feat: store turtle prefixes in metadata when parsing

build: correct package-lock file

package.json

@@ -134,7 +134,7 @@
     "pump": "^3.0.0",
     "punycode": "^2.1.1",
     "rdf-dereference": "^2.0.0",
-    "rdf-parse": "^2.0.0",
+    "rdf-parse": "^2.1.0",
     "rdf-serialize": "^2.0.0",
     "rdf-terms": "^1.7.1",
     "sparqlalgebrajs": "^4.0.2",

src/storage/conversion/RdfToQuadConverter.ts

@@ -1,10 +1,13 @@
 import { PassThrough } from 'stream';
+import type { NamedNode } from '@rdfjs/types';
 import rdfParser from 'rdf-parse';
 import { BasicRepresentation } from '../../http/representation/BasicRepresentation';
 import type { Representation } from '../../http/representation/Representation';
+import { RepresentationMetadata } from '../../http/representation/RepresentationMetadata';
 import { INTERNAL_QUADS } from '../../util/ContentTypes';
 import { BadRequestHttpError } from '../../util/errors/BadRequestHttpError';
 import { pipeSafely } from '../../util/StreamUtil';
+import { PREFERRED_PREFIX_TERM, SOLID_META } from '../../util/Vocabularies';
 import { BaseTypedRepresentationConverter } from './BaseTypedRepresentationConverter';
 import type { RepresentationConverterArgs } from './RepresentationConverter';
 
@@ -20,13 +23,21 @@ export class RdfToQuadConverter extends BaseTypedRepresentationConverter {
   }
 
   public async handle({ representation, identifier }: RepresentationConverterArgs): Promise<Representation> {
+    const newMetadata = new RepresentationMetadata(representation.metadata, INTERNAL_QUADS);
     const rawQuads = rdfParser.parse(representation.data, {
       contentType: representation.metadata.contentType!,
       baseIRI: identifier.path,
-    });
+    })
+      // This works only for those cases where the data stream has been completely read before accessing the metadata.
+      // Eg. the PATCH operation, which is the main case why we store the prefixes in metadata here if there are any.
+      // See also https://github.com/CommunitySolidServer/CommunitySolidServer/issues/126
+      .on('prefix', (prefix, iri: NamedNode): void => {
+        newMetadata.addQuad(iri.value, PREFERRED_PREFIX_TERM, prefix, SOLID_META.terms.ResponseMetadata);
+      });
+
     const pass = new PassThrough({ objectMode: true });
     const data = pipeSafely(rawQuads, pass, (error): Error => new BadRequestHttpError(error.message));
 
-    return new BasicRepresentation(data, representation.metadata, INTERNAL_QUADS);
+    return new BasicRepresentation(data, newMetadata);
   }
 }

test/integration/LdpHandlerWithoutAuth.test.ts

@@ -1,5 +1,6 @@
 import { createReadStream } from 'fs';
 import fetch from 'cross-fetch';
+import type { Quad } from 'n3';
 import { DataFactory, Parser, Store } from 'n3';
 import { joinFilePath, PIM, RDF } from '../../src/';
 import type { App } from '../../src/';
@@ -11,7 +12,8 @@ import {
   getPresetConfigPath,
   getTestConfigPath,
   getTestFolder,
-  instantiateFromConfig, removeFolder,
+  instantiateFromConfig,
+  removeFolder,
 } from './Config';
 const { literal, namedNode, quad } = DataFactory;
 
@@ -396,4 +398,70 @@ describe.each(stores)('An LDP handler allowing all requests %s', (name, { storeC
     const response = await fetch(baseUrl, { method: 'PATCH', headers: { 'content-type': 'text/plain' }, body: 'abc' });
     expect(response.status).toBe(415);
   });
+
+  it('maintains prefixes after PATCH operations.', async(): Promise<void> => {
+    // POST
+    const body = [ '@prefix test: <http://test.com/>.',
+      'test:s1 test:p1 test:o1.',
+      'test:s2 test:p2 test:o2.' ].join('\n');
+    let response = await postResource(baseUrl, { contentType: 'text/turtle', body });
+    const documentUrl = response.headers.get('location')!;
+
+    // PATCH
+    const query = [ 'PREFIX test: <http://test.com/>',
+      'DELETE { test:s1 test:p1 test:o1 }',
+      'INSERT { test:s3 test:p3 test:o3. test:s4 test:p4 test:o4 }',
+      'WHERE {}',
+    ].join('\n');
+    await patchResource(documentUrl, query, true);
+
+    // GET
+    response = await getResource(documentUrl);
+    const parser = new Parser();
+    const quads: Quad[] = [];
+    let prefixes: any = {};
+    const text = await response.clone().text();
+    const promise = new Promise<void>((resolve, reject): void => {
+      parser.parse(text, (error, aQuad, prefixHash): any => {
+        if (aQuad) {
+          quads.push(aQuad);
+        }
+        if (!aQuad) {
+          prefixes = prefixHash;
+          resolve();
+        }
+        if (error) {
+          reject(error);
+        }
+      });
+    });
+
+    await promise;
+
+    const expected = [
+      quad(
+        namedNode('http://test.com/s2'),
+        namedNode('http://test.com/p2'),
+        namedNode('http://test.com/o2'),
+      ),
+      quad(
+        namedNode('http://test.com/s3'),
+        namedNode('http://test.com/p3'),
+        namedNode('http://test.com/o3'),
+      ),
+      quad(
+        namedNode('http://test.com/s4'),
+        namedNode('http://test.com/p4'),
+        namedNode('http://test.com/o4'),
+      ),
+    ];
+    await expectQuads(response, expected, true);
+    expect(prefixes).toEqual({
+      test: 'http://test.com/',
+    });
+    expect(quads).toHaveLength(3);
+
+    // DELETE
+    expect(await deleteResource(documentUrl)).toBeUndefined();
+  });
 });

test/unit/storage/conversion/RdfToQuadConverter.test.ts

@@ -3,6 +3,7 @@ import { Readable } from 'stream';
 import arrayifyStream from 'arrayify-stream';
 import { DataFactory } from 'n3';
 import rdfParser from 'rdf-parse';
+import { PREFERRED_PREFIX_TERM, SOLID_META } from '../../../../src';
 import { BasicRepresentation } from '../../../../src/http/representation/BasicRepresentation';
 import type { Representation } from '../../../../src/http/representation/Representation';
 import { RepresentationMetadata } from '../../../../src/http/representation/RepresentationMetadata';
@@ -11,7 +12,7 @@ import type { ResourceIdentifier } from '../../../../src/http/representation/Res
 import { RdfToQuadConverter } from '../../../../src/storage/conversion/RdfToQuadConverter';
 import { INTERNAL_QUADS } from '../../../../src/util/ContentTypes';
 import { BadRequestHttpError } from '../../../../src/util/errors/BadRequestHttpError';
-const { namedNode, triple } = DataFactory;
+const { namedNode, triple, literal, quad } = DataFactory;
 
 describe('A RdfToQuadConverter', (): void => {
   const converter = new RdfToQuadConverter();
@@ -63,6 +64,30 @@ describe('A RdfToQuadConverter', (): void => {
     ) ]);
   });
 
+  it('emits on prefixes when converting turtle to quads.', async(): Promise<void> => {
+    const id: ResourceIdentifier = { path: 'http://example.com/' };
+    const metadata = new RepresentationMetadata('text/turtle');
+    const representation = new BasicRepresentation(`
+      @prefix foaf: <http://xmlns.com/foaf/0.1/> .
+
+      <http://test.com/s> a foaf:Person.
+    `
+    , metadata);
+    const preferences: RepresentationPreferences = { type: { [INTERNAL_QUADS]: 1 }};
+    const result = await converter.handle({ identifier: id, representation, preferences });
+    expect(result).toEqual({
+      binary: false,
+      data: expect.any(Readable),
+      metadata: expect.any(RepresentationMetadata),
+    });
+    expect(result.metadata.contentType).toEqual(INTERNAL_QUADS);
+    await arrayifyStream(result.data);
+
+    expect(result.metadata.quads(null, PREFERRED_PREFIX_TERM, null)).toBeRdfIsomorphic([
+      quad(namedNode('http://xmlns.com/foaf/0.1/'), PREFERRED_PREFIX_TERM, literal('foaf'), SOLID_META.terms.ResponseMetadata),
+    ]);
+  });
+
   it('converts JSON-LD to quads.', async(): Promise<void> => {
     const metadata = new RepresentationMetadata('application/ld+json');
     const representation = new BasicRepresentation(