Push in named regexp groups as numbers

Author: blakeembrey

index.js

@@ -4,6 +4,11 @@
 
 module.exports = pathtoRegexp;
 
+/**
+ * Match matching groups in a regular expression.
+ */
+var MATCHING_GROUP_REGEXP = /\((?!\?)/g;
+
 /**
  * Normalize the given path string,
  * returning a regular expression.
@@ -28,8 +33,19 @@ function pathtoRegexp(path, keys, options) {
   var flags = options.sensitive ? '' : 'i';
   var extraOffset = 0;
   var keysOffset = keys.length;
+  var i = 0;
+  var name = 0;
+  var m;
 
   if (path instanceof RegExp) {
+    while (m = MATCHING_GROUP_REGEXP.exec(path.source)) {
+      keys.push({
+        name: name++,
+        optional: false,
+        offset: m.index
+      });
+    }
+
     return path;
   }
 
@@ -81,13 +97,8 @@ function pathtoRegexp(path, keys, options) {
       return '(.*)';
     });
 
-  // This is a workaround for handling *all* matching group positioning.
-  var re = /\((?!\?)/g;
-  var i = 0;
-  var name = 0;
-  var m;
-
-  while (m = re.exec(path)) {
+  // This is a workaround for handling unnamed matching groups.
+  while (m = MATCHING_GROUP_REGEXP.exec(path)) {
     if (keysOffset + i === keys.length || keys[keysOffset + i].offset > m.index) {
       keys.splice(keysOffset + i, 0, {
         name: name++, // Unnamed matching groups must be consistently linear.

test.js

@@ -707,6 +707,22 @@ describe('path-to-regexp', function () {
     it('should return the regexp', function () {
       assert.deepEqual(pathToRegExp(/.*/), /.*/);
     });
+
+    it('should pull out matching groups', function () {
+      var params = [];
+      var re = pathToRegExp(/(.*)/, params);
+      var m;
+
+      assert.equal(params.length, 1);
+      assert.equal(params[0].name, 0);
+      assert.equal(params[0].optional, false);
+
+      m = re.exec('/route');
+
+      assert.equal(m.length, 2);
+      assert.equal(m[0], '/route');
+      assert.equal(m[1], '/route');
+    });
   });
 
   describe('arrays', function () {