This is kind of a subtle idea, but in some instances, the illusion of safety can be harmful. It is occasionally (not always) better not to give people the illusion of safety when that safety doesn't actually exist. Sometimes putting an ineffective railing along a mountain path increases accidents, because it's human nature for people walking on that path to watch their footing less when they see the railing.
>> Do not use random libraries. A good library should have even some basic docs outline its API and how to use it.
> A whole lot of the time, especially in Javascript land you will join projects where libraries are being used, and where documentation is lacking. Your advice here is basically to not be part of those projects? Instead of developing and using tooling that will ensure that these situations no longer happen?
I'm not here to hate on Typescript, I think it has its uses. I use Typescript in some places. I generally avoid it for personal projects, but I would probably encourage it for larger orgs.
But the idea that Typescript protects you from needing to care about interfaces is exactly the problem with over-reliance on Typescript, and is the source of a lot of really badly written code that treats interface design like an afterthought. If you're using Typescript for documentation and you're treating it like a tool, you can write some really elegant code, you can catch some shallow bugs around types and assumptions, you can integrate your documentation into your IDE. If you're looking at Typescript and saying, "this is an efficient way for me to document what my code does", then this is all very good.
But if you're using Typescript and saying, "now I can pull in any dependency I want", then Typescript is doing you more harm than good.
The specific advice orange gives in those two sentences is good advice. If Typescript is giving you a false sense of confidence about using random libraries, then that's a real negative.
I use both pure JS and Typescript almost daily, and I consume plenty of dependencies written in Typescript. I still occasionally need to debug the stack traces in those dependencies. I still occasionally need to read through their source code to figure out what they're doing. Badly documented dependencies are not a problem that Typescript solves.