Benchmark: Object.freeze vs Object.seal (only property access)

Script Preparation code:

var normal = {
  x: 0,
  y: 0
};
var freeze = Object.freeze({
  x: 0,
  y: 0
});
var seal = Object.seal({
  x: 0,
  y: 0
});

Tests:

normal
if (normal.x + normal.y) throw new Error("Wrong");
freeze
if (freeze.x + freeze.y) throw new Error("Wrong")
seal
if (seal.x + seal.y) throw new Error("Wrong")

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
normal
freeze
seal

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 9 months ago)

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 18_5 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/18.5 Mobile/15E148 Safari/604.1

Browser/OS: Mobile Safari 18 on iOS 18.5

View result in a separate tab

Test name	Executions per second
normal	150711568.0 Ops/sec
freeze	181922976.0 Ops/sec
seal	303803968.0 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's break down the provided benchmark and its test cases.

**Benchmark Definition JSON**

The benchmark definition is a JSON object that contains information about the benchmark to be performed. It includes:

* `Name`: A unique name for the benchmark, which in this case is "Object.freeze vs Object.seal (only property access)".
* `Description`: An optional description of the benchmark, which is empty in this case.
* `Script Preparation Code`: A JavaScript code snippet that prepares the script to be executed. In this case, it defines three objects: `normal`, `freeze`, and `seal`, each with two properties (`x` and `y`) initialized to 0.

**Individual Test Cases**

The benchmark consists of three individual test cases:

1. **`normal`**: This test case checks if the sum of `x` and `y` in the `normal` object is non-zero using an `if` statement that throws an error if the condition is true.
2. **`freeze`**: Similar to the previous test case, but this time it uses the `Object.freeze()` method to seal the `freeze` object, which also has two properties (`x` and `y`) initialized to 0. The goal is to check how different browsers handle property access on a frozen object.
3. **`seal`**: Another similar test case that checks how browsers handle property access on an object sealed with `Object.seal()`.

**Options Compared**

In this benchmark, the following options are being compared:

* Using `Object.freeze()` vs using `Object.seal()`: Both methods prevent property assignment to an object's properties. However, `Object.freeze()` also prevents deletion of a property from the object, whereas `Object.seal()` only restricts assignment and addition of new properties.

**Pros and Cons**

Here are some pros and cons for each approach:

* **`Object.freeze()`**:
	+ Pros: Provides more protection against unwanted modifications to an object's properties.
	+ Cons: May be overkill if you only need to prevent property assignment, as it also prevents deletion of properties. Additionally, `Object.freeze()` can introduce performance overhead due to the additional checks performed on the object.
* **`Object.seal()`**:
	+ Pros: Provides protection against unwanted modifications to an object's properties while still allowing for some flexibility (e.g., deleting a property).
	+ Cons: May not be enough protection if you need to ensure that certain properties are always present or have specific values.

**Library Usage**

None of the provided test cases use any external libraries.

**Special JS Features/Syntax**

There is no mention of special JavaScript features or syntax in the benchmark definition or individual test cases.

**Other Alternatives**

Some alternative approaches could be:

* Using `Object.assign()` to prevent property assignment
* Using a library like Lodash's `freeze()` function to seal an object
* Implementing custom protection mechanisms using techniques like proxy objects or getter/setter functions

However, these alternatives are not being tested in this specific benchmark.

Related benchmarks:

Object.freeze vs Object.seal (only property access) (version: 0)

Comparing performance of: normal vs freeze vs seal

Created: one year ago by: Guest

Jump to the latest result

normal

freeze

seal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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