JAVASCRIPT

UnhandledPromiseRejectionWarning: TypeError: Converting circular structure to JSON

I also ran into this issue. It was because I forgot to await for a promise.

converting circular structure to json

check if you have not added async and await

full problem can be like this:
Converting circular structure to JSON
    --> starting at object with constructor 'MongoClient'
    |     property 's' -> object with constructor 'Object'
    |     property 'sessionPool' -> object with constructor 'ServerSessionPool'
    --- property 'client' closes the circle

Converting circular structure to JSON

//The error means that the object you pass in the request has a circular reference, something like:

var a = {};
a.b = a;

converting circular structure to json

var win = window.open('http://www.google.com', 'google','width=800,height=600,status=0,toolbar=0'); 
var timer = setInterval(function() { 
    if(win.closed) {
        clearInterval(timer);
        alert('closed');
    }
}, 1000);

TypeError: Converting circular structure to JSON

I run into this issue, because i was sending as response the full response of another api call instead of just the data i needed.

ERROR TypeError: Converting circular structure to JSON - Solution

ficheiro.html
<form novalidate #formulario="ngForm">

<pre>{{ formulario.form | json }}</pre>

</form>

Result : ficheiro.html

{
  "_hasOwnPendingAsyncValidator": false,
  "_parent": null,
  "pristine": true,
  "touched": false,
  "_onDisabledChange": [],
  "_rawValidators": null,
  "_rawAsyncValidators": null,
  "_composedValidatorFn": null,
  "_composedAsyncValidatorFn": null,
  "controls": {},
  "valueChanges": {
    "_isScalar": false,
    "observers": [],
    "closed": false,
    "isStopped": false,
    "hasError": false,
    "thrownError": null,
    "__isAsync": false
  },
  "statusChanges": {
    "_isScalar": false,
    "observers": [],
    "closed": false,
    "isStopped": false,
    "hasError": false,
    "thrownError": null,
    "__isAsync": false
  },
  "status": "VALID",
  "value": {},
  "errors": null
}