Where exactly did circular reference start when JSON.stringify throws the error?

Question

Passing an object to JSON.stringify throws the error "Converting circular structure to JSON" but I'm not exactly sure why.

I'm passing the object via server-side node.js

app.get('/', function(req,res){
    res.render('index.jade', {object: object});
});

to Jade

script var table = !{JSON.stringify(object)};

And it's throwing the error when Jade tries to parse the object.

But I have no reason to believe object have circular references. Infact I do a

console.info(JSON.stringify(req.user.table.export))

right before res.render and it works fine!

Is there a way to know precisely where did the circular reference come into being?

edit found something, but unfortunately can't use it in Jade.

edit2 actually can

Answer 1

In Jade

- var cache = [];
script var table = !{JSON.stringify(table,function(key, value) {if (typeof value === 'object' && value !== null) {if (cache.indexOf(value) !== -1) {console.log('Found Circular reference: '+key);return;}cache.push(value);}return value;})};
- cache = null;

output

{"players":[{"id":"53179fd401d540b8c5000001","username":...
Found Circular reference: table
connections property is deprecated. Use getConnections() m
Found Circular reference: owner
Found Circular reference:
Found Circular reference: sockets
Found Circular reference: store
Found Circular reference: manager
Found Circular reference: manager
Found Circular reference: mime
Found Circular reference: mime
Found Circular reference: mime
Found Circular reference: mime
Found Circular reference: user
Found Circular reference: user
Found Circular reference: _idleNext
Found Circular reference: _idlePrev
Found Circular reference: _idleNext
Found Circular reference: j1sYyxSoI8LEw5DNYGUa
Found Circular reference: manager
Found Circular reference: store
Found Circular reference: table

source

no idea why it's happening though... (link to issue on /Jade github)