Literally what it says: https://github.com/left-pad/left-pad/blob/master/index.js

Now if you ask "but why?", ultra-small packages like this are popular in JS because of the lack of a standard lib. Lots of devs prefer to install a dependency for each one-liner utility rather than write them themselves.

The only added value of those packages is that they're usually unit-tested against weird edge-cases that you might miss if you wrote them yourself.

Edit: related discussion at https://news.ycombinator.com/item?id=20223190

the small libraries are best compared to stackoverflow code snippets. Instead of reading and copying a solution that may be out of date, you can use a (theoretically) tested solution that receives bug fixes. In many ways it is superior to the copy and paste of lore

You're misunderstanding, what is the use-case of that specific package? like I've never found myself needing to pad text on the left, just trying to understand why this was such an important package.

Probably for command line tools that need to add some level of hierarchy into their output. You can add 1 to pad length and pass it to a subcomponent to display its output.

I don't have any use for it either, but this package is not important by itself. It happens that this package is (was) at the very bottom of the dependency chain for some huge packages (like Babel, Webpack, popular frameworks, ...).

When its creator removed it, they literally destroyed the foundation of those popular packages. That's what made it suddenly important.

The smaller the library, the better.

The less there are dependencies, the better.

> I'm not into js at all

Programming in JS is just this way.

I had to include moment.js yesterday just to format a date. Nothing fancy, but no easy way around it.

I'm not sure this is a good example; dates are actually pretty complicated.

Yes, dates are very complicated. But that doesn't stop pretty much every modern language from having good built-in support for doing this, because it's such a totally common task. JavaScript is such a mess. It doesn't even support integers, for crying out loud, let alone decent date/time/timezone handling. That moment.js is the most popular band-aid to fix this, despite it having a nasty gotcha API that mixes mutable and immutable functions/types in confusing ways just rubs salt into the wound. Heck, you can't even compare two moment dates with inequality operators without either casting them by prepending a plus sign, or calling functions - it just silently does the wrong thing.

Silently? Since when is comparing objects in JS with (in)equality operators the right thing to do? There's no operator overloading nor special symbol you can implement in objects to make this work seamlessly ever. Casting/stringifying or calling functions is the only way for all objects.

You did not have to, moment.js is just a wrapper around the dozens of inbuilt functions provided by the Date object.

Why could you not have used Date.toLocaleDateString() or Date.toDateString() or Date.toISOSting() or any other of the inbuilt functions outlined here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Refe...

The module system in Node.js (not ES6 modules) makes it super easy to use modules because a module is bound to a variable and you can require the module from anywhere and it will be scoped to the function. It's like if all code in the global JavaScript collective is available in global scope.

Its easier to use a community module in Node.js then it is to use a standard library feature in most programming languages.

JS didn't have a pad method in its standard library, so you needed left pad to do that. Now you have padStart, so it's not really necessary.