Transaction behaviour of dispatch()

src/createStore.js

@@ -39,6 +39,7 @@ export default function createStore(reducer, initialState) {
   var currentState = initialState;
   var listeners = [];
   var isDispatching = false;
+  var inTransaction = false;
 
   /**
    * Reads the state tree managed by the store.
@@ -117,10 +118,42 @@ export default function createStore(reducer, initialState) {
       isDispatching = false;
     }
 
-    listeners.slice().forEach(listener => listener());
+    if (!inTransaction) {
+      listeners.slice().forEach(listener => listener());
+    }
     return action;
   }
 
+  /**
+   * Start transaction
+   *
+   * No one listeners will be called until commit() transaction.
+   *
+   * @return {void}
+   */
+  function begin() {
+    if (inTransaction) {
+      throw new Error(
+        'Only one transaction may be started with begin() call.'
+      );
+    }
+    inTransaction = true;
+  }
+
+  /**
+   * Commit
+   * @return {void}
+   */
+  function commit() {
+    if (!inTransaction) {
+      throw new Error(
+        'You must call begin() before commit().'
+      );
+    }
+    inTransaction = false;
+    listeners.slice().forEach(listener => listener());
+  }
+
   /**
    * Replaces the reducer currently used by the store to calculate the state.
    *
@@ -142,6 +175,8 @@ export default function createStore(reducer, initialState) {
   dispatch({ type: ActionTypes.INIT });
 
   return {
+    begin,
+    commit,
     dispatch,
     subscribe,
     getState,

test/createStore.spec.js

@@ -8,11 +8,13 @@ describe('createStore', () => {
     const store = createStore(combineReducers(reducers));
     const methods = Object.keys(store);
 
-    expect(methods.length).toBe(4);
+    expect(methods.length).toBe(6);
     expect(methods).toContain('subscribe');
     expect(methods).toContain('dispatch');
     expect(methods).toContain('getState');
     expect(methods).toContain('replaceReducer');
+    expect(methods).toContain('begin');
+    expect(methods).toContain('commit');
   });
 
   it('should require a reducer function', () => {
@@ -321,4 +323,23 @@ describe('createStore', () => {
       store.dispatch({ type: '' })
     ).toNotThrow();
   });
+
+  it('should not call listeners if begin() called', () => {
+    const store = createStore(reducers.todos);
+    let called = false;
+    store.subscribe(() => {
+      called = true;
+    });
+
+    store.dispatch({type: 'test'});
+    expect(called).toBe(true);
+    called = false;
+
+    store.begin();
+    store.dispatch({type: 'test'});
+    expect(called).toBe(false);
+
+    store.commit();
+    expect(called).toBe(true);
+  });
 });