Function needTransition

packages/runtime-core/src/renderer.ts:2501–2510

(
  parentSuspense: SuspenseBoundary | null,
  transition: TransitionHooks | null,
)

}

export function needTransition(
  parentSuspense: SuspenseBoundary | null,
  transition: TransitionHooks | null,
): boolean | null {
  return (
    (!parentSuspense || (parentSuspense && !parentSuspense.pendingBranch)) &&
    transition &&
    !transition.persisted
  )
}

/**
 * #1156