prefix shn: <https://schemas.link/shacl-next#>.
+@prefix sht: <http://www.w3.org/ns/shacl-test#>.
+
+<> a mf:Manifest;
+  mf:entries (<circular>).
+
+<circular> a sht:Validate;
+  rdfs:label "Test of circular references";
+  mf:action [
+      sht:dataGraph <>;
+      sht:shapesGraph <>
+    ];
+  mf:result [ a sh:ValidationReport;
+      sh:conforms true;
+      sh:result [ a sh:ValidationResult;
+          sh:detail [ a sh:ValidationResult;
+              sh:detail [ a sh:ValidationResult;
+                  sh:focusNode ex:thing;
+                  sh:resultPath ex:hasPart;
+                  sh:resultSeverity shn:Trace;
+                  sh:sourceConstraintComponent shn:TraversalConstraintComponent;
+                  sh:sourceShape ex:HasPartShape;
+                  sh:value ex:part
+                ], [ a sh:ValidationResult;
+                  sh:focusNode ex:thing;
+                  sh:resultPath ex:hasPart;
+                  sh:resultSeverity shn:Debug;
+                  sh:sourceConstraintComponent sh:NodeConstraintComponent;
+                  sh:sourceShape ex:HasPartShape;
+                  sh:value ex:part
+                ];
+              sh:focusNode ex:part;
+              sh:resultPath ex:isPartOf;
+              sh:resultSeverity shn:Debug;
+              sh:sourceConstraintComponent sh:OrConstraintComponent;
+              sh:sourceShape ex:IsPartOfShape;
+              sh:value ex:thing
+            ], [ a sh:ValidationResult;
+              sh:focusNode ex:part;
+              sh:resultPath ex:isPartOf;
+              sh:resultSeverity shn:Trace;
+              sh:sourceConstraintComponent shn:TraversalConstraintComponent;
+              sh:sourceShape ex:IsPartOfShape;
+              sh:value ex:thing
+            ];
+          sh:focusNode ex:thing;
+          sh:resultPath ex:hasPart;
+          sh:resultSeverity shn:Debug;
+          sh:sourceConstraintComponent sh:NodeConstraintComponent;
+          sh:sourceShape ex:HasPartShape;
+          sh:value ex:part
+        ], [ a sh:ValidationResult;
+          sh:focusNode ex:thing;
+          sh:resultPath ex:hasPart;
+          sh:resultSeverity shn:Trace;
+          sh:sourceConstraintComponent shn:TraversalConstraintComponent;
+          sh:sourceShape ex:HasPartShape;
+          sh:value ex:part
+        ]
+    ].
+
+ex:part
+  ex:isPartOf ex:thing.
+
+ex:thing a ex:Thing;
+  ex:hasPart ex:part.
+
+ex:ThingShape a sh:NodeShape;
+  sh:targetClass ex:Thing;
+  sh:property ex:HasPartShape.
+
+ex:ThingPartShape a sh:NodeShape;
+  sh:property ex:IsPartOfShape.
+
+ex:IsPartOfShape
+  sh:or (ex:ThingShape);
+  sh:path ex:isPartOf.
+
+ex:HasPartShape
+  sh:node ex:ThingPartShape;
+  sh:path ex:hasPart.

test/assets/custom/manifest.ttl

@@ -5,6 +5,7 @@
   rdfs:label "Custom tests";
   mf:include
     <and-multi-list.ttl>,
+    <circular.ttl>,
     <deactivated-closed.ttl>,
     <or-multi-list.ttl>,
     <qualifiedValueShape.ttl>,