React Native JSON.stringify cannot serialize cyclical structures

Question

We're building a RN app (RN0.37), and we're running into an issue where when the app is run, we get a "TypeError: JSON.stringify cannot serialize cyclic structures".

Nothing of relevance has changed on the API responses, and the issues went away recently, but reappeared upon a wipe/rebuild (triggered by unrelated issues).

My suspicions are around a couple of packages being used: “react-native-router-flux” and "react-native-permissions”, but I haven't been able to find anything of relevance in the app.

Currently my suspicions around "react-native-router-flux" are mainly based around this article: https://github.com/aksonov/react-native-router-flux/issues/363

And my suspicions around "react-native-permissions" is mostly founded on the fact that the timing of the inclusion of this package on this project is suspicious, and seems to coincide with the surfacing of this error - although I can't prove that with absolute certainty.

The only additional clue I have, is that the JSON.stringify error always seems to be preceded by a list of warnings. They all read "This synthetic event is reused for performance reasons. If you're seeing this, you're accessing the property on a released/nullified synthetic event. This is set to null. If you must keep the original synthetic event around, use event.persist(). See https://facebook.github.io/react/docs/events.html#event-pooling for more information." The list of goes as follows (always in the same order): nativeEvent, type, target, currentTarget, eventPhase, bubbles, cancelable, timeStamp, defaultPrevented, isTrusted and touchHistory.

The following is my package.json:

"dependencies": {
  "blueimp-md5": "2.5.0",
  "moment": "2.16.0",
  "phone-formatter": "0.0.2",
  "react": "15.3.2",
  "react-native": "0.37.0",
  "react-native-asset-library-to-base64": "1.0.1",
  "react-native-aws3": "0.0.3",
  "react-native-button": "1.7.1",
  "react-native-cached-image": "1.2.2",
  "react-native-camera-kit": "4.0.1",
  "react-native-camera-roll-picker": "1.1.9",
  "react-native-contacts": "0.5.2",
  "react-native-fbsdk": "0.4.0",
  "react-native-fetch-blob": "0.10.0",
  "react-native-fs": "2.0.1-rc.2",
  "react-native-geocoder": "0.4.5",
  "react-native-image-crop-picker": "0.10.5",
  "react-native-image-resizer": "0.0.12",
  "react-native-nav": "1.1.4",
  "react-native-permissions": "0.2.5",
  "react-native-photo-view": "1.2.0",
  "react-native-router-flux": "3.37.0",
  "react-native-stripe": "1.2.1",
  "react-native-swipe-list-view": "0.3.1",
  "react-redux": "4.4.6",
  "redux": "3.6.0",
  "redux-storage": "4.1.1",
  "redux-storage-engine-reactnativeasyncstorage": "1.0.2",
  "underscore": "1.8.3"
}

Answer 1

Passing this getCircularReplacer function as a second parameter into JSON.stringify() will fix this error:

const getCircularReplacer = () => {
    const seen = new WeakSet();
    return (key, value) => {
    if (typeof value === "object" && value !== null) {
        if (seen.has(value)) {
            return;
        }
        seen.add(value);
    }
    return value;
    };
};

Then you can use it as follows:

JSON.stringify(circularReference, getCircularReplacer());
// {"otherData":123}