From 56ca44f27e63e5fdc326b43550e479e4329fbaef Mon Sep 17 00:00:00 2001
From: George Schneeloch <gschneel@mit.edu>
Date: Thu, 3 Aug 2017 11:27:57 -0400
Subject: [PATCH] Add support for passing a function to stub.throws(...).

---
 docs/release-source/release/stubs.md |  5 +++++
 lib/sinon/behavior.js                |  4 ++++
 lib/sinon/default-behaviors.js       | 18 ++++++++++++++----
 test/stub-test.js                    | 27 +++++++++++++++++++++++++++
 4 files changed, 50 insertions(+), 4 deletions(-)

diff --git a/docs/release-source/release/stubs.md b/docs/release-source/release/stubs.md
index c1c5bd47f..2197723ea 100644
--- a/docs/release-source/release/stubs.md
+++ b/docs/release-source/release/stubs.md
@@ -271,6 +271,11 @@ Causes the stub to throw an exception of the provided type.
 Causes the stub to throw the provided exception object.
 
 
+#### `stub.throws(function() { return new Error(); });`
+
+Causes the stub to throw the function returned by the function.
+
+
 #### `stub.rejects();`
 
 Causes the stub to return a Promise which rejects with an exception (`Error`).
diff --git a/lib/sinon/behavior.js b/lib/sinon/behavior.js
index 489da3b36..640261fe8 100644
--- a/lib/sinon/behavior.js
+++ b/lib/sinon/behavior.js
@@ -127,6 +127,10 @@ var proto = {
 
         if (this.exception) {
             throw this.exception;
+        } else if (this.exceptionCreator) {
+            this.exception = this.exceptionCreator();
+            this.exceptionCreator = undefined;
+            throw this.exception;
         } else if (typeof this.returnArgAt === "number") {
             return args[this.returnArgAt];
         } else if (this.returnThis) {
diff --git a/lib/sinon/default-behaviors.js b/lib/sinon/default-behaviors.js
index 13a8ce7b7..46e4f160e 100644
--- a/lib/sinon/default-behaviors.js
+++ b/lib/sinon/default-behaviors.js
@@ -7,11 +7,18 @@ var useLeftMostCallback = -1;
 var useRightMostCallback = -2;
 
 function throwsException(fake, error, message) {
-    if (typeof error === "string") {
-        fake.exception = new Error(message || "");
-        fake.exception.name = error;
+    if (typeof error === "function") {
+        fake.exceptionCreator = error;
+    } else if (typeof error === "string") {
+        fake.exceptionCreator = function () {
+            var newException = new Error(message || "");
+            newException.name = error;
+            return newException;
+        };
     } else if (!error) {
-        fake.exception = new Error("Error");
+        fake.exceptionCreator = function () {
+            return new Error("Error");
+        };
     } else {
         fake.exception = error;
     }
@@ -129,6 +136,7 @@ module.exports = {
         fake.reject = false;
         fake.returnValueDefined = true;
         fake.exception = undefined;
+        fake.exceptionCreator = undefined;
         fake.fakeFn = undefined;
     },
 
@@ -158,6 +166,7 @@ module.exports = {
         fake.reject = false;
         fake.returnValueDefined = true;
         fake.exception = undefined;
+        fake.exceptionCreator = undefined;
         fake.fakeFn = undefined;
     },
 
@@ -176,6 +185,7 @@ module.exports = {
         fake.reject = true;
         fake.returnValueDefined = true;
         fake.exception = undefined;
+        fake.exceptionCreator = undefined;
         fake.fakeFn = undefined;
 
         return fake;
diff --git a/test/stub-test.js b/test/stub-test.js
index 19579aebc..fd236ea88 100644
--- a/test/stub-test.js
+++ b/test/stub-test.js
@@ -521,6 +521,22 @@ describe("stub", function () {
 
             refute.defined(stub.invoking);
         });
+
+        it("throws an exception created using a function", function () {
+            var stub = createStub.create();
+
+            function namedFunc() {
+                return new Error("not implemented");
+            }
+
+            stub.throws(namedFunc);
+
+            assert.exception(stub, {
+                message: "not implemented"
+            });
+            assert.same(stub.firstCall.exception.message, "not implemented");
+            assert.contains(stub.firstCall.toString(), "not implemented");
+        });
     });
 
     describe(".callsArg", function () {
@@ -872,6 +888,17 @@ describe("stub", function () {
             assert(stub.threw("TypeError"));
         });
 
+        it("handles threw properly for lazily instantiated Errors", function () {
+            var stub = createStub(this.object, "method");
+            stub.throws(function () {
+                return new TypeError();
+            });
+
+            assert.exception(this.object.method);
+
+            assert(stub.threw("TypeError"));
+        });
+
         it("returns standalone stub without arguments", function () {
             var stub = createStub();