Fix similar css urls not updated (#53)

* Fix similar css urls not updates, close #48

lib/file-handlers/css.js

@@ -15,7 +15,7 @@ function loadCss (context, resource) {
 
 		return context.loadResource(cssResource).then(function handleLoadedSource (loadedResource) {
 			var relativePath = utils.getRelativePath(filename, loadedResource.getFilename());
-			text = text.replace(cssUrl, relativePath);
+			text = text.replace(new RegExp(cssUrl, 'g'), relativePath);
 			return Promise.resolve();
 		});
 	});

test/unit/file-handlers/css-test.js

@@ -112,5 +112,28 @@ describe('Css handler', function () {
 				done();
 			}).catch(done);
 		});
+
+		it('should replace all occurencies of the same sources in text with local files', function(done) {
+			sinon.stub(scraper, 'loadResource').returns(Promise.resolve(new Resource('http://example.com/img.jpg', 'local/img.jpg')));
+
+			var css = '\
+				.a {background: url("http://example.com/img.jpg")} \
+				.b {background: url("http://example.com/img.jpg")}\
+				.c {background: url("http://example.com/img.jpg")}\
+			';
+
+			var po = new Resource('http://example.com', '1.css');
+			po.setText(css);
+
+			return loadCss(scraper, po).then(function(){
+				var text = po.getText();
+				var numberOfLocalResourceMatches = text.match(/local\/img.jpg/g).length;
+
+				text.should.not.containEql('http://example.com/img.jpg');
+				text.should.containEql('local/img.jpg');
+				numberOfLocalResourceMatches.should.be.eql(3);
+				done();
+			}).catch(done);
+		});
 	});
 });