在尝试用jQuery构建下面的消息时，我也遇到过同样的错误。循环引用发生在reviewerName被错误地分配给msg.detail.reviewerName时。JQuery的.val()修复了这个问题，参见最后一行。

var reviewerName = $('reviewerName'); // <input type="text" id="taskName" />;
var msg = {"type":"A", "detail":{"managerReview":true} };
msg.detail.reviewerName = reviewerName; // Error
msg.detail.reviewerName = reviewerName.val(); // Fixed

根据MDN: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify#issue_with_json.stringify_when_serializing_circular_references

它是一个循环json，不能直接转换。

解决方案1:

https://www.npmjs.com/package/flatted

// ESM
import {parse, stringify, toJSON, fromJSON} from 'flatted';

// CJS
const {parse, stringify, toJSON, fromJSON} = require('flatted');

const a = [{}];
a[0].a = a;
a.push(a);

stringify(a); // [["1","0"],{"a":"0"}]

解决方案2:(同样通过MDN)

https://github.com/douglascrockford/JSON-js

Node.js v10.22.1(在我们的GitLab CI服务器上运行的版本)有一个我认为是错误的循环引用检测器。本地运行的版本(v12.8.0)足够智能，可以知道它不是真正的循环引用。

我添加这个响应是为了防止其他人有同样的问题，而他们的对象实际上不是循环引用。

这是原始的响应对象:

var res = {
    "status":"OK",
    "message":"Success",
    "errCode":":",
    "data":"",
    "appCfg":{
        "acp_age":"2yy",
        "acp_us":"yes",
        "mode":"admin",
        "version":"v1.21.07.1"
    },
    "reqID":59833,
    "email":{
        "status":"OK",
        "message":"Success"
    },
    "emailStatus":"sent"
}

它认为res.email.status和res.status是一样的。它只是一个文本元素，所以不是循环的，但是名称和值显然打乱了JSON。stringify解析器。

我删除了res.email子对象，一切正常。我试图从服务器调用期间执行的所有独特操作中收集独立状态和详细消息。我将其切换到元素res.emailStatus，该元素也包含在上面的示例中。

根据Mozilla的JSON文档，JSON。Stringify有第二个参数替换器，可以用来在解析树时过滤/忽略子项。然而，也许您可以避免循环引用。

在Node.js中我们不能。所以我们可以这样做:

function censor(censor) {
  var i = 0;
  
  return function(key, value) {
    if(i !== 0 && typeof(censor) === 'object' && typeof(value) == 'object' && censor == value) 
      return '[Circular]'; 
    
    if(i >= 29) // seems to be a harded maximum of 30 serialized objects?
      return '[Unknown]';
    
    ++i; // so we know we aren't using the original object anymore
    
    return value;  
  }
}

var b = {foo: {bar: null}};

b.foo.bar = b;

console.log("Censoring: ", b);

console.log("Result: ", JSON.stringify(b, censor(b)));

结果:

Censoring:  { foo: { bar: [Circular] } }
Result: {"foo":{"bar":"[Circular]"}}

不幸的是，在自动假设它是循环之前，它似乎最多迭代了30次。否则，这应该可以工作。我甚至在这里使用了areEquivalent, JSON。Stringify在30次迭代之后仍然抛出异常。尽管如此，如果您确实需要的话，在顶层获得对象的体面表示已经足够好了。也许有人可以改进一下?在Node.js的HTTP请求对象，我得到:

{
"limit": null,
"size": 0,
"chunks": [],
"writable": true,
"readable": false,
"_events": {
    "pipe": [null, null],
    "error": [null]
},
"before": [null],
"after": [],
"response": {
    "output": [],
    "outputEncodings": [],
    "writable": true,
    "_last": false,
    "chunkedEncoding": false,
    "shouldKeepAlive": true,
    "useChunkedEncodingByDefault": true,
    "_hasBody": true,
    "_trailer": "",
    "finished": false,
    "socket": {
        "_handle": {
            "writeQueueSize": 0,
            "socket": "[Unknown]",
            "onread": "[Unknown]"
        },
        "_pendingWriteReqs": "[Unknown]",
        "_flags": "[Unknown]",
        "_connectQueueSize": "[Unknown]",
        "destroyed": "[Unknown]",
        "bytesRead": "[Unknown]",
        "bytesWritten": "[Unknown]",
        "allowHalfOpen": "[Unknown]",
        "writable": "[Unknown]",
        "readable": "[Unknown]",
        "server": "[Unknown]",
        "ondrain": "[Unknown]",
        "_idleTimeout": "[Unknown]",
        "_idleNext": "[Unknown]",
        "_idlePrev": "[Unknown]",
        "_idleStart": "[Unknown]",
        "_events": "[Unknown]",
        "ondata": "[Unknown]",
        "onend": "[Unknown]",
        "_httpMessage": "[Unknown]"
    },
    "connection": "[Unknown]",
    "_events": "[Unknown]",
    "_headers": "[Unknown]",
    "_headerNames": "[Unknown]",
    "_pipeCount": "[Unknown]"
},
"headers": "[Unknown]",
"target": "[Unknown]",
"_pipeCount": "[Unknown]",
"method": "[Unknown]",
"url": "[Unknown]",
"query": "[Unknown]",
"ended": "[Unknown]"
}

我创建了一个小的Node.js模块来做这件事:https://github.com/ericmuyser/stringy欢迎改进/贡献!

我得到了同样的错误与jQuery formvaliadator，但当我删除了一个console.log内部的成功:功能，它工作。

在我的情况下，我只是忘记使用async/await的东西，而构建路由:

app.get('/products', async (req, res) => {
    const products = await Product.find();
    res.send(products );
});