Benchmark: Another Object.assign vs spread operator

Tests:

Object.assign
var params = { open: true, onToggle: { mockConstructor() { }, mock() { }, mockClear() { }, mockReset() { }, mockRestore() { }, mockReturnValueOnce() { }, mockResolvedValueOnce() { }, mockRejectedValueOnce() { }, mockReturnValue() { }, mockResolvedValue() { }, mockRejectedValue() { }, mockImplementationOnce() { }, mockImplementation() { }, mockReturnThis() { }, mockName() { }, getMockName() { } }, children: { type: 'div', key: null, ref: null, props: { children: 'children' }, _owner: null, _store: { } }, dataTrackClick: 'dataTrackClick', dataTrackId: 'dataTrackId', noBodyScroll: true }; var other = Object.assign({}, params, { open: false });
spread operator
var params = { open: true, onToggle: { mockConstructor() { }, mock() { }, mockClear() { }, mockReset() { }, mockRestore() { }, mockReturnValueOnce() { }, mockResolvedValueOnce() { }, mockRejectedValueOnce() { }, mockReturnValue() { }, mockResolvedValue() { }, mockRejectedValue() { }, mockImplementationOnce() { }, mockImplementation() { }, mockReturnThis() { }, mockName() { }, getMockName() { } }, children: { type: 'div', key: null, ref: null, props: { children: 'children' }, _owner: null, _store: { } }, dataTrackClick: 'dataTrackClick', dataTrackId: 'dataTrackId', noBodyScroll: true }; var other = { ...params, open: false };

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Object.assign
spread operator

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 4 years ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:75.0) Gecko/20100101 Firefox/75.0

Browser/OS: Firefox 75 on Mac OS X 10.15

View result in a separate tab

Test name	Executions per second
Object.assign	1429587.1 Ops/sec
spread operator	2100775.5 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and explain what's being tested, compared, and their pros and cons.

**Benchmark Overview**

The benchmark is comparing two ways of creating an object with `open` property: using `Object.assign()` and the spread operator (`{ ...params, open: false }`). The test aims to measure which approach is faster in a specific JavaScript context.

**Options Being Compared**

1. **Object.assign()**: This method takes two arguments - the source object and the target object - and copies properties from the source object to the target object.
2. **Spread Operator (Rest Spread Syntax)**: This syntax allows you to create a new object by spreading an existing object's properties into a new object.

**Pros and Cons**

1. **Object.assign()**:
	* Pros:
		+ Widely supported across browsers.
		+ Easy to read and understand for developers familiar with the method.
	* Cons:
		+ Can be slower due to function call overhead and property lookup.
2. **Spread Operator (Rest Spread Syntax)**:
	* Pros:
		+ Typically faster than `Object.assign()` since it avoids function calls and property lookups.
		+ More concise and expressive code, making it easier to read and write.
	* Cons:
		+ Requires support for the syntax, which might not be present in older browsers.

**Other Considerations**

* The benchmark uses mock data to simplify testing. In a real-world scenario, you would need to consider other factors like object size, property count, and data type (e.g., primitive vs. reference types).
* The test assumes that the JavaScript engine being tested is already initialized and ready for execution.

**Library/Function Used**

None explicitly mentioned in the provided code snippet. However, both `Object.assign()` and the spread operator rely on the `Object` prototype methods (`assign()`) and the syntax features of the JavaScript language (Rest Spread Syntax).

**Special JS Feature/Syntax**

The benchmark uses Rest Spread Syntax, which is a modern JavaScript feature introduced in ECMAScript 2015. It allows you to create new objects by spreading existing object properties into a new object.

**Alternative Approaches**

Other ways to achieve similar results could include:

1. Using `Object.create()` and `Object.assign()`.
2. Utilizing `Array.prototype.slice()` and then creating a new object using `Object.assign()`.
3. Employing other custom solutions, such as writing a low-level JavaScript function to create objects.

Keep in mind that these alternative approaches might not be as efficient or readable as the spread operator, making it less suitable for most use cases.

Let me know if you have any further questions!

Related benchmarks:

Another Object.assign vs spread operator (version: 0)

Comparing performance of: Object.assign vs spread operator

Created: 5 years ago by: Guest

Jump to the latest result

Object.assign

spread operator

Suite status: <idle, ready to run>

Experimental features:

Fastest: N/A

Slowest: N/A

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