[BigJono]

Yeah and if you've analysed 100 sets of docs for 100 dependencies you've done a ton more work than writing 100 trivial functions.

Why does everyone in JS land treat dependencies like they're just some free magic, as if an intimate familiarity with the source code is injected into your entire team's brains the moment you type 'npm install'? I've worked with far too many people that blow out the package.json file for every little thing then wonder how every other dev on their team seems to be paralysed by the smallest task.

Every time someone on your team runs into a dependency boundary they need to stop reading code, pull up a browser, and start reading docs. You can't trace the path of execution through a black box dependency, which means if you use a bunch of them in one place your developers are going to have to hold a hell of a lot of information in their head while they analyse that code. If they drop something, it's back to the docs again. At the extreme, it's a context switching nightmare.

Dependencies cost time, effort and brain power. Make sure you're getting enough in return.

[jhall1468]

You're absolutely wrong. If reading the docs were harder/more work than writing the code we'd have 100s of implementations of lodash. Instead people use lodash.

Dependency boundary? If you can't figure out what a function called classNames does in the context of a React render function in which the output of classNames is put as a value in to "className" attributes, you need to find a new job.

Dependencies cost time, effort and brain power when they actually require those things. Be thoughtful when using something that actually requires investigation. But honestly, a trivial function should be self-documenting or it really isn't trivial, is it? If I had an npm library called array-flatten are you seriously going to read the docs, or assume it flattens nested arrays?

[BigJono]

I never said anything about writing the dependency. I'm talking about reading and writing code that uses it.

Of course it's easier to read a trivial function than the docs for a trivial function. That's what makes it trivial, it's not abstracting away anything meaningful. And of course I can easily figure out what classNames outputs.

You know what I can't figure out trivially? What inputs it takes. It's a polymorphic function. Me and Bob load up a new codebase, I open a few files and see classNames used a couple of times with an object parameter. I can now be pretty confident what the API of the function is. Bob opens up a couple of different files and sees it used with an array parameter a few times. Now he's pretty confident he's got the hang of it too. We both go off to write new components. I've got a bunch of this everywhere:

{ foo: true, bar: true, baz: true }

And Bob has a bunch of this everywhere:

[foo ? 'bar' : null, baz ? 'boop' : null]

Bam, inconsistent code. Could have easily been solved by reading the docs before using something though. And hey, at least we'll both remember for next time...

...Unless our team imports 100 of these libraries and tries to enforce a consistent use of them across the project.

There's only so much API surface area one dev can keep at the front of their mind while coding. Good devs understand this and minimize it. Bad devs pile in trivial dependencies because they don't understand their cost.

Oh, and how do I know whether flattenArray is recursive or not? What if it is and I only want to flatten one level? Does it take a second integer parameter? Or an options object? Since we're talking about JS, does it flatten Array-like objects? Is that the same API or a different one? It's almost like your example proves my point...

[jhall1468]

> Bam, inconsistent code

Yeah, and in CR you should be told not to use the object form when you have "true" as the value, as it's pointless. That's what string form is for. The "docs" are literally 5 lines where you learn you can send object literals, arrays and strings.

> There's only so much API surface area one dev can keep at the front of their mind while coding. Good devs understand this and minimize it. Bad devs pile in trivial dependencies because they don't understand their cost.

Yes, because if you implement a similar feature the remaining members of your team all know it through osmosis. The surface area of these functions is tiny, but apparently your implementation requires no investigation by anyone.

> Oh, and how do I know whether flattenArray is recursive or not?

Holy cow, man. Do you literally hand-implement EVERY utility function you've ever needed?

> It's almost like your example proves my point...

Your point seems to be: you can't manage to infer ANYTHING from a function signature AND that apparently somehow your team members can ALWAYS infer everything needed from any function YOU write.

Use code inspection and you'll never open the docs for flattenArray or anything like it again. If this is the amount of effort required for flattenArray for you, how to you actually use large libraries with HUGE surface areas?

[BigJono]

> Yeah, and in CR you should be told not to use the object form when you have "true" as the value, as it's pointless. That's what string form is for. The "docs" are literally 5 lines where you learn you can send object literals, arrays and strings.

What a dumbass argument. So instead of writing a one line abstraction, I should invest a bunch of CR time explaining to my whole team which of 3 different APIs they should be using in this dependency I've brought in?

> Holy cow, man. Do you literally hand-implement EVERY utility function you've ever needed?

No, just the trivial ones. Have you been actually reading this thread?

> Your point seems to be: you can't manage to infer ANYTHING from a function signature

No, my point is that you can't infer the full API of a function from the arguments passed to it's invokation when the function is polymorphic.

> AND that apparently somehow your team members can ALWAYS infer everything needed from any function YOU write.

If the function is trivial, which is exactly what we've been talking about this whole time, then No. Fucking. Shit. The function is trivial and they have the source code right there.

[jhall1468]

> So instead of writing a one line abstraction, I should invest a bunch of CR time explaining to my whole team which of 3 different APIs they should be using in this dependency I've brought in?

It's not a one-liner because it doesn't support the same feature set. It supports a basic use case that may be great for trivial apps, but in the real world it isn't.

> No, just the trivial ones. Have you been actually reading this thread?

And said trivial ones must still be "learned" by your co-workers. You've saved exactly zero time.

> No, my point is that you can't infer the full API of a function from the arguments passed to it's invokation when the function is polymorphic.

You can with a glorified text-editor these days with Code Inspection. I guess that's advanced stuff we shouldn't expect our co-workers to use?

> If the function is trivial, which is exactly what we've been talking about this whole time, then No. Fucking. Shit. The function is trivial and they have the source code right there.

Yet, if the function is trivial AND is imported via npm, it suddenly requires reading docs. On one hand you argue "triviality requires reading docs" and then suggest that you can implement a similar trivial function and everyone can just look at the source code.

And you don't see the irony here.

[BigJono]

You're conflating a trivial function with a trivial API. The whole reason I jumped into this thread is because classnames is a great example of a trivial function with a non-trivial API. Yes, you do need to look up either the docs or the implementation to understand how to use it. I think my past examples made that clear.

What I'm saying is that it's EASIER to understand the source code than it is to understand the documentation for classnames. That's because it abstracts nothing away. It's replacing one simple API (template strings) with another one that's very similar and of roughly the same power. By turning it into a dependency you're adding an artificial barrier between it and your code base, that makes it harder for everyone to grok. Not much harder, but enough to be a pain in the ass in any codebase where that same tradeoff is made over and over.

If you can't understand that, then I don't know what to do for you. Keep writing shit JS code and making the web worse than it already is.