Benchmark: RXJS - simple if vs filter

HTML Preparation code:

<script src="https://unpkg.com/rxjs@^7/dist/bundles/rxjs.umd.min.js"></script>

Tests:

Simple if
const obs$ = rxjs.of({name: 'Test'}); obs$.pipe( rxjs.tap((user) => { if (user.name) { console.log(user.name); } })).subscribe();
Filter
const obs$ = rxjs.of({name: 'Test'}); obs$.pipe( rxjs.filter((user) => user.name), rxjs.tap((user) => { console.log(user.name); })).subscribe();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Simple if
Filter

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: 8 months ago)

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/139.0.0.0 Safari/537.36 Edg/139.0.0.0

Browser/OS: Chrome 139 on Mac OS X 10.15.7

View result in a separate tab

Test name	Executions per second
Simple if	462271.1 Ops/sec
Filter	436407.1 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 explain what's being tested.

**Benchmark Overview**

The benchmark compares two approaches for filtering an observable in RxJS: `tap` and `filter`. The goal is to measure the performance difference between these two methods on a simple observable creation.

**Script Preparation Code**

The script preparation code includes the inclusion of the RxJS library via a CDN link (`https://unpkg.com/rxjs@^7/dist/bundles/rxjs.umd.min.js`). This allows users to create an observable and perform operations on it using RxJS functions.

**Individual Test Cases**

There are two test cases:

1. **Simple if**: This test case creates an observable with a single element (`{name: 'Test'}`) and uses the `tap` function to log the `name` property of each element. The `tap` function is used instead of filtering the elements.
2. **Filter**: This test case creates an observable with a single element and uses both `filter` and `tap` functions. The `filter` function filters out elements that don't have a `name` property, and then the `tap` function logs the `name` property of the remaining elements.

**Pros and Cons**

* **Tap**: Pros:
	+ Simple to implement
	+ Can be used for side effects or logging
Cons:
	+ Doesn't filter out elements; it only logs those that pass a condition
	+ May not be efficient if you need to process all elements
* **Filter**: Pros:
	+ Efficiently filters out unwanted elements
	+ Allows for more complex filtering logic
Cons:
	+ More verbose than `tap`
	+ May require additional processing steps after filtering

**Other Considerations**

When choosing between `tap` and `filter`, consider the following:

* Do you need to process all elements or can you skip some?
* Are there side effects that need to be performed on each element (e.g., logging)?
* Is efficiency critical, or do you prioritize simplicity?

**Library: RxJS**

RxJS is a reactive programming library for JavaScript. It provides a set of operators and functions for working with observables, which are a fundamental concept in functional programming. In this benchmark, RxJS is used to create an observable and perform operations on it.

**Special JS Features/Syntax (not applicable)**

There are no special JavaScript features or syntaxes used in this benchmark that require explanation.

**Alternatives**

If you need to filter observables in RxJS, you can also use other operators like `switchMap` or `mergeMap`. However, the `filter` and `tap` operators are often the most straightforward choices for simple filtering needs.

Related benchmarks:

RXJS - simple if vs filter (version: 0)

Comparing performance of: Simple if vs Filter

Created: 3 years ago by: Guest

Jump to the latest result

Simple if

Filter

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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