fix: Prevent generated metadata from being stored

src/ldp/auxiliary/LinkMetadataGenerator.ts

@@ -1,4 +1,5 @@
 import { namedNode } from '@rdfjs/data-model';
+import { SOLID_META } from '../../util/Vocabularies';
 import type { RepresentationMetadata } from '../representation/RepresentationMetadata';
 import type { AuxiliaryIdentifierStrategy } from './AuxiliaryIdentifierStrategy';
 import { MetadataGenerator } from './MetadataGenerator';
@@ -22,7 +23,9 @@ export class LinkMetadataGenerator extends MetadataGenerator {
   public async handle(metadata: RepresentationMetadata): Promise<void> {
     const identifier = { path: metadata.identifier.value };
     if (!this.identifierStrategy.isAuxiliaryIdentifier(identifier)) {
-      metadata.add(this.link, namedNode(this.identifierStrategy.getAuxiliaryIdentifier(identifier).path));
+      metadata.add(this.link,
+        namedNode(this.identifierStrategy.getAuxiliaryIdentifier(identifier).path),
+        SOLID_META.terms.ResponseMetadata);
     }
   }
 }

src/storage/DataAccessorBasedStore.ts

@@ -26,7 +26,18 @@ import {
 } from '../util/PathUtil';
 import { parseQuads } from '../util/QuadUtil';
 import { addResourceMetadata } from '../util/ResourceUtil';
-import { CONTENT_TYPE, DC, SOLID_HTTP, LDP, POSIX, PIM, RDF, VANN, XSD } from '../util/Vocabularies';
+import {
+  CONTENT_TYPE,
+  DC,
+  SOLID_HTTP,
+  LDP,
+  POSIX,
+  PIM,
+  RDF,
+  XSD,
+  SOLID_META,
+  PREFERRED_PREFIX_TERM,
+} from '../util/Vocabularies';
 import type { DataAccessor } from './accessors/DataAccessor';
 import type { ResourceStore } from './ResourceStore';
 
@@ -98,16 +109,23 @@ export class DataAccessorBasedStore implements ResourceStore {
       for await (const child of this.accessor.getChildren(identifier)) {
         if (!this.auxiliaryStrategy.isAuxiliaryIdentifier({ path: child.identifier.value })) {
           metadata.addQuads(child.quads());
-          metadata.add(LDP.terms.contains, child.identifier as NamedNode);
+          metadata.add(LDP.terms.contains, child.identifier as NamedNode, SOLID_META.terms.ResponseMetadata);
         }
       }
 
       // Generate a container representation from the metadata
-      const data = metadata.quads();
-      metadata.addQuad(DC.terms.namespace, VANN.terms.preferredNamespacePrefix, 'dc');
-      metadata.addQuad(LDP.terms.namespace, VANN.terms.preferredNamespacePrefix, 'ldp');
-      metadata.addQuad(POSIX.terms.namespace, VANN.terms.preferredNamespacePrefix, 'posix');
-      metadata.addQuad(XSD.terms.namespace, VANN.terms.preferredNamespacePrefix, 'xsd');
+      // All triples should be in the same graph for the data representation
+      const data = metadata.quads().map((triple): Quad => {
+        if (triple.graph.termType === 'DefaultGraph') {
+          return triple;
+        }
+        return DataFactory.quad(triple.subject, triple.predicate, triple.object);
+      });
+
+      metadata.addQuad(DC.terms.namespace, PREFERRED_PREFIX_TERM, 'dc', SOLID_META.terms.ResponseMetadata);
+      metadata.addQuad(LDP.terms.namespace, PREFERRED_PREFIX_TERM, 'ldp', SOLID_META.terms.ResponseMetadata);
+      metadata.addQuad(POSIX.terms.namespace, PREFERRED_PREFIX_TERM, 'posix', SOLID_META.terms.ResponseMetadata);
+      metadata.addQuad(XSD.terms.namespace, PREFERRED_PREFIX_TERM, 'xsd', SOLID_META.terms.ResponseMetadata);
       representation = new BasicRepresentation(data, metadata, INTERNAL_QUADS);
     } else {
       // Retrieve a document representation from the accessor
@@ -317,6 +335,11 @@ export class DataAccessorBasedStore implements ResourceStore {
       }
     }
 
+    // Remove all generated metadata to prevent it from being stored permanently
+    representation.metadata.removeQuads(
+      representation.metadata.quads(null, null, null, SOLID_META.terms.ResponseMetadata),
+    );
+
     await (isContainer ?
       this.accessor.writeContainer(identifier, representation.metadata) :
       this.accessor.writeDocument(identifier, representation.data, representation.metadata));

src/storage/accessors/FileDataAccessor.ts

@@ -15,7 +15,7 @@ import { joinFilePath, isContainerIdentifier } from '../../util/PathUtil';
 import { parseQuads, serializeQuads } from '../../util/QuadUtil';
 import { addResourceMetadata } from '../../util/ResourceUtil';
 import { toLiteral } from '../../util/TermUtil';
-import { CONTENT_TYPE, DC, LDP, POSIX, RDF, XSD } from '../../util/Vocabularies';
+import { CONTENT_TYPE, DC, LDP, POSIX, RDF, SOLID_META, XSD } from '../../util/Vocabularies';
 import type { FileIdentifierMapper, ResourceLink } from '../mapping/FileIdentifierMapper';
 import type { DataAccessor } from './DataAccessor';
 
@@ -319,10 +319,14 @@ export class FileDataAccessor implements DataAccessor {
    * @param stats - Stats of the file/directory corresponding to the resource.
    */
   private addPosixMetadata(metadata: RepresentationMetadata, stats: Stats): void {
-    metadata.add(DC.terms.modified, toLiteral(stats.mtime.toISOString(), XSD.terms.dateTime));
-    metadata.add(POSIX.terms.mtime, toLiteral(Math.floor(stats.mtime.getTime() / 1000), XSD.terms.integer));
+    metadata.add(DC.terms.modified,
+      toLiteral(stats.mtime.toISOString(), XSD.terms.dateTime),
+      SOLID_META.terms.ResponseMetadata);
+    metadata.add(POSIX.terms.mtime,
+      toLiteral(Math.floor(stats.mtime.getTime() / 1000), XSD.terms.integer),
+      SOLID_META.terms.ResponseMetadata);
     if (!stats.isDirectory()) {
-      metadata.add(POSIX.terms.size, toLiteral(stats.size, XSD.terms.integer));
+      metadata.add(POSIX.terms.size, toLiteral(stats.size, XSD.terms.integer), SOLID_META.terms.ResponseMetadata);
     }
   }
 

src/util/Vocabularies.ts

@@ -128,6 +128,11 @@ export const SOLID_HTTP = createUriAndTermNamespace('urn:npm:solid:community-ser
   'slug',
 );
 
+export const SOLID_META = createUriAndTermNamespace('urn:npm:solid:community-server:meta:',
+  // This identifier is used as graph for all metadata that is generated on the fly and should not be stored
+  'ResponseMetadata',
+);
+
 export const VANN = createUriAndTermNamespace('http://purl.org/vocab/vann/',
   'preferredNamespacePrefix',
 );