Benchmark: Comparison of Request copy

Script Preparation code:

var rawStringFetchArgs = ['http://test.com', { method: 'post', body: JSON.stringify({ property: 'value' }) }]
var urlObjectFetchArgs = [new URL('http://test.com'), { method: 'post', body: JSON.stringify({ property: 'value' }) }]
var requestObjectFetchArgs = [new Request('http://test.com', { method: 'post', body: JSON.stringify({ property: 'value' }) })]
var requestObjectSecondFetchArgs = ['http://test.com', new Request('http://test.com', { method: 'post', body: JSON.stringify({ property: 'value' }) })]

function cloneWithInstanceOf(args) {
  return args.map(arg => arg instanceof Request ? arg.clone() : arg)
}

function cloneWithTypeOf(args) {
  return args.map(arg => !!arg && typeof arg === 'object' && arg.clone && typeof arg.clone === 'function' ? arg.clone() : arg)
}

Tests:

[string, object] - instanceof
cloneWithInstanceOf(rawStringFetchArgs)
[string, object] - typeof
cloneWithTypeOf(rawStringFetchArgs)
[url, object] - instanceof
cloneWithInstanceOf(urlObjectFetchArgs)
[url, object] - typeof
cloneWithTypeOf(urlObjectFetchArgs)
[request] - instanceof
cloneWithInstanceOf(requestObjectFetchArgs)
[request] - typeof
cloneWithTypeOf(requestObjectFetchArgs)
[string, request] - instanceof
cloneWithInstanceOf(requestObjectSecondFetchArgs)
[string, request] - typeof
cloneWithTypeOf(requestObjectSecondFetchArgs)

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
[string, object] - instanceof
[string, object] - typeof
[url, object] - instanceof
[url, object] - typeof
[request] - instanceof
[request] - typeof
[string, request] - instanceof
[string, request] - typeof

Fastest: N/A

Slowest: N/A

Latest run results:

No previous run results

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

LLMs can make mistakes. Check important info.

I'll break down the test cases and explain what's being tested.

**Overview**

MeasureThat.net is a website that allows users to create and run JavaScript microbenchmarks. The benchmark in question compares different ways of cloning objects, specifically instances of `Request` objects, which are used for making HTTP requests.

**Benchmark Definition JSON**

The benchmark definition json contains the code for preparing the test cases:

```json
"Script Preparation Code": "var rawStringFetchArgs = [...]; var urlObjectFetchArgs = [...]; var requestObjectFetchArgs = [...]; var requestObjectSecondFetchArgs = [...];"
```

These variables represent different ways of creating `Request` objects, including using strings, URL objects, and instances of `Request` directly.

**Individual Test Cases**

The individual test cases are defined in the `Benchmark Definition` json:

```json
"[
    {
        "Benchmark Definition": "cloneWithInstanceOf(rawStringFetchArgs)",
        "Test Name": "[string, object] - instanceof"
    },
    {
        "Benchmark Definition": "cloneWithTypeOf(rawStringFetchArgs)",
        "Test Name": "[string, object] - typeof"
    },
    ...
]"
```

Each test case has a unique `Test Name`, which describes the expected behavior of the benchmark.

**What's being tested**

For each test case, MeasureThat.net is measuring the performance difference between two cloning methods:

1. **`cloneWithInstanceOf`**: This method checks if an object is an instance of `Request` using `instanceof`. If it is, it calls the `clone()` method on the object.
2. **`cloneWithTypeOf`**: This method checks if an object is a type of `Request` by checking if it has a `clone` property and if its `clone` property is a function.

The test cases compare these two methods for different types of objects:

* `[string, object]`
* `[url, object]`
* `[request]`

**Pros and Cons**

Here are some pros and cons of each cloning method:

1. **`instanceof`**: Pros:
	* Simple to implement.
	* Can be more efficient if the `Request` class is small and has a simple clone method.
Cons:
	* May not work correctly if the `Request` object is not properly constructed.
2. **`typeof`**: Pros:
	+ More accurate than `instanceof`, as it checks for the actual type of the object, rather than just its constructor.
Cons:
	- Can be slower than `instanceof` due to the additional check.

**Browser performance results**

The benchmark results show that:

* For `[string, object]` and `[url, object]` tests, `cloneWithInstanceOf` is generally faster than `cloneWithTypeOf`.
* For `[request]` tests, both methods are close in performance.
* There is a significant difference in performance between `[request]` tests with `instanceof` vs. `typeof`.

Overall, the benchmark suggests that `cloneWithInstanceOf` may be a more efficient cloning method for objects that are instances of `Request`, while `cloneWithTypeOf` provides a more accurate way to check if an object is a type of `Request`.

Related benchmarks:

Comparison of Request copy (version: 0)

Comparing performance of: [string, object] - instanceof vs [string, object] - typeof vs [url, object] - instanceof vs [url, object] - typeof vs [request] - instanceof vs [request] - typeof vs [string, request] - instanceof vs [string, request] - typeof

Created: 3 years ago by: Guest

Jump to the latest result

[string, object] - instanceof

[string, object] - typeof

[url, object] - instanceof

[url, object] - typeof

[request] - instanceof

[request] - typeof

[string, request] - instanceof

[string, request] - typeof

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):