Update promise usage example for clarity

[collinsnji]

Description

Some edits to the promises examples to highlight the differences in the bad code example vs the good code example. PR addresses issue: #29743. Here's a summary of the changes

• Clarifies the difference between the good promise examples vs the bad example related to return statements in the arrow function
• Minor grammar and punctuation changes.

Motivation

Looking at the code examples for the promises, it is not exactly clear what makes a good promise call different from a bad promise call when considering the return statement. To avoid floating promises and race conditions, promises should always be returned either implicitly or explicitly, and this PR changes highlights that need. Changes will help the reader know that promises can have unexpected behavior if not properly returned.

Additional details

N/A

Related issues and pull requests

Fixes: #29743
Fixes #29742
Fixes #28236

[Josh-Cena]

Thanks, I will review this in the coming days, because there are a few other issues I want to address. I will edit this PR directly.

[github-actions]

Preview URLs

• /en-US/docs/Web/JavaScript/Guide/Using_promises

(comment last updated: 2023-11-23 07:08:23)

[Josh-Cena]

Hi, thanks for the PR! For posterity, I made the following modifications:

1. I added a very simple example of how you may stub the functions for experiments.
2. I added correct counterparts for the incorrect examples.
3. I added async/await versions of the examples, something I've been wanting to do for a while.
4. I removed the "Common mistakes" section because it just restates the things already said in other places.
5. I reordered the headings a bit to make it look more logical.

I have made substantial edits myself, but because I've already made this PR stall a while, I'll take liberty and merge it myself. If other reviewers find mistakes afterwards, I'll be happy to review a follow-on.