From d575747aa5984f593f26b209b0dc665bcb804932 Mon Sep 17 00:00:00 2001
From: Jamie Dixon <jamie@jamie-dixon.co.uk>
Date: Sat, 30 Jan 2016 09:59:27 +0000
Subject: [PATCH 1/5] Added check to createStore.subscribe to ensure listener
 is a function

---
 src/createStore.js       | 4 ++++
 test/createStore.spec.js | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/src/createStore.js b/src/createStore.js
index a1fec48ca6..66f9ee1bf2 100644
--- a/src/createStore.js
+++ b/src/createStore.js
@@ -79,6 +79,10 @@ export default function createStore(reducer, initialState, enhancer) {
    * @returns {Function} A function to remove this change listener.
    */
   function subscribe(listener) {
+    if (typeof listener !== 'function') {
+      throw new Error('Expected the nextReducer to be a function.')
+    }
+
     listeners.push(listener)
     var isSubscribed = true
 
diff --git a/test/createStore.spec.js b/test/createStore.spec.js
index 1143ce5f94..e98473f8ac 100644
--- a/test/createStore.spec.js
+++ b/test/createStore.spec.js
@@ -548,4 +548,12 @@ describe('createStore', () => {
       store.replaceReducer(() => {})
     ).toNotThrow()
   })
+
+  it('throws if listener is not a function', () => {
+    const store = createStore(reducers.todos)
+
+    expect(() =>
+      store.subscribe()
+    ).toThrow();
+  })
 })

From 40fd771ae035dacb9c67c39e8a4faaa4b8560d21 Mon Sep 17 00:00:00 2001
From: Jamie Dixon <jamie@jamie-dixon.co.uk>
Date: Sat, 30 Jan 2016 10:02:37 +0000
Subject: [PATCH 2/5] Replaced error message with correct arg name

---
 src/createStore.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/createStore.js b/src/createStore.js
index 66f9ee1bf2..9e253729f9 100644
--- a/src/createStore.js
+++ b/src/createStore.js
@@ -80,7 +80,7 @@ export default function createStore(reducer, initialState, enhancer) {
    */
   function subscribe(listener) {
     if (typeof listener !== 'function') {
-      throw new Error('Expected the nextReducer to be a function.')
+      throw new Error('Expected listener to be a function.')
     }
 
     listeners.push(listener)

From 0c5181977c79424d730e8077fec67b40c2297a9f Mon Sep 17 00:00:00 2001
From: Jamie Dixon <jamie@jamie-dixon.co.uk>
Date: Sat, 30 Jan 2016 10:11:40 +0000
Subject: [PATCH 3/5] Removed semi-colon from end of toThrow()

---
 test/createStore.spec.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/createStore.spec.js b/test/createStore.spec.js
index e98473f8ac..7a5f7d8b22 100644
--- a/test/createStore.spec.js
+++ b/test/createStore.spec.js
@@ -554,6 +554,6 @@ describe('createStore', () => {
 
     expect(() =>
       store.subscribe()
-    ).toThrow();
+    ).toThrow()
   })
 })

From 5279a93f4cf83229f7febd1bacc045c36c26f76d Mon Sep 17 00:00:00 2001
From: Jamie Dixon <jamie@jamie-dixon.co.uk>
Date: Sat, 30 Jan 2016 10:21:35 +0000
Subject: [PATCH 4/5] Added tests for more deta types passed to
 createStore.subscribe

---
 test/createStore.spec.js | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/test/createStore.spec.js b/test/createStore.spec.js
index 7a5f7d8b22..fff419aa43 100644
--- a/test/createStore.spec.js
+++ b/test/createStore.spec.js
@@ -555,5 +555,18 @@ describe('createStore', () => {
     expect(() =>
       store.subscribe()
     ).toThrow()
+
+    expect(() =>
+      store.subscribe('')
+    ).toThrow()
+
+    expect(() =>
+      store.subscribe(null)
+    ).toThrow()
+
+    expect(() =>
+      store.subscribe(undefined)
+    ).toThrow()
+
   })
 })

From 69f8d977625b35d22d72ec6df54c3aab7f59a62a Mon Sep 17 00:00:00 2001
From: Jamie Dixon <jamie@jamie-dixon.co.uk>
Date: Sat, 30 Jan 2016 10:40:04 +0000
Subject: [PATCH 5/5] Removed extra new line after last assertion

---
 test/createStore.spec.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/test/createStore.spec.js b/test/createStore.spec.js
index fff419aa43..d4c4b1af37 100644
--- a/test/createStore.spec.js
+++ b/test/createStore.spec.js
@@ -567,6 +567,5 @@ describe('createStore', () => {
     expect(() =>
       store.subscribe(undefined)
     ).toThrow()
-
   })
 })