fix(withinString): allow callback to return undefined to signal no ch…

…ange - #303

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 The release notes tracked in this document are also made available on the [releases page](https://github.com/medialize/URI.js/releases)
 
+### master ###
+
+* fixing [`URI.withinString()`](http://medialize.github.io/URI.js/docs.html#static-withinString) to allow callback to return `undefined` or `string` - [Issue #303](https://github.com/medialize/URI.js/issues/303)
+
 ### 1.18.1 (May 29th 2016) ###
 
 * fixing UMD wrapper of `jquery.URI.js` - [Issue #295](https://github.com/medialize/URI.js/issues/295)

src/URI.js

@@ -968,6 +968,12 @@
 
       end = start + slice.length;
       var result = callback(slice, start, end, string);
+      if (result === undefined) {
+        _start.lastIndex = end;
+        continue;
+      }
+
+      result = String(result);
       string = string.slice(0, start) + result + string.slice(end);
       _start.lastIndex = start + result.length;
     }

test/test.js

@@ -1619,6 +1619,33 @@
 
     equal(result, expected, 'filtered in string URI identification');
   });
+  test('withinString - capture only', function() {
+    /*jshint laxbreak: true */
+    var source = 'Hello www.example.com,\n'
+      + 'http://google.com is a search engine, like http://www.bing.com\n'
+      + 'http://exämple.org/foo.html?baz=la#bumm is an IDN URL,\n'
+      + 'http://123.123.123.123/foo.html is IPv4 and http://fe80:0000:0000:0000:0204:61ff:fe9d:f156/foobar.html is IPv6.\n'
+      + 'links can also be in parens (http://example.org) or quotes »http://example.org«.';
+    var expected = [
+      'www.example.com',
+      'http://google.com',
+      'http://www.bing.com',
+      'http://exämple.org/foo.html?baz=la#bumm',
+      'http://123.123.123.123/foo.html',
+      'http://fe80:0000:0000:0000:0204:61ff:fe9d:f156/foobar.html',
+      'http://example.org',
+      'http://example.org'
+    ];
+
+    /*jshint laxbreak: false */
+    var links = [];
+    var result = URI.withinString(source, function(url) {
+      links.push(url);
+    });
+
+    deepEqual(links, expected, 'urls extracted');
+    equal(result, source, 'source not modified');
+  });
   test('noConflict', function() {
     var actual_lib = URI; // actual library; after loading, before noConflict()
     var unconflicted = URI.noConflict();