Error: Cyclic object value in Next.js: Causes and How to Fix

Error: Cyclic Object Value in Next.js

Cyclic references occur when an object is directly or indirectly referencing itself. In JavaScript, when you attempt to convert or process such objects using certain methods like JSON.stringify, it results in the "Error: cyclic object value." This error can occur in Next.js during data fetching or state management. Understanding the behavior of cyclic references is crucial for preventing and handling these headaches.

Characteristics of Cyclic Object Values

• **Self-Referencing Nature**: An object contains properties that create a path leading back to the initial object, forming a cycle.

 

• **Unserializable**: JavaScript methods like `JSON.stringify` cannot process these objects due to their recursive nature.

 

• **Interruption in JSON Conversion**: Cyclic references interrupt functions that rely on a complete JSON conversion of an object.

Common Use-cases and Implications

• **Data Fetching in Next.js**: While using `getServerSideProps` or `getStaticProps`, fetching data that inadvertently contains cyclic structures leads to this error upon JSON serialization.

 

• **State Management**: Managing state with frameworks like Redux or Zustand that might contain unserializable values inadvertently creates cyclic references, disrupting entire application state flow.

Example Scenario

Imagine a situation where you're working with a deeply nested JavaScript object, and one of its properties inadvertently references a parent object:

const obj = {};
obj.a = {
  b: obj  // creates a cyclic reference
};

JSON.stringify(obj);
// This will throw an "Error: cyclic object value"

Understanding the Impact

• **Application Performance**: These errors can hinder server-side rendering (SSR) processes by blocking data serialization, degrading performance.

 

• **Data Integrity**: Causes potential data integrity issues as the expected JSON output may not be generated properly, resulting in loss or misinterpretation of information.