fix(server-renderer): getSSRProps can get exposed property

packages/server-renderer/__tests__/ssrDirectives.spec.ts

@@ -8,7 +8,10 @@ import {
   vModelRadio,
   vModelCheckbox,
   vModelDynamic,
-  resolveDirective
+  resolveDirective,
+  mergeProps,
+  ref,
+  unref
 } from 'vue'
 import { ssrGetDirectiveProps, ssrRenderAttrs } from '../src'
 
@@ -518,4 +521,44 @@ describe('ssr: directives', () => {
       )
     ).toBe(`<div id="foo-arg-true"></div>`)
   })
+
+  // #7499
+  test('custom directive w/ getSSRProps (expose)', async () => {
+    let exposeVars: null | string | undefined = null
+    const useTestDirective = () => ({
+      vTest: {
+        getSSRProps({ instance }: any) {
+          if (instance) {
+            exposeVars = instance.x
+          }
+          return { id: exposeVars }
+        }
+      }
+    })
+    const { vTest } = useTestDirective()
+
+    const renderString = await renderToString(
+      createApp({
+        setup(props, { expose }) {
+          const x = ref('foo')
+          expose({ x })
+          const __returned__ = { useTestDirective, vTest, ref, x }
+          Object.defineProperty(__returned__, '__isScriptSetup', {
+            enumerable: false,
+            value: true
+          })
+          return __returned__
+        },
+        ssrRender(_ctx, _push, _parent, _attrs) {
+          _push(
+            `<div${ssrRenderAttrs(
+              mergeProps(_attrs!, ssrGetDirectiveProps(_ctx, unref(vTest)))
+            )}></div>`
+          )
+        }
+      })
+    )
+    expect(renderString).toBe(`<div id="foo"></div>`)
+    expect(exposeVars).toBe('foo')
+  })
 })

packages/server-renderer/src/render.ts

@@ -28,7 +28,7 @@ import {
 import { ssrRenderAttrs } from './helpers/ssrRenderAttrs'
 import { ssrCompile } from './helpers/ssrCompile'
 import { ssrRenderTeleport } from './helpers/ssrRenderTeleport'
-
+import { getExposeProxy } from '../../runtime-core/src/component'
 const {
   createComponentInstance,
   setCurrentRenderingInstance,
@@ -183,7 +183,7 @@ function renderComponentSubTree(
       const prev = setCurrentRenderingInstance(instance)
       try {
         ssrRender(
-          instance.proxy,
+          getExposeProxy(instance) || instance.proxy,
           push,
           instance,
           attrs,