Searching for a package on npm is more time-consuming than writing 300 lines of code? Perhaps your app has some very specific constraints, but for a simple library like this, I have a hard time believing you could code something up on the fly faster than it would take to npm install the package in question.
I have absolutely written a diffing algorithm like this faster much than it would take to find an appropriate version on npm.
Every so often I try to reach for an npm library, only to find out that it's suboptimal, doesn't handle my edge cases, or just plain worse than the code I would have written.
The last time I tried to do this, I wanted a hash map with custom equality functions on the keys, since JS doesn't have one built-in by default. I searched for about 2 hours and didn't find a single one that actually worked (several claimed to be, but actually didn't work...)
So I wrote my own in about 100 lines. [0]
Data structures and algorithms tend to be really awful on npm.
In the long term, having to manage all these dependencies, keeping track of incompatibility, testing updates, or worse, the lack of management, is time consuming.
