This benchmark evaluates and compares the performance of two methods for creating deep copies of JavaScript objects: JSON.stringify combined with structuredClone, and structuredClone directly. Let's break down the components and considerations of this benchmark.

Options Compared

1. Benchmark Method: JSON.stringify with structuredClone

   • Code: myCopy = structuredClone(JSON.stringify(MyObject));
   • This approach first converts the MyObject into a JSON string using JSON.stringify and then uses structuredClone to create a deep copy of that string.

2. Benchmark Method: structuredClone Directly

   • Code: myCopy = structuredClone(MyObject);
   • In this method, structuredClone is called directly on the MyObject, taking advantage of its built-in functionality for deep copying.

Pros and Cons of Each Approach

JSON.stringify with structuredClone

• Pros:
  • It can handle basic types, but its primary purpose is serialization (i.e., converting an object to a string).
  • It can convert objects to JSON string format which can be useful for data transmission (e.g., over networks).
• Cons:
  • It cannot clone non-serializable types (like functions, undefined, symbols, etc.).
  • Involves an unnecessary conversion to string and then back to an object, which is less efficient in terms of performance compared to direct cloning.
  • Increases complexity with an extra layer of processing, which could introduce performance overhead.

StructuredClone Directly

• Pros:
  • Designed specifically for deep copying JavaScript objects, it supports a wider variety of types, including arrays, objects, and certain special types like Date and Map.
  • More efficient as it avoids the intermediate step of serialization to JSON, leading to better performance in terms of execution speed.
• Cons:
  • It may not serialize objects to string, which is sometimes needed for data interchange protocols.
  • As of now (October 2023), browser support for structuredClone is generally good, but it's always wise to check compatibility for older browsers.

Other Considerations

• Browser Support: While modern browsers (like Chrome) support both methods, developers should be aware of how each method behaves on older browsers. JSON.stringify is more widely supported but also less efficient for deep cloning.
• Use of Libraries: Neither of the methods uses any third-party libraries but are built-in features of the JavaScript language. However, should you need additional functionality for deep cloning, libraries like lodash.cloneDeep are commonly used in practice as they provide additional features and handle edge cases that both methods may not address.

Alternatives

• Lodash's cloneDeep: A popular utility library that provides a cloneDeep method capable of deeply cloning any JavaScript object efficiently, handling many edge cases and data types.

• Manual Deep Copying: Implementing a custom solution by recursively copying object properties can be an alternative but often leads to complications, especially with circular references and complex types.

Conclusion

This benchmark clearly demonstrates the performance differences between JSON.stringify and structuredClone. For the specific task of deep cloning, structuredClone is the more effective and efficient choice, while JSON.stringify, although useful in other contexts, introduces unnecessary overhead when used solely for deep copying. Software engineers, regardless of their familiarity with JavaScript, are encouraged to consider the appropriate use cases, performance implications, and limitations of each method when deciding which to utilize.