Let's break down the provided benchmark and explain what's being tested.

Benchmark Definition JSON

The benchmark defines a set of test cases to compare different approaches for creating a deep clone of an object. The object, MyObject, is defined with various properties, including a nested object jayson. This object contains two relevant properties: stringify and parse, which are related to the JSON serialization and deserialization process.

Test Cases

There are five test cases:

1. Lodash: Uses the _cloneDeep function from the Lodash library to create a deep clone of MyObject.
2. Custom Function: Implements a custom function, recursiveDeepCopy, to create a deep clone of MyObject.
3. JSON.parse: Attempts to create a deep clone by parsing the JSON representation of MyObject using JSON.stringify and then parsing the result back into an object.
4. structuredClone: Uses the structuredClone function, introduced in modern browsers (including Safari 15), to create a deep clone of MyObject.
5. Simple: Creates a shallow copy of MyObject by simply using the spread operator ({...}).

Options Comparison

The test cases compare the performance of different approaches:

• Lodash vs Custom Function: Lodash is generally faster and more efficient due to its optimized implementation, while the custom function requires manual iteration and branching.
• JSON.parse vs structuredClone: structuredClone is designed for deep cloning objects and is likely to be faster than using JSON.parse. This is because structuredClone avoids the need to serialize and deserialize the object, whereas JSON.parse involves converting the object to a string, parsing it, and then converting it back to an object.
• Custom Function vs structuredClone: The custom function requires manual implementation of recursive copying, while structuredClone is a built-in function optimized for deep cloning objects.

Pros and Cons

Here are some pros and cons associated with each approach:

• Lodash:
  • Pros: Fast, efficient, and well-tested.
  • Cons: Requires including an additional library (Lodash).
• Custom Function:
  • Pros: No dependencies, easy to understand for developers familiar with recursion.
  • Cons: Requires manual implementation of recursive copying, can be slower due to the overhead of function calls.
• JSON.parse:
  • Pros: Easy to implement, no additional dependencies required.
  • Cons: Slower than structuredClone and Lodash due to serialization and deserialization overhead.
• Structured Clone:
  • Pros: Fast, efficient, and optimized for deep cloning objects. Available in modern browsers.
  • Cons: Limited support for older browsers.

Library Usage

In this benchmark, the following libraries are used:

• Lodash (for its _cloneDeep function)
• None (the custom function does not rely on any external libraries)

Special JavaScript Features

The benchmark utilizes the structuredClone function, which is a relatively new feature introduced in modern browsers. It allows for creating deep clones of objects without requiring serialization and deserialization.

Overall, this benchmark provides insight into the performance differences between various approaches to deep cloning objects in JavaScript, highlighting the trade-offs between using built-in functions like structuredClone, Lodash, or implementing custom solutions.