Avoid stripping partial base IRIs.

Fixes CommunitySolidServer/CommunitySolidServer#1094

Author: RubenVerborgh

src/N3Writer.js

@@ -55,9 +55,13 @@ export default class N3Writer {
     if (!(/triple|quad/i).test(options.format)) {
       this._lineMode = false;
       this._graph = DEFAULTGRAPH;
-      this._baseIRI = options.baseIRI;
       this._prefixIRIs = Object.create(null);
       options.prefixes && this.addPrefixes(options.prefixes);
+      if (options.baseIRI) {
+        this._baseMatcher = new RegExp(`^${escapeRegex(options.baseIRI)
+            }${options.baseIRI.endsWith('/') ? '' : '[#?]'}`);
+        this._baseLength = options.baseIRI.length;
+      }
     }
     else {
       this._lineMode = true;
@@ -148,8 +152,8 @@ export default class N3Writer {
     }
     let iri = entity.value;
     // Use relative IRIs if requested and possible
-    if (this._baseIRI && iri.startsWith(this._baseIRI))
-      iri = iri.substr(this._baseIRI.length);
+    if (this._baseMatcher && this._baseMatcher.test(iri))
+      iri = iri.substr(this._baseLength);
     // Escape special characters
     if (escape.test(iri))
       iri = iri.replace(escapeAll, characterReplacer);
@@ -290,7 +294,7 @@ export default class N3Writer {
         IRIlist += IRIlist ? `|${prefixIRI}` : prefixIRI;
         prefixList += (prefixList ? '|' : '') + this._prefixIRIs[prefixIRI];
       }
-      IRIlist = IRIlist.replace(/[\]\/\(\)\*\+\?\.\\\$]/g, '\\$&');
+      IRIlist = escapeRegex(IRIlist, /[\]\/\(\)\*\+\?\.\\\$]/g, '\\$&');
       this._prefixRegex = new RegExp(`^(?:${prefixList})[^\/]*$|` +
                                      `^(${IRIlist})([a-zA-Z][\\-_a-zA-Z0-9]*)$`);
     }
@@ -389,3 +393,7 @@ function characterReplacer(character) {
   }
   return result;
 }
+
+function escapeRegex(regex) {
+  return regex.replace(/[\]\/\(\)\*\+\?\.\\\$]/g, '\\$&');
+}

test/N3Writer-test.js

@@ -349,6 +349,18 @@ describe('Writer', () => {
       });
     });
 
+    it('does not use partially match base IRIs', done => {
+      const writer = new Writer({ baseIRI: 'https://pod.example/profile/card' });
+      writer.addQuad(new Quad(
+        new NamedNode('https://pod.example/profile/card#me'),
+        new NamedNode('http://www.w3.org/2002/07/owl#sameAs'),
+        new NamedNode('https://pod.example/profile/card-1234.ttl')));
+      writer.end((error, output) => {
+        output.should.equal('<#me> <http://www.w3.org/2002/07/owl#sameAs> <https://pod.example/profile/card-1234.ttl>.\n');
+        done(error);
+      });
+    });
+
     it('should accept triples with separated components', done => {
       const writer = new Writer();
       writer.addQuad(new NamedNode('a'), new NamedNode('b'), new NamedNode('c'));