fix(runtime-core): rework vnode hooks handling

- peroperly support directive on components (e.g. <foo v-show="x">)
- consistently invoke raw vnode hooks on component vnodes (fix #684)

packages/runtime-core/src/componentRenderUtils.ts

@@ -46,6 +46,7 @@ export function renderComponentRoot(
     props,
     slots,
     attrs,
+    vnodeHooks,
     emit
   } = instance
 
@@ -92,14 +93,23 @@ export function renderComponentRoot(
       }
     }
 
+    // inherit vnode hooks
+    if (vnodeHooks !== EMPTY_OBJ) {
+      result = cloneVNode(result, vnodeHooks)
+    }
+    // inherit directives
+    if (vnode.dirs != null) {
+      if (__DEV__ && !isElementRoot(result)) {
+        warn(
+          `Runtime directive used on component with non-element root node. ` +
+            `The directives will not function as intended.`
+        )
+      }
+      result.dirs = vnode.dirs
+    }
     // inherit transition data
     if (vnode.transition != null) {
-      if (
-        __DEV__ &&
-        !(result.shapeFlag & ShapeFlags.COMPONENT) &&
-        !(result.shapeFlag & ShapeFlags.ELEMENT) &&
-        result.type !== Comment
-      ) {
+      if (__DEV__ && !isElementRoot(result)) {
         warn(
           `Component inside <Transition> renders non-element root node ` +
             `that cannot be animated.`
@@ -115,6 +125,14 @@ export function renderComponentRoot(
   return result
 }
 
+function isElementRoot(vnode: VNode) {
+  return (
+    vnode.shapeFlag & ShapeFlags.COMPONENT ||
+    vnode.shapeFlag & ShapeFlags.ELEMENT ||
+    vnode.type === Comment // potential v-if branch switch
+  )
+}
+
 export function shouldUpdateComponent(
   prevVNode: VNode,
   nextVNode: VNode,
@@ -137,6 +155,11 @@ export function shouldUpdateComponent(
     return true
   }
 
+  // force child update on runtime directive usage on component vnode.
+  if (nextVNode.dirs != null) {
+    return true
+  }
+
   if (patchFlag > 0) {
     if (patchFlag & PatchFlags.DYNAMIC_SLOTS) {
       // slot content that references values that might have changed,
@@ -174,6 +197,7 @@ export function shouldUpdateComponent(
     }
     return hasPropsChanged(prevProps, nextProps)
   }
+
   return false
 }