Benchmark: JavaScript spread operator vs Object.assign performance with new error

Tests:

Using the spread operator
const firstObject = new Error('Network Error!') const result = { ...firstObject, statusCode: '123' };
Using Object.assign
const result = Object.assign(new Error('Network Error!'), { statusCode: '123' });

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Using the spread operator
Using Object.assign

Fastest: N/A

Slowest: N/A

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Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):

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

**Benchmark Overview**

The test measures the performance difference between two approaches: using the spread operator (`...`) to merge objects, and using `Object.assign()` with an error object as one of its arguments.

**Options Compared**

Two options are compared:

1. **Using the spread operator**: This approach uses the spread operator (`...`) to create a new object that includes all properties from another object (in this case, an `Error` object). The resulting object also includes additional properties set explicitly.
2. **Using Object.assign()**: This approach uses the `Object.assign()` method to merge two objects together. In this test, one of the objects is an error object created with `new Error('Network Error!')`.

**Pros and Cons**

* **Using the spread operator:**
	+ Pros:
		- Can be more concise and readable when merging simple objects.
		- Creates a new object without modifying the original.
	+ Cons:
		- May have performance implications due to the creation of an additional object.
		- Can lead to unexpected behavior if not used carefully (e.g., when using null or undefined values).
* **Using Object.assign():**
	+ Pros:
		- Efficient and optimized by JavaScript engines for merging objects.
		- Avoids creating unnecessary intermediate objects.
	+ Cons:
		- May be less readable due to its functional programming style.

**Library and Special JS Features**

In this test, the following libraries or features are used:

* None

**Special JS Feature/Syntax**

There is no special JavaScript feature or syntax being tested in this benchmark. However, it's worth noting that using `new Error()` with a string message can be considered as creating a custom error object.

**Other Alternatives**

Some alternative approaches to merging objects could include:

1. **Destructuring**: Instead of using the spread operator or `Object.assign()`, you could use destructuring assignment (e.g., `{ ...firstObject, statusCode: '123' }`) or the rest parameter syntax (e.g., `(..., { statusCode: '123' }) => ({ ...firstObject, statusCode: '123' })`) to achieve the same result.
2. **Constructor functions**: You could create a custom constructor function that takes an object as an argument and returns a new object with the specified properties.

Keep in mind that these alternatives might have different performance implications or trade-offs compared to using the spread operator or `Object.assign()`.

Related benchmarks:

JavaScript spread operator vs Object.assign performance with new error (version: 0)

Comparing performance of: Using the spread operator vs Using Object.assign

Created: 4 years ago by: Guest

Jump to the latest result

Using the spread operator

Using Object.assign

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

No previous run results

Autogenerated LLM Summary (model llama3.2:3b, generated one year ago):