test: fix script setup helpers tests

packages/runtime-core/src/apiSetupHelpers.ts

@@ -71,6 +71,10 @@ export function useContext(): SetupContext {
         `next minor release. Use \`useSlots()\` and \`useAttrs()\` instead.`
     )
   }
+  return getContext()
+}
+
+function getContext(): SetupContext {
   const i = getCurrentInstance()!
   if (__DEV__ && !i) {
     warn(`useContext() called without active instance.`)
@@ -79,9 +83,9 @@ export function useContext(): SetupContext {
 }
 
 export function useSlots(): SetupContext['slots'] {
-  return useContext().slots
+  return getContext().slots
 }
 
 export function useAttrs(): SetupContext['attrs'] {
-  return useContext().attrs
+  return getContext().attrs
 }

packages/runtime-core/src/component.ts

@@ -841,11 +841,14 @@ export function createSetupContext(
   }
 
   if (__DEV__) {
+    let attrs: Data
     // We use getters in dev in case libs like test-utils overwrite instance
     // properties (overwrites should not be done in prod)
     return Object.freeze({
       get attrs() {
-        return new Proxy(instance.attrs, attrDevProxyHandlers)
+        return (
+          attrs || (attrs = new Proxy(instance.attrs, attrDevProxyHandlers))
+        )
       },
       get slots() {
         return shallowReadonly(instance.slots)