处理TypeError-Converting-circular-structure-to-JSON

产生此错误的原因是因为对象中有对自身的循环引用

// Demo: Circular reference const o = {}; o.o = o;// Note: cache should not be re-used by repeated calls to JSON.stringify. let cache = []; function stringifyCircularHandler(key, value) {    if (typeof value === 'object' && value !== null) {        if (cache.indexOf(value) !== -1) {            // Circular reference found, discard key            return;        }        // Store value in our collection        cache.push(value);    }    return value;};JSON.stringify(req, stringifyCircularHandler);

reference:
https://www.cnblogs.com/rubyl...