Merge pull request #939 from jzlxiaohei/master

fixed unsubscribe bug for issue #938

Author: gaearon

src/createStore.js

@@ -62,7 +62,9 @@ export default function createStore(reducer, initialState) {
 
     return function unsubscribe() {
       var index = listeners.indexOf(listener);
-      listeners.splice(index, 1);
+      if (index !== -1) {
+        listeners.splice(index, 1);
+      }
     };
   }
 

test/createStore.spec.js

@@ -201,6 +201,23 @@ describe('createStore', () => {
     expect(listenerB.calls.length).toBe(2);
   });
 
+  it('should only remove relevant listener no matter how many times unsubscribe called', () => {
+    const store = createStore(reducers.todos);
+    const listenerA = expect.createSpy(() => {});
+    const listenerB = expect.createSpy(() => {});
+
+    const unsubscribeA = store.subscribe(listenerA);
+    store.subscribe(listenerB);
+
+    unsubscribeA();
+    unsubscribeA();
+
+    store.dispatch(unknownAction());
+    expect(listenerA.calls.length).toBe(0);
+    expect(listenerB.calls.length).toBe(1);
+  });
+
+
   it('should support removing a subscription within a subscription', () => {
     const store = createStore(reducers.todos);
     const listenerA = expect.createSpy(() => {});