support watch option alternative syntax

src/instance/events.js

@@ -42,18 +42,19 @@ function registerCallbacks (vm, action, hash) {
  * @param {Vue} vm
  * @param {String} action
  * @param {String} key
- * @param {*} handler
+ * @param {Function|String|Object} handler
+ * @param {Object} [options]
  */
 
-function register (vm, action, key, handler) {
+function register (vm, action, key, handler, options) {
   var type = typeof handler
   if (type === 'function') {
-    vm[action](key, handler)
+    vm[action](key, handler, options)
   } else if (type === 'string') {
     var methods = vm.$options.methods
     var method = methods && methods[handler]
     if (method) {
-      vm[action](key, method)
+      vm[action](key, method, options)
     } else {
       _.warn(
         'Unknown method: "' + handler + '" when ' +
@@ -61,6 +62,8 @@ function register (vm, action, key, handler) {
         ': "' + key + '".'
       )
     }
+  } else if (handler && type === 'object') {
+    register(vm, action, key, handler.handler, handler)
   }
 }
 

test/unit/specs/instance/events_spec.js

@@ -57,25 +57,40 @@ describe('Instance Events', function () {
     it('normal', function (done) {
       var spyA = jasmine.createSpy()
       var spyB = jasmine.createSpy()
+      var count = 0
+      var a = {
+        b: { c: 1 }
+      }
       var vm = new Vue({
         watch: {
           'a.b.c': spyA,
-          'b + c': spyB
+          'b + c': spyB,
+          a: {
+            deep: true,
+            immediate: true,
+            handler: 'test'
+          }
         },
         data: {
-          a: {
-            b: { c: 1 }
-          },
+          a: a,
           b: 1,
           c: 2
+        },
+        methods: {
+          test: function (val) {
+            count++
+            expect(val).toBe(a)
+          }
         }
       })
       vm.a.b.c = 2
       vm.b = 3
       vm.c = 4
+      expect(count).toBe(1)
       _.nextTick(function () {
         expect(spyA).toHaveBeenCalledWith(2, 1)
         expect(spyB).toHaveBeenCalledWith(7, 3)
+        expect(count).toBe(2)
         done()
       })
     })
@@ -273,4 +288,4 @@ describe('Instance Events', function () {
 
   })
 
-})
+})