moment VS async

To learn more about Moment.js, please visit their official website.

Ah, Moment.js, the guardian angel of date and time manipulation. Ever needed to format a date, calculate durations, or display something like "2 days ago"? Moment.js has got your back. It's a lifesaver for anything date and time-related, making it a must-have in your project, especially if you're into making your users feel like you really get them.

After hours of trying to figure out why Jekyll was still showing "Today" for a post I modified last week, I remembered that I am using the timeago filter from jekyll-timeago plugin. I was rendering the dates using {{ doc.last_modified_at | timeago }}. As you know, Jekyll is a static site generator, and it renders this as HTML at the time of build, and only then. This means any date rendered with timeago is hardcoded as is in the HTML and won't change until the next build. I switched all the dates to the "%-d %b %y" format for now. Might use moment.js in the future to get the timeago dates back.

moment: Handles date and time manipulations with ease. Learn more

For the longest time working with dates in JavaScript was a huge pain. That’s why libraries such as moment.js or date-fns are so popular. A lot of times I’d reach for these libraries when working with relative time formatting, but since late last year we’ve had pretty great browser support for the RelativeTimeFormat() method. In my mind, relative dates are just more visually appealing, especially for working with dates internationally. Dates like "5 days ago" or "in 2 months" are far more intuitive for users than 12/12/2023, or 03/11/2027. Folks in the US will see that as March 11, 2027, whereas the rest of the world will see that as November 03, 2027. What a nightmare.

İ am using moment js for a long time. You can check it also. https://momentjs.com/

We could control the DST flip by setting the test's input time to the appropriate time of year (summer/winter). However we couldn't control the timezone. We had to adjust the expected data in the test 🤢 using the same library which the production code used (momentjs).

8. Moment.js

This may sound a bit general but we can't forget about well-tought code. If we are using a lot of external dependencies, we can check if there aren't many lighter alternatives. Example? Some people are still using moment.js for date formatting. Why not use a lightweight 2kb alternative instead? Writing clean, organized and maintainable code won't give us a huge score boost but we are trying to save every byte of data, right? 😉

Well you could just install the async package which has lots of useful functions like mapLimit which will reduce the burden and only run a number in parallel.

Have you checked out the docs for the async library they are using?

Edit:2. What's a good library that takes care of common async patterns? (Something like async)

Async/await is certainly not promises. In fact it would be much better implemented without promises as I proposed here: https://es.discourse.group/t/callback-based-simplified-async...

I would even say that async/await is anti-promise, it takes the main functionality of promises, a caching layer for results and errors that allows you to add the code continuation later and elsewhere (which is a major footgun imo) and coerces the execution flow back to going on the next line and provided immediately at compile time which results in a cleaner flow but not as clean, stateless, efficient or functional as if you were to remove the promises completely. Having an additional caching layer and state machine around every asynchronous function call is quite inefficient.

The essence of async/await is not promises, it's the underlying javascript generator (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...) functionality combined with asynchronous code to stop and start the generator. It's the ability to pause and resume function execution based on asynchronous operations.

The promise functionality, the caching layer and state machine for results is basically sanitized away with async/await, it becomes dead-weight computation. The only benefit of promises in async/await code is being able to more easily interface with other promise laden code which you don't need once you have async/await and a library like https://www.npmjs.com/package/async for more complex cases.

Note that promises based async/await is also a mess of an implementation that breaks stack traces and needs to support tons of odd statement corner cases (basically anything that can return an object that could be a promise) whereas a continuation passing style async/await would be a much simpler implementation that would only apply to function calls and maintain stack traces. We get that stack trace support automatically because of the great work of whoever implemented javascript generators which seem to already carry stack traces across paused/resumed functions (if you don't wrap in promises).

The nodejs async module: https://github.com/caolan/async provides 2 similar methods, async.waterfall and async.series.

With async I'd simply use async.series().

I don't understand. Sure you could spawn a ton of processes, but things might be bogged down. There are utilities out there for doing work queues.... so only N workers are running at any one time. The async library has some utilities for that. https://github.com/caolan/async

The documentation of asyncjs is quite straightforward and easy to read. As we've only seen a couple of use cases in this article, I'd recommend to go the asyncjs documentation and check out other possibilities with the library. You can also try to replicate the same using async/await to solidify your understanding of where the library might still make sense.

It basically was tons and tons of callbacks. They'd nest weirdly deep and be a pain to work with. If you're curious, here's a link to one of my favorite JavaScript libraries from those days - it gave you a bunch of neat utilities for dealing with async code.

api(function(result){ api2(function(result2){ api3(function(result3){ // do work }); });}); Which I could use a library like async for anyway, with something like: