structuredClone preserves Error cause references and drops falsy causes

Description

The React Native structuredClone polyfill passes Error.cause through by reference instead of cloning it, and only copies the property when its value is truthy. Object causes therefore remain shared with the input; a circular cause points back to the original Error; and valid falsy causes such as false disappear.

Expected behavior

An own cause property should be cloned recursively, retain its non-enumerable Error property descriptor, preserve circular/shared identity within the clone, and keep falsy values. Node's native structuredClone follows this behavior.

React Native Version

0.87.1 and current main

Affected Platforms

JavaScript runtime - All

首先定位 React Native 的 structuredClone polyfill，并检查它如何处理 Error.cause。将其行为与 Node 的原生 structuredClone 进行比较，然后添加覆盖测试，展示递归克隆、保留循环/共享 identity、不可枚举 descriptor 以及 falsy causes。