From d1478927bf86f3797b8bc5a44ebbff88a403d4e5 Mon Sep 17 00:00:00 2001
From: edeustace <ed.eustace@gmail.com>
Date: Sun, 21 Jun 2015 23:16:07 +0100
Subject: [PATCH 1/2] add callsFake

---
 lib/sinon/behavior.js | 12 ++++++++++--
 test/stub-test.js     | 14 +++++++++++++-
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/lib/sinon/behavior.js b/lib/sinon/behavior.js
index 0f6e3864c..4fce7b3fb 100644
--- a/lib/sinon/behavior.js
+++ b/lib/sinon/behavior.js
@@ -137,7 +137,12 @@
             },
 
             invoke: function invoke(context, args) {
-                callCallback(this, args);
+
+                if (this.callFakeFn) {
+                    this.callFakeFn.apply(null, args);
+                } else {
+                    callCallback(this, args);
+                }
 
                 if (this.exception) {
                     throw this.exception;
@@ -170,7 +175,10 @@
                 throw new Error("Defining a stub by invoking \"stub.onCall(...).withArgs(...)\" is not supported. " +
                                 "Use \"stub.withArgs(...).onCall(...)\" to define sequential behavior for calls with certain arguments.");
             },
-
+            callsFake: function callsFake(fn) {
+                this.callFakeFn = fn;
+                return this;
+            },
             callsArg: function callsArg(pos) {
                 if (typeof pos != "number") {
                     throw new TypeError("argument index is not number");
diff --git a/test/stub-test.js b/test/stub-test.js
index debffa97c..e3e7d8605 100644
--- a/test/stub-test.js
+++ b/test/stub-test.js
@@ -215,7 +215,19 @@
                 }
             }
         },
-
+        ".callsFake" : {
+
+          setUp: function () {
+              this.stub = sinon.stub.create();
+          },
+
+          "calls fake function" : function () {
+              var callback = sinon.stub.create();
+              this.stub.callsFake(callback);
+              this.stub(1, 2, callback);
+              assert(callback.called);
+          }
+        },
         ".callsArg": {
             setUp: function () {
                 this.stub = sinon.stub.create();

From 830aa74330d714397386d2f986077cb121beab58 Mon Sep 17 00:00:00 2001
From: edeustace <ed.eustace@gmail.com>
Date: Sun, 21 Jun 2015 23:21:28 +0100
Subject: [PATCH 2/2] rename callback -> fake in test

---
 test/stub-test.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/test/stub-test.js b/test/stub-test.js
index e3e7d8605..29aa7a271 100644
--- a/test/stub-test.js
+++ b/test/stub-test.js
@@ -222,10 +222,10 @@
           },
 
           "calls fake function" : function () {
-              var callback = sinon.stub.create();
-              this.stub.callsFake(callback);
-              this.stub(1, 2, callback);
-              assert(callback.called);
+              var fake = sinon.stub.create();
+              this.stub.callsFake(fake);
+              this.stub(1, 2);
+              assert(fake.calledWith(1, 2));
           }
         },
         ".callsArg": {