fix(runtime-vapor): tweak expose fallback value

Author: Doctor-wu

packages/runtime-vapor/__tests__/apiExpose.spec.ts

@@ -1,11 +1,15 @@
-import { ref } from '@vue/reactivity'
+import { ref, shallowRef } from '@vue/reactivity'
 import { createComponent } from '../src/apiCreateComponent'
 import { setRef } from '../src/dom/templateRef'
 import { makeRender } from './_utils'
+import {
+  type ComponentInternalInstance,
+  getCurrentInstance,
+} from '../src/component'
 
 const define = makeRender()
 describe('api: expose', () => {
-  test('string ref mount (component)', () => {
+  test('via setup context', () => {
     const { component: Child } = define({
       setup(_, { expose }) {
         expose({
@@ -33,4 +37,61 @@ describe('api: expose', () => {
     expect(childRef.value.bar).toBe(2)
     expect(childRef.value.baz).toBeUndefined()
   })
+
+  test('via setup context (expose empty)', () => {
+    let childInstance: ComponentInternalInstance | null = null
+    const { component: Child } = define({
+      setup(_) {
+        childInstance = getCurrentInstance()
+      },
+    })
+    const childRef = shallowRef()
+    const { render } = define({
+      render: () => {
+        const n0 = createComponent(Child)
+        setRef(n0, childRef)
+        return n0
+      },
+    })
+
+    render()
+    expect(childInstance!.exposed).toBeUndefined()
+    expect(childRef.value).toBe(childInstance!)
+  })
+
+  test('warning for ref', () => {
+    const { render } = define({
+      setup(_, { expose }) {
+        expose(ref(1))
+      },
+    })
+    render()
+    expect(
+      'expose() should be passed a plain object, received ref',
+    ).toHaveBeenWarned()
+  })
+
+  test('warning for array', () => {
+    const { render } = define({
+      setup(_, { expose }) {
+        expose(['focus'])
+      },
+    })
+    render()
+    expect(
+      'expose() should be passed a plain object, received array',
+    ).toHaveBeenWarned()
+  })
+
+  test('warning for function', () => {
+    const { render } = define({
+      setup(_, { expose }) {
+        expose(() => null)
+      },
+    })
+    render()
+    expect(
+      'expose() should be passed a plain object, received function',
+    ).toHaveBeenWarned()
+  })
 })

packages/runtime-vapor/src/dom/templateRef.ts

@@ -35,7 +35,7 @@ export function setRef(el: RefEl, ref: NodeRef, refFor = false) {
     return
   }
 
-  const refValue = isVaporComponent(el) ? el.exposed || currentInstance : el
+  const refValue = isVaporComponent(el) ? el.exposed || el : el
 
   const refs =
     currentInstance.refs === EMPTY_OBJ