Bower! Unlimited Bower!

Sunday, February 1, 2015 · 6 min read

Bower. RequireJS. JamJS. Browserify. JQuery, Underscore, Lodash, and did I mention JQuery? Angular, D3, Polymer, Flux, Ember.js, Backbone, React, Dojo, Mootools, Bootstrap, Foundation, Meteor, Socket.io, Aurelia, Express.

What do all of these have in common?

For one, the fact that even though I’ve been using JavaScript for several years, having written thousands of lines of code used by hundreds of people, I have never used any of them. I don’t know any of their APIs. To date, every website I’ve written was hand-coded, starting from blank HTML file. And a lot of people frown upon that.

“Computers are all about automation,” you say, “There’s no good reason to impose the drudgery of boilerplate upon yourself. You’ll end up writing lots of duplicate code.”

Which is partly true. What you fail to mention is that I’d be writing plenty of duplicate code anyway. Consider, for instance, the XMLHttpRequest API. Each reimplementation of XHR is basically the same thing, with slightly different method names or argument conventions. As a developer, I would rather know the Real API—I can use it anywhere I want, and I have unrestricted access to the entire API (so I’m not at the mercy of someone who doesn’t think PUT requests are worth implementing).

Each new “web technology” has its own Wiki, API doc and “getting started” page which you need to somehow absorb ideas from. They have their own strange installation rituals, their own vocabulary, their own “best practices”, and their own encyclopedia of StackOverflow answers that you must read if you have any hope of getting stuff done.

Worse, though: they try to influence how you design.

All these “platforms” advertise themselves as “frameworks”. They force you to structure a project so that it conforms with the architecture that they want. They’re monoliths, and they don’t like cooperating with other monoliths.

That’s a horrible way to do web design. If PHP hammers have a claw on each end, then JS hammers are actually disguised combined harvesters that accept callbacks.

The first part of the problem is pedagogical in nature. To someone who is just beginning to learn web development, being introduced to a monstrous framework can lead to all sorts of misconceptions. jQuery is not a programming language. JavaScript can change the color of text on its own.

Students begin to learn from a higher level of abstraction than is necessary. Filling in the blanks by copy-pasting lots of boilerplate code is not computer science. You should know why you’re using a tool. Experience should come before abstraction.

The other part of the problem is more practical.

These architectures look shiny in contrived demo situations (name a modern-day language that does not boast of a beautiful “hello-world” scenario), but in the real world, their abstractions almost immediately begin leaking. You end up writing patches to tide over important features marked “TODO” on Github. You end up writing glue code, which is far worse than “the drudgery of boilerplate”.

Which isn’t to say you shouldn’t be using—or writing—JavaScript libraries. But you should be writing small, self-contained modules that provide a clean interface that is optimized for communicating with other programs. You should be using conventional vocabulary and idioms everywhere (even if those idioms smell like the dead fish that is JavaScript semantics). Don’t build a cathedral if you can get things done with a stall at the bazaar.

Your programs should do one thing, and do it well. It could be a small thing or a big thing. It could be a color picker widget or a library to encode PDF files. It doesn’t matter. It should be self-contained and present itself as a tool. Programmers should control code; code shouldn’t control programmers.


How?

Avoid side effects. The vast majority of your functions should take inputs and return an output. Things that change state should be limited as much as possible, and should always do so because the end-user explicitly mandated it. The moment you start messing about with global prototypes and settings, or pushing to arrays you didn’t create, you’re going to end up taking over the entire application.

Namespace. Your library should expose one name. One. window.something = {}. That’s it. Everything you expose should be a property of the window.something object. (No, window.something cannot be a function, that’s cute but annoying in practice.) npm enforces this, and if you’re clever, you can write code that’s a valid npm module and browser-worthy module. Read about IIFE if you’re confused.

Don’t force callbacks. If it doesn’t actually do anything asynchronous, don’t add a callback. Just return the answer. That’s what the return keyword is for.

Put thought into your argument convention. If your functions are generally monadic or dyadic, just accept positional arguments. Yes, it’s ok to write code like:

function (a, b) {
    doSomethingWith(a || "default", b || "default");
}

and yes, it’s ok to have users call a function with function(null, "cow") to default a positional argument that isn’t the last.

Avoid the arguments keyword like the plague. If you need variadicity, accept an array as an argument. Variadicity causes confusion. And people who get addicted end up writing functions that do different things depending on how many arguments were passed. Scary, scary, scary.

It’s also perfectly ok to accept just one argument, an object, if you need a dozen keyword arguments.

Be quiet. When your library runs in production, nobody should notice it. No console messages or “warnings”, no twiddling with the DOM to include a little banner.

Documentation is not advertisement. Once I’ve committed to using your library, you don’t need to continue explaining how it’s a revolution in generative fluid modern flat reactive magical material-inspired skeuomorphic silky-smooth user interface. Just tell us how to use the primitives. If there are concepts to be learned before using your library, explain them outside the API reference.

If you’re strictly on nodejs, prefer the provided Streams to whatever homegrown thing you’re inventing right now. Streams are tempting to reinvent-the-wheel, because they’re a pretty idea which isn’t terribly difficult to implement with your own shiny interface. Don’t do it. This extends to other things, too: XHR wrappers, querySelector reimplementations, and event-emitting architectures are just a few of the major offenders.

Document bugs. No, I won’t lose faith in your module if there’s a one-in-a-million corner case as long as it’s documented. I will lose faith if there’s a one-in-a-zillion corner case whose only documentation is a comment saying “ill fix thiss l8r”. Similarly, don’t introduce undocumented features. At the very least, say “this feature is experimental and SHOULD NOT be used in production”.

Don’t force dot-chaining. Yes, it’s useful in some places. Dot-chaining is great for transforming values in a sequence. It makes no sense when there are sequential actions that have side-effects. JavaScript has built-in support for that kind of thing: it’s called the semicolon (;).

Bad:

element
    .turnRed()
    .then()
    .ifYouFeelLikeIt()
    .and()
    .theStarsAlign()
    .changeSize()
    .do()

Good:

element.turnRed();
if (element.youFeelLikeIt && element.theStarsAlign) {
    element.changeSize();
}

Good:

data
    .map(transformation)
    .filter(selection)
    .reduce(action)

The problem with dot-chaining is that it locks a lot of important functionality behind weird objects.

Stop creating boilerplate creators. If you’re embarking on a new million-dollar company, you want to start from scratch and do things right, making sure you understand everything on your website. If you’re writing a toy demo for a 24 hour hackathon, you don’t need a full-featured MVC framework. You need to learn CSS.

Corollary: throwing Bootstrap at a problem doesn’t fix it. Bootstrap causes slow, janky websites. There was a time when it was shiny. Now it’s dull and mundane. Put some effort into making your website look like “yours”. And remember, there’s absolutely nothing wrong with the default OS-provided buttons that designers at Apple have spent ages perfecting. For that matter, I feel there’s nothing wrong with Times New Roman. It’s just that everyone feels the need to show that they know how to change the font face.

Don’t write generic CSS. Are you creating a set of pretty text box widgets? Don’t touch anything that doesn’t have class pretty-text-box. Things that go around setting global properties (even ones that should be set, like box-sizing) are evil. Don’t be that guy.

Write generic CSS. I might want to change the width of your syntax-highlighting gutter. Don’t make me edit your source code for that to happen.

Don’t build plugin infrastructures. Your code should be organized enough for people to write helpers themselves. You shouldn’t need to provide methods to “register” an “extension”. It almost always implies you’re building a cathedral.


The TL;DR version of this is that your code should be designed to cooperate with others. People don’t want frameworks to lock up all their hopes and dreams in. They want small, useful tools so that they don’t have to think about too many details.

UNIX wouldn’t work if it wasn’t made of hundreds of awesome tiny programs. The Internet should take a hint from that.

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