Added support for synchronous actions with transform prop but no promise

__tests__/middleware.test.js

@@ -23,7 +23,7 @@ afterEach(() => {
   store.getState.mockClear();
 });
 
-it('ignores error actions or actions without promise prop', () => {
+it('ignores error actions or actions without promise and transform props', () => {
   const action1 = { type: 'SOME_ACTION_TYPE', payload: 'some payload' };
   const action2 = {
     type: 'SOME_ACTION_TYPE',
@@ -224,3 +224,26 @@ it('supports transform prop', () => {
   expect(next.mock.calls[1][0]).toHaveProperty('type', types.SUCCESS);
   expect(next.mock.calls[1][0]).toHaveProperty('meta.useDifferentRoute', true);
 });
+
+it('handles actions with transform prop but without promise', () => {
+  const action = {
+    type: 'TAKE_ITEMS',
+    payload: ['Backpack'],
+    transform: (action, state) => (state.isSunny
+      ? { ...action, payload: action.payload.concat('Sunglasses') }
+      : action
+    ),
+  }
+
+  store.getState.mockReturnValueOnce({ isSunny: true });
+  middleware(action);
+  expect(next).toHaveBeenCalledTimes(1);
+  expect(resolve).not.toHaveBeenCalled();
+  expect(next.mock.calls[0][0]).toHaveProperty('payload.1', 'Sunglasses');
+
+  store.getState.mockReturnValueOnce({ isSunny: false });
+  middleware(action);
+  expect(next).toHaveBeenCalledTimes(2);
+  expect(resolve).not.toHaveBeenCalled();
+  expect(next.mock.calls[1][0]).not.toHaveProperty('payload.1');
+});

src/middleware.js

@@ -4,7 +4,10 @@ import createPromiseResolver from './promiseResolver';
 const HOP = Object.prototype.hasOwnProperty;
 
 const createMiddleware = (store, next, resolve) => (action) => {
-  if (!HOP.call(action, 'promise')) return next(action);
+  if (!HOP.call(action, 'promise')) {
+    if (!HOP.call(action, 'transform')) return next(action);
+    return next(action.transform(action, store.getState()));
+  }
 
   const {
     // FSA props