fix: use BlankNode according to RDF/JS spec (#346)

Co-authored-by: Tomasz Pluskiewicz <tpluscode@users.noreply.github.com>

Author: jeswr

package-lock.json

@@ -32,6 +32,7 @@
     "@babel/core": "^7.16.0",
     "@babel/preset-env": "^7.16.0",
     "@babel/register": "^7.16.0",
+    "@rdfjs/data-model": "^1",
     "arrayify-stream": "^1.0.0",
     "browserify": "^17.0.0",
     "chai": "^4.0.2",

package.json

@@ -86,7 +86,7 @@ export default class N3Parser {
       this._inversePredicate = false;
       // In N3, blank nodes are scoped to a formula
       // (using a dot as separator, as a blank node label cannot start with it)
-      this._prefixes._ = (this._graph ? `${this._graph.id.substr(2)}.` : '.');
+      this._prefixes._ = (this._graph ? `${this._graph.value}.` : '.');
       // Quantifiers are scoped to a formula
       this._quantified = Object.create(this._quantified);
     }

src/N3Parser.js

@@ -1,3 +1,4 @@
+import rdfDataModel from '@rdfjs/data-model';
 import { Parser, termFromId } from '../src/';
 import { NamedNode, BlankNode, Quad } from '../src/N3DataFactory';
 
@@ -2486,6 +2487,22 @@ describe('Parser', () => {
     });
   });
 
+  describe('A parser instance with external data factory', () => {
+    it('should parse', () => {
+      const parser = new Parser({
+        baseIRI: BASE_IRI,
+        format: 'n3',
+        factory: rdfDataModel,
+      });
+      const quads = parser.parse(`
+        @prefix : <http://example.com/> .
+        { :weather a :Raining } => { :weather a :Cloudy } .
+      `);
+
+      quads.length.should.be.gt(0);
+    });
+  });
+
   describe('IRI resolution', () => {
     describe('RFC3986 normal examples', () => {
       itShouldResolve('http://a/bb/ccc/d;p?q', 'g:h',     'g:h');