message: fix(router-view): return one node when possible
  Fix
diff: @@ -12,6 +12,7 @@ import {
  AllowedComponentProps,
  ComponentCustomProps,
  watch,
  + Slot,
  } from 'vue'
  import {
  RouteLocationNormalized,
  @@ -100,9 +101,7 @@ export const RouterViewImpl = /*#__PURE__*/ defineComponent({
  const currentName = props.name
  if (!ViewComponent) {
  - return slots.default
  - ? slots.default({ Component: ViewComponent, route })
  - : null
  + return normalizeSlot(slots.default, { Component: ViewComponent, route })
  }
  // props from route configuration
  @@ -133,14 +132,19 @@ export const RouterViewImpl = /*#__PURE__*/ defineComponent({
  return (
  // pass the vnode to the slot as a prop.
  // h and <component :is="..."> both accept vnodes
  - slots.default
  - ? slots.default({ Component: component, route })
  - : component
  + normalizeSlot(slots.default, { Component: component, route }) ||
  + component
  )
  }
  },
  })
  +function normalizeSlot(slot: Slot | undefined, data: any) {
  + if (!slot) return null
  + const slotContent = slot(data)
  + return slotContent.length === 1 ? slotContent[0] : slotContent
  +}
  +
  // export the public type for h/tsx inference
  // also to avoid inline import() in generated d.ts files
  /**
  