feat(createElement): allow createElement to bind vm (#920)

Author: MinatoHikari

src/apis/createElement.ts

@@ -1,12 +1,40 @@
 import type { CreateElement } from 'vue'
-import { getVueConstructor, getCurrentInstance } from '../runtimeContext'
+import {
+  getVueConstructor,
+  getCurrentInstance,
+  ComponentInternalInstance,
+} from '../runtimeContext'
 import { defineComponentInstance } from '../utils/helper'
 import { warn } from '../utils'
+import { AsyncComponent, Component } from 'vue/types/options'
+import { VNode, VNodeChildren, VNodeData } from 'vue/types/vnode'
+
+export interface H extends CreateElement {
+  (
+    this: ComponentInternalInstance | null,
+    tag?:
+      | string
+      | Component<any, any, any, any>
+      | AsyncComponent<any, any, any, any>
+      | (() => Component),
+    children?: VNodeChildren
+  ): VNode
+  (
+    this: ComponentInternalInstance | null,
+    tag?:
+      | string
+      | Component<any, any, any, any>
+      | AsyncComponent<any, any, any, any>
+      | (() => Component),
+    data?: VNodeData,
+    children?: VNodeChildren
+  ): VNode
+}
 
 let fallbackCreateElement: CreateElement
 
-export const createElement = function createElement(...args: any) {
-  const instance = getCurrentInstance()?.proxy
+export const createElement = function createElement(this, ...args: any) {
+  const instance = this ? this.proxy : getCurrentInstance()?.proxy
   if (!instance) {
     __DEV__ &&
       warn('`createElement()` has been called outside of render function.')
@@ -20,4 +48,4 @@ export const createElement = function createElement(...args: any) {
   }
 
   return instance.$createElement.apply(instance, args)
-} as CreateElement
+} as H