From b723992f7aa4cc48b43f493352fa771f49956a58 Mon Sep 17 00:00:00 2001
From: Viktor Zozulyak <zozulyakviktor@gmail.com>
Date: Sun, 1 Jan 2017 20:10:45 +0100
Subject: [PATCH] Always chain behavior with stub

---
 lib/sinon/behavior.js | 40 ++++++++++++++++++++++++----------------
 test/stub-test.js     | 11 +++++++++++
 2 files changed, 35 insertions(+), 16 deletions(-)

diff --git a/lib/sinon/behavior.js b/lib/sinon/behavior.js
index fdba4e4b6..0bf20b1df 100644
--- a/lib/sinon/behavior.js
+++ b/lib/sinon/behavior.js
@@ -42,7 +42,7 @@ function throwsException(error, message) {
         this.exception = error;
     }
 
-    return this;
+    return this.chain();
 }
 
 function getCallback(behavior, args) {
@@ -182,7 +182,7 @@ var proto = {
 
     callsFake: function callsFake(fn) {
         this.fakeFn = fn;
-        return this;
+        return this.chain();
     },
 
     callsArg: function callsArg(pos) {
@@ -196,7 +196,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     callsArgOn: function callsArgOn(pos, context) {
@@ -210,7 +210,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     callsArgWith: function callsArgWith(pos) {
@@ -224,7 +224,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     callsArgOnWith: function callsArgWith(pos, context) {
@@ -238,7 +238,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     yields: function () {
@@ -248,7 +248,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     yieldsRight: function () {
@@ -258,7 +258,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     yieldsOn: function (context) {
@@ -268,7 +268,7 @@ var proto = {
         this.callArgProp = undefined;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     yieldsTo: function (prop) {
@@ -278,7 +278,7 @@ var proto = {
         this.callArgProp = prop;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     yieldsToOn: function (prop, context) {
@@ -288,7 +288,7 @@ var proto = {
         this.callArgProp = prop;
         this.callbackAsync = false;
 
-        return this;
+        return this.chain();
     },
 
     throws: throwsException,
@@ -302,7 +302,7 @@ var proto = {
         this.exception = undefined;
         this.fakeFn = undefined;
 
-        return this;
+        return this.chain();
     },
 
     returnsArg: function returnsArg(pos) {
@@ -312,13 +312,13 @@ var proto = {
 
         this.returnArgAt = pos;
 
-        return this;
+        return this.chain();
     },
 
     returnsThis: function returnsThis() {
         this.returnThis = true;
 
-        return this;
+        return this.chain();
     },
 
     resolves: function resolves(value) {
@@ -329,7 +329,7 @@ var proto = {
         this.exception = undefined;
         this.fakeFn = undefined;
 
-        return this;
+        return this.chain();
     },
 
     rejects: function rejects(error, message) {
@@ -349,7 +349,15 @@ var proto = {
         this.exception = undefined;
         this.fakeFn = undefined;
 
-        return this;
+        return this.chain();
+    },
+
+    chain: function chain() {
+        /**
+         * "this" is stub when method is called directly on stub, e.g. stub.returns(123);
+         * "this.stub" exists when method is called from onCall chaining, e.g. stub.onCall(0).returns(123)
+         */
+        return this.stub || this;
     }
 };
 
diff --git a/test/stub-test.js b/test/stub-test.js
index 6fb09d69f..c3efaffc8 100644
--- a/test/stub-test.js
+++ b/test/stub-test.js
@@ -1719,6 +1719,17 @@ describe("stub", function () {
             }
         });
 
+        it("supports chained declaration of behavior", function () {
+            var stub = createStub()
+                    .onCall(0).returns(1)
+                    .onCall(1).returns(2)
+                    .onCall(2).returns(3);
+
+            assert.same(stub(), 1);
+            assert.same(stub(), 2);
+            assert.same(stub(), 3);
+        });
+
         describe("in combination with withArgs", function () {
             it("can produce a sequence for a fake", function () {
                 var stub = createStub().returns(0);