Action before and after subscribers

src/store.js

@@ -128,19 +128,28 @@ export class Store {
       return
     }
 
-    this._actionSubscribers.forEach(sub => sub(action, this.state))
+    this._actionSubscribers
+      .filter(sub => sub.before)
+      .forEach(sub => sub.before(action, this.state))
 
-    return entry.length > 1
+    const result = entry.length > 1
       ? Promise.all(entry.map(handler => handler(payload)))
       : entry[0](payload)
+
+    result.then(() => this._actionSubscribers
+      .filter(sub => sub.after)
+      .forEach(sub => sub.after(action, this.state)))
+
+    return result
   }
 
   subscribe (fn) {
     return genericSubscribe(fn, this._subscribers)
   }
 
   subscribeAction (fn) {
-    return genericSubscribe(fn, this._actionSubscribers)
+    const subs = typeof fn === 'function' ? { before: fn } : fn
+    return genericSubscribe(subs, this._actionSubscribers)
   }
 
   watch (getter, cb, options) {

test/unit/modules.spec.js

@@ -668,6 +668,37 @@ describe('Modules', () => {
         store.state
       )
     })
+
+    it('action before/after subscribers', (done) => {
+      const beforeSpy = jasmine.createSpy()
+      const afterSpy = jasmine.createSpy()
+      const store = new Vuex.Store({
+        actions: {
+          [TEST]: () => new Promise(resolve => resolve())
+        },
+        plugins: [
+          store => {
+            store.subscribeAction({
+              before: beforeSpy,
+              after: afterSpy
+            })
+          }
+        ]
+      })
+      store.dispatch(TEST, 2)
+      expect(beforeSpy).toHaveBeenCalledWith(
+        { type: TEST, payload: 2 },
+        store.state
+      )
+      expect(afterSpy).not.toHaveBeenCalled()
+      Vue.nextTick(() => {
+        expect(afterSpy).toHaveBeenCalledWith(
+          { type: TEST, payload: 2 },
+          store.state
+        )
+        done()
+      })
+    })
   })
 
   it('asserts a mutation should be a function', () => {