How Functional Programming Shaped and Twisted Front End Development

   arr.map().filter().filter().map()

   const x = arr.map()
   const y = x.filter()
   const z = y.filter()
   const d = z.map()

   const x = (arr) => arr.map()
   const y = (arr) => arr.filter()
   const z = (arr) => arr.filter()
   const d = (arr) => arr.map()
   
   o = d(z(y(x(arr))))

with a for loop it is easier to read initially but if that filter chain grows the functional approach will begin to be better.

Take an example of a for loop doing the same thing:

   const acc = []
   for (const x in arr) {
      y = map1(x)
      if(filter(y) {
         continue
      }
      z = y
      if(filter(z)) {
         continue
      }
      d = map2(z)
      acc.push(d)
    }

But I agree with you. Initially and not at scale, functional programming loses readability. Functional programming is harder to read because people think procedurally over functionally. We like numbered instructions or a todo list, not a series of composed function calls and thus from a general view point functional programming is harder to read than procedural programming. But this has never been the benefit of functional.

Functional programming is supposed to solve the modularity problem with how you organize programs to be reusable. Functional programming objectively does this while it is only subjectively considered less readable by the majority of people.

The real obsession with FP is the pervasive use of immutable state. But in apps, state must be effectively mutated, but now with a copy of the original immutable object. The FP obsession believes that this better than directly mutating the state each and every time.

The fact that you single out .reduce() here is really telling to me. .reduce() definitely has a learning curve to it, but once you're used to it the resulting code is generally much simpler and the immutability of it is much less error-prone. I personally expect JS devs to be on the far side of that learning curve, but there's always a debate about what it's reasonable to expect.

Only if that's how you were taught. For devs brought up in the FP manner, the for loop is as hard to grok as you find the chained stuff.

The Blub Paradox in action.

filter and map immediately tell me what the purpose of the loops are - filter things and transform things. A for loop does not do this.

To someone familiar with functional programming these are very normal and easier to read and grep than just a loop. In other words filter and map give additional context as to the intent of the loop, a bare for loop does not.

Not to mention this is not abnormal in languages outside of JS, even non-functional ones.

That said Ive seen too many convoluted uses of reduce that I just avoid it out of principle.

What you are expressing is that they are more familiar to you.

Nothing about map or filter makes them any more complex than a for loop, nothing.

At best they can be less familiar to a class of programmers.

It's interesting; when I'm writing JS in an actual .js file, I do tend to use for loops. But when I'm writing JS at the (CLI or browser-dev-console) REPL, I'll always reach for arr.map().filter().filter().map().

When you're at a REPL, with its single-line/statement, expression-oriented evaluation, it's always easier / more intuitive to "build up" an expression by taking the last expression from history, adding one more transformation, and then evaluating the result again to see what it looks like now. And you don't really want side-effects, because you want to be able to keep testing the same original line vis-a-vis those modifications without "corrupting" any of the variables it's referencing. So REPL coding leads naturally to building up expressions as sequences pure-FP transforms.

Whereas, when you're iteratively modifying and running a script, with everything getting re-evaluated from the start each time, it's not only more intuitive to assign intermediate results to variables, but also "free" to have side-effect-y code that updates those variables. It's that context where for loops become more natural.

I bet that a lot of the chained-expression JS code you see out there was originally built up at a REPL, and then pasted into a file, without then "rephrasing" it to be more readable/maintainable in the context of a code file.

...though there's also just FP programmers who write JS (or more often TS) as if it were a pure-FP language — either literally making every variable const / using Object.freeze / using Readonly<T>, or just writing all their code as if they had done that — where for loops become almost irrelevant, because they're only really for plain iteration (they're not list comprehensions), and plain iteration has few uses if you're not going to do anything that produces side-effects.

Also weak typing plays into this. Some operations not immediately raising an error when the wrong type of thing is provided, is a recipe for bad experience when having point free style or semi point free style. If given the choice, at least one thing would be good to have, strong typing or static typing.

It’s pretty great and hard to imagine going back to a React-like component hierarchy.

To avoid it, funny enough, you have to take cues from functional programming, and you need strong, composable, primitives with succint interfaces (the opposite of shadcn). Even for visually combining and placing components, you need stateless layout components [1] that don't depend on anything and just render children a certain way. This way it's possible to have a very flat component hierarchy. The entire state-logic at the top-level doesn't hurt much anymore. Also, just props+events are enough, no need for Context, Redux or other tricks.

But if you go the "Clean Code" route and the main reason to have components is so so they're not too big, then you get deep hierarchies, prop-drilling becomes a big problem, and you need Context or state libraries specifically for inter-component communication.

This is a problem that I've seen come up time and time again not only in Frontend but also in desktop apps and in video games. And backends often have the luxury of having the entire state in the database, so it doesn't happen as often.

Of course the side effect of this is that you will end up with bigger components, and you need better abstractions, but IMO this is a small price to pay for having code that is easier to work with and doesn't need special ways for handling the data. Also this method tends to work better in bigger apps and people complain it's wasteful in smaller apps, so there's that too.

[1] In the design world this is often called Templates. https://atomicdesign.bradfrost.com/chapter-2/#templates It's interesting how this didn't catch among frontend devs. I remember "layouts" being a big part of WPF for example.

My team migrated away from Redux and for over a year I’ve been unable to pinpoint why I’ve been longing for it again. This has hit the nail on the head for me. Redux (and other “global” state management solutions) allowed me to decouple the data graph from the UI graph. When a UI event is triggered, an action is dispatched and then the data graph takes over. This makes the UI graph extremely simple - render UI and dispatch actions - but these days we’re mixing state with business logic, event handling, API calls, rendering UI, styling, etc. This is very much a problem of our own making that could be solved by a different architecture, but yeah… thanks for clarifying this feeling for me.

when i use aurelia, then the whole page is one component and dynamic functionality in elements is achieved through bindings and functions that all share the data in the component. you can include other components, but you only do that where needed, and then passing data becomes a lot easier.

ORM keeps sucking because RDBMSes simply don't operate on objects. You can either impose ill conceived object models on the database, or try and fail to capture the database's affordances in objects.

I don't have a theory on what's gone wrong with front-end development to cause its chronic disease, but it may simply be that HTML is a document markup language, and makes a questionable base for a user interface.

Valid questions we should all be asking. Sometimes, just because “that’s the way it was” doesn’t mean that’s the way it should be. Often times I find myself deleting code that is now more readily available as either part of the platform I’m on or part of the framework I’m using.

Your points are valid too, that they don’t know about the history that got us here and why it is the way it is but nevertheless we should all be asking ourselves daily, “do we still need this?” and trim the fat.

I felt cheated just by having read the article: I'm all for a long and winding article that has something to say, but this one was telling a bad joke for WAY, WAY too many paragraphs.

And the only reason it suddenly reappeared in 2022 was because browsers want to get rid of alert/prompt dialogs.

The spec was (and probably still is) so riddled with issues that it never went anywhere for 10 or so years, and Chrome at one point argued it should be removed.

> This would be valid but the very MDN article they link literally starts with

People involved with HTMX play really fast and lose with anything that doesn't fit their conclusions hoping no one will call them out.

`<dialog>` only got full compatibility with Firefox about two months ago with Firefox 141. Safari still doesn't support `closedby`.

Given that, I still regard `<dialog>` as experimental, and that'll remain the case as long as the "Baseline Widely available" label comes with an asterisk.

Here's my take:

- The web was visualized as a way to publish academic documents in a hyperlinked document system. Librarians and academics live in this world. We hear the word "semantic" from them a lot.

- The visual web was visualized as a way to publish documents that had a precise look. Graphic designers live in this world. They don't care about semantics. They do care about pixel perfect layouts and cool effects.

- The web app was visualized as a way to deliver software to users with lazy, "click link to install"-like behavior. What this crowd cares about is providing server functionality to users, and other concerns like semantics or pixel perfect are often secondary.

- The single page web app is also visualized as as a way to deliver software to users with lazy, "click link to install"-like behavior. They differ from the web app group in that they try to have more server functionality right in the client. Again semantics and pixel perfect are secondary. App complexity is a big problem that this group contends with, and this is what the article discusses.

Given these different ways of visualizing the web (and I'm sure I've left a few out), it's no wonder that we're stuck with the mess that is today's web development. The right solution is a sensible runtime for app development, that doesn't force you to render UI through the DOM and doesn't make it hard for you to get access to basic things like the local file system. We've known this forever (anyone remember Flash?).

WASM feels like it might finally allow app developers to do all of the software things that native platform developers get to do easily, and with the added bonus of strong sandboxing. It's early days yet, I think the "Ruby on Rails"-moment has not yet arrived there yet, i.e. a very popular, easy way for devs to create whatever app-de-jour everyone's excited about.

Firstly, you can’t break what is already there, so any evolution of the general platform often has to make wider guarantees than a single framework.

Adopting ideas from any single framework too quickly may put you in a worse position. A framework can evolve and choose when to break compatibility, a language or platform standard has a tougher job in that regard.

Some things that front end frameworks have settled on are now being looked at for standardisation, but I’m personally still wary about changing something like the ecmascript for. It would be an easier call if there were a standard library which simply needed an implementation, but we aren’t quite there yet.

Because standards committees are also made out of people. They have their own agendas, experiences, biases, company loyalties etc.

And in the past ten or more years all standards have been taken over by a very small number of very prolific people from Google. Prolific as in: writing dozens and hundreds of specs and having their fingers in all standards.

In my view CSS is essential. Not knowing CSS at least somewhat well is a huge obstacle in producing high quality frontend work. It's like being a carpenter, but simply not knowing one important aspect of wood, or not being able to use a specific tool to work with wood, lets say a tool to smooth surfaces. CSS is part of the medium you work with as a FE engineer. It is unfathomable to me, how a FE engineer can not know this stuff well. If some FE engineer is reading this, and feels some impostor syndrome: Yes, if you don't know your medium and tools as least in the basics, then you should feel like an impostor.

I see broken responsiveness very often. Of course in almost all websites, that rely on JS to display what is essentially a bunch of static texts.

If I was interviewing for a FE position, and really had to go through the circus of asking interviewees code questions, I would definitely include a minimum of CSS knowledge there. Basic things like how they would scope their CSS to specific elements or classes of elements and how they would prevent their styling to bleed into other stuff. Or how they would set up a theme with just CSS. Not questions expecting them to write CSS on a whiteboard, of course. Just testing their basic understanding.

"my set of non-standard tools and preprocessors is superior to these guys' non-standard tools and preprocessors" is not a good argument.

> I find this reluctance to enforcing guidelines weird

Because CSS doesn't lend itself to any enforcement. All the tools that appear around it includng those you like like SASS and "some processing" don't appear because people don't understand something or can't enforce something.

> Of course, all this is under the hindsight knowledge that HTML and CSS have evolved in recent years to be truly powerful and versatile.

Indeed. And many of these features have been made available across all major browsers only in the past two or so years.

No one is going to rewrite everything from SASS or CSS-in-JS just because some features now exist in vanilla CSS.

CSS modules are really enough - there's no need to overthink it any further.

I'm currently in a project where my first task, spanning several months, was to clean up after the previous guy. The main issues in styling were misguided attempts at sharing styles implemented via breaking encapsulation.

Should they be allergic to punishing people? No, but it be how it do.

It's worse than that. All the hype in design has been about creating a global design language, and enforcing it over all your teams for more than a decade now. All the hype has been on centralizing the design team, moving it away from the developers for some years. All the hype has been on tools that claim to enable reusing and distributing that work...

And yet everything is done in a way that developers have to do everything themselves and don't get to coordinate with each other.

(Honestly, I'm settling on the opinion that non-developing application design is a scam all around.)