An author of an open source project may do what they want, including using emoji in documentation like this.
On the flip side, I would never allow that code to be used in any of my projects, nor would I want to work with any contributors that think it is a "good" practice (nevermind "best"). To my mind, this documentation screams "unprofessional". I would be embarrassed to show it to any of my customers.
The code is not be the only thing by which a project should be judged. Bad documentation is worse than no documentation, because the author had a choice about the format and style that will be used. This project chose... poorly.
I have a rant about "object emojis" and "feelings emojis". The short version is: using emojis to express emotion is great, using them to talk about objects sucks. This documentation is using them to talk about objects, which sucks. In those cases either you have to parse them mentally, or read every word they replace twice (like in that documentation). It's bad. We have a thing to talk about objects in text: text. Words, letters, stuff like that.
"Feeling emojis" are great because they emulate non-verbal communication. A smile is a smile, a thumbs up is a "hm" or "okay". Text communication is by nature asynchronous so we have to find ways to cope with that. On the other hand, documentation doesn't need non-verbal communication.
Of course, some emojis can be used for both verbal and non-verbal communication. But stuff like burger? Or cashier? I don't see the point.
Another thing: this is possibly the worst explanation about concurrency and async/await I've ever read.
Aren't emojis supposed to replace words, kind of like abbreviations? What's the point of having a word and an emoji that mean the same thing right next to each other? I would never write, "want a hamburger :hamburger:?" Instead, I would just write, "want a :hamburger:?" This just seems like the worst of both worlds.
EDIT: HN doesn't seem to support emojis. Changed to a markdown like format instead.
here's the relevant documentation part in context https://fastapi.tiangolo.com/async/#concurrent-burgers who writes this stuff? who writes "your crush [Heart Eyes Emoji]" not just once but over and over, in documentation for a project? could easily just say "your friend [no emoji]"
I assumed from reading the excerpt in the github issue that each emoji represented an actor or asynchronous action to make it obvious which parts of the story corresponded to technical concepts, but the documentation wasn't 100% consistent on this. When it got to discussing parallelizing actions, it was easy to represent multiple bank tellers with emoji. I can see how it would be very off-putting, though.
I respect the usage of a couple of them in something like that even if I haven't (and I won't), but that overuse is like the late 90s gifs in personal websites, not only looks unprofessional, but also difficult the reading of the document.
Maybe I'm just an old man yelling at clouds, but I always found the use of emoticons and emoji in official documents extremely off putting. If you want to look hip and cool, at least do so only where appropriate - public-facing technical documentation needs to be articulate and maximally accessible.
Not to mention how inconvenient it is to actually add emoji. Chances are that the person who wrote that page didn't draft it from a phone with an easily accessible emoji keyboard, nor from a physical keyboard with emoji bindings. So they'd have to go out of their way to open up an on-screen emoji keyboard, or an emoji webpage, and paste those emojis one by one.