wip: render function compat

packages/runtime-core/src/component.ts

@@ -54,6 +54,9 @@ import { CompilerOptions } from '@vue/compiler-core'
 import { markAttrsAccessed } from './componentRenderUtils'
 import { currentRenderingInstance } from './componentRenderContext'
 import { startMeasure, endMeasure } from './profiling'
+import { isCompatEnabled } from './compat/compatConfig'
+import { DeprecationTypes, warnDeprecation } from './compat/deprecations'
+import { compatH } from './compat/renderFn'
 
 export type Data = Record<string, unknown>
 
@@ -681,6 +684,18 @@ export function finishComponentSetup(
 ) {
   const Component = instance.type as ComponentOptions
 
+  if (
+    __COMPAT__ &&
+    Component.render &&
+    isCompatEnabled(DeprecationTypes.RENDER_FUNCTION)
+  ) {
+    warnDeprecation(DeprecationTypes.RENDER_FUNCTION)
+    const originalRender = Component.render
+    Component.render = function compatRender() {
+      return originalRender.call(this, compatH)
+    }
+  }
+
   // template / render function normalization
   if (__NODE_JS__ && isSSR) {
     // 1. the render function may already exist, returned by `setup`