fix(core): should preserve reactivity-ness of injected objects

fix #5913

src/core/instance/inject.js

@@ -3,7 +3,7 @@
 import { warn } from '../util/index'
 import { hasOwn } from 'shared/util'
 import { hasSymbol } from 'core/util/env'
-import { defineReactive } from '../observer/index'
+import { defineReactive, observerState } from '../observer/index'
 
 export function initProvide (vm: Component) {
   const provide = vm.$options.provide
@@ -17,6 +17,7 @@ export function initProvide (vm: Component) {
 export function initInjections (vm: Component) {
   const result = resolveInject(vm.$options.inject, vm)
   if (result) {
+    observerState.shouldConvert = false
     Object.keys(result).forEach(key => {
       /* istanbul ignore else */
       if (process.env.NODE_ENV !== 'production') {
@@ -32,6 +33,7 @@ export function initInjections (vm: Component) {
         defineReactive(vm, key, result[key])
       }
     })
+    observerState.shouldConvert = true
   }
 }
 

test/unit/features/options/inject.spec.js

@@ -1,5 +1,6 @@
 import Vue from 'vue'
-import { isNative } from 'core/util/env'
+import { Observer } from 'core/observer/index'
+import { isNative, isObject, hasOwn } from 'core/util/index'
 
 describe('Options provide/inject', () => {
   let injected
@@ -399,4 +400,46 @@ describe('Options provide/inject', () => {
 
     expect(injected).toEqual(['foo', 'bar'])
   })
+
+  // #5913
+  it('should keep the reactive with provide', () => {
+    function isObserver (obj) {
+      if (isObject(obj)) {
+        return hasOwn(obj, '__ob__') && obj.__ob__ instanceof Observer
+      }
+      return false
+    }
+
+    const vm = new Vue({
+      template: `<div><child ref='child'></child></div>`,
+      data () {
+        return {
+          foo: {},
+          $foo: {},
+          foo1: []
+        }
+      },
+      provide () {
+        return {
+          foo: this.foo,
+          $foo: this.$foo,
+          foo1: this.foo1,
+          bar: {},
+          baz: []
+        }
+      },
+      components: {
+        child: {
+          inject: ['foo', '$foo', 'foo1', 'bar', 'baz'],
+          template: `<span/>`
+        }
+      }
+    }).$mount()
+    const child = vm.$refs.child
+    expect(isObserver(child.foo)).toBe(true)
+    expect(isObserver(child.$foo)).toBe(false)
+    expect(isObserver(child.foo1)).toBe(true)
+    expect(isObserver(child.bar)).toBe(false)
+    expect(isObserver(child.baz)).toBe(false)
+  })
 })