Benchmark: Promise vs Async Await(2)

Script Preparation code:

function executePromises() {
    const vals = [];
    Promise.resolve(1)
        .then((val) => {
            vals.push(val);
            return Promise.resolve(2);
        })
        .then((val) => {
            vals.push(val);
            return Promise.resolve(3);
        })
        .then((val) => {
            vals.push(val);
            return Promise.resolve(4);
        })
        .then((val) => {
            vals.push(val);
            return Promise.resolve(5);
        })
        .then((val) => {
            vals.push(val);
            return Promise.resolve(6);
        })
        .then((val) => {
            vals.push(val);
            console.log(vals);
        });
}

function executePromises2() {
    const vals = [];
    Promise.resolve(1)
        .then((val) => {
            vals.push(val);
            return 2;
        })
        .then((val) => {
            vals.push(val);
            return 3;
        })
        .then((val) => {
            vals.push(val);
            return 4;
        })
        .then((val) => {
            vals.push(val);
            return 5;
        })
        .then((val) => {
            vals.push(val);
            return 6;
        })
        .then((val) => {
            vals.push(val);
            console.log(vals);
        });
}

async function executeAwaits() {
    const vals = [];
    vals.push(await Promise.resolve(1));
    vals.push(await Promise.resolve(2));
    vals.push(await Promise.resolve(3));
    vals.push(await Promise.resolve(4));
    vals.push(await Promise.resolve(5));
    vals.push(await Promise.resolve(6));
    console.log(vals);
}

function executePromiseAll() {
    Promise.all([Promise.resolve(1), Promise.resolve(2), Promise.resolve(3), Promise.resolve(4), Promise.resolve(5), Promise.resolve(6)]).then(
        (vals, rej) => {
            console.log(vals);
        }
    );
}

Tests:

Promise Chain
executePromises();
Async Await
executeAwaits();
Promise.all
executePromiseAll();
Promise Chain normal
executePromises2();

Rendered benchmark preparation results:

Suite status: <idle, ready to run>

Previous results

Test case name	Result
Promise Chain
Async Await
Promise.all
Promise Chain normal

Fastest: N/A

Slowest: N/A

Latest run results:

Run details: (Test run date: one year ago)

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:135.0) Gecko/20100101 Firefox/135.0

Browser/OS: Firefox 135 on Windows

View result in a separate tab

Test name	Executions per second
Promise Chain	204986.5 Ops/sec
Async Await	197922.0 Ops/sec
Promise.all	18656.2 Ops/sec
Promise Chain normal	29457.3 Ops/sec

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

LLMs can make mistakes. Check important info.

Let's dive into the world of JavaScript microbenchmarks!

**What is being tested?**

The provided benchmark tests three different approaches to handling promises and asynchronous code in JavaScript:

1. **Promise Chain**: A traditional promise chain approach, where each `then` method returns a new promise, allowing for sequential execution.
2. **Async/Await**: An async/await approach, which simplifies the promise chain by using a more readable syntax.
3. **Promise.all**: A way to execute multiple promises concurrently and wait for all of them to resolve.

**Options compared**

In each test case:

* The number of promises in the chain or array is different (2 vs 6).
* One approach uses async/await, while others use traditional promise chaining.
* Each approach has a unique execution pattern: Promise Chain executes sequentially, Async/Await executes sequentially with await, and Promise.all executes concurrently.

**Pros and Cons**

1. **Promise Chain**
	* Pros:
		+ Simple to implement
		+ Easy to understand for beginners
	* Cons:
		+ Can be slow due to sequential execution
		+ Error handling can become cumbersome with nested `catch` blocks
2. **Async/Await**
	* Pros:
		+ More readable and concise syntax
		+ Easier to handle errors with try-catch blocks
		+ Faster execution compared to Promise Chain (due to compilation to native code)
	* Cons:
		+ May not be suitable for all use cases, especially those requiring complex promise chaining
3. **Promise.all**
	* Pros:
		+ Executes multiple promises concurrently, potentially improving performance
		+ Easy to handle errors with a single catch block
	* Cons:
		+ Requires an array of promises, which might not be suitable for all scenarios
		+ Can lead to unexpected behavior if not used correctly

**Special considerations**

In this benchmark, the `executeAwaits()` test case uses async/await, while others use traditional promise chaining. This highlights the trade-offs between readability, performance, and complexity in handling promises.

**Other alternatives**

If you'd like to explore other approaches, consider:

* **Cooperative scheduling**: A different concurrency model that allows developers to explicitly control execution order.
* **Micro-threads**: Lightweight threads that can be used to execute code concurrently without the overhead of full-fledged threads.
* **JavaScript worklets**: A new API for executing micro-batches of JavaScript code in parallel.

However, these alternatives are not directly comparable to the promise-based approaches tested here.

Related benchmarks:

Promise vs Async Await(2) (version: 0)

Comparing performance of: Promise Chain vs Async Await vs Promise.all vs Promise Chain normal

Created: 2 years ago by: Guest

Jump to the latest result

Promise Chain

Async Await

Promise.all

Promise Chain normal

Suite status: <idle, ready to run>

Fastest: N/A

Slowest: N/A

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