allow request.defaults to override the main request method

main.js

@@ -802,16 +802,23 @@ module.exports = request
 
 request.initParams = initParams;
 
-request.defaults = function (options) {
+request.defaults = function (options, requester) {
   var def = function (method) {
     var d = function (uri, opts, callback) {
       var params = initParams(uri, opts, callback);
       for (var i in options) {
         if (params.options[i] === undefined) params.options[i] = options[i]
       }
-      return method(params.options, params.callback)
+      if(typeof requester === 'function') {
+        if(method === request) {
+          method = requester;
+        } else {
+          params.options._requester = requester;
+        }
+      }
+      return method(params.options, params.callback);
     }
-    return d
+    return d;
   }
   var de = def(request)
   de.get = def(request.get)
@@ -861,6 +868,9 @@ request.head = function (uri, options, callback) {
 request.del = function (uri, options, callback) {
   var params = initParams(uri, options, callback);
   params.options.method = 'DELETE'
+  if(typeof params.options._requester === 'function') {
+    request = params.options._requester;
+  }
   return request(params.uri || null, params.options, params.callback)
 }
 request.jar = function () {

tests/test-defaults.js

@@ -61,8 +61,39 @@ s.listen(s.port, function () {
   request.defaults({headers:{foo:"bar"}}).head({uri: s.url + '/head'}, function (e, r, b){
     if (e) throw e;
     counter += 1;
-    console.log(counter.toString() + " tests passed.")
-    s.close()
   });
 
+  s.on('/get_custom', function(req, resp) {
+    assert.equal(req.headers.foo, 'bar');
+    assert.equal(req.headers.x, 'y');
+    resp.writeHead(200, {'Content-Type': 'text/plain'});
+    resp.end();
+  });
+
+  // test custom request handler function
+  var defaultRequest = request.defaults({
+    headers:{foo:"bar"}
+    , body: 'TESTING!'
+  }, function(uri, options, callback) {
+    var params = request.initParams(uri, options, callback);
+    options = params.options;
+    options.headers.x = 'y';
+
+    return request(params.uri, params.options, params.callback);
+  });
+
+  var msg = 'defaults test failed. head request should throw earlier';
+  assert.throws(function() {
+    defaultRequest.head(s.url + '/get_custom', function(e, r, b) {
+      throw new Error(msg);
+    });
+    counter+=1;
+  }, msg);
+
+  defaultRequest.get(s.url + '/get_custom', function(e, r, b) {
+    if(e) throw e;
+    counter += 1;
+    console.log(counter.toString() + " tests passed.");
+    s.close();
+  });
 })