Questions about type-safety

[jakob-lilliemarck]

Really a question more than an actual issue. I've been scanning through the docs but from what I've seen the information on this matter is quite thin. I apologize if this is the wrong place for questions, in which case, I ask you to please point me in the direction of where you wish me to re-post it 🙏

This library presents itself as beeing "type-safe":

It may replace the uber/dig fantastic package in simple Go projects. samber/do uses Go 1.18+ generics and therefore offers a typesafe API.
I am struggling a bit to understand what is meant by that in this context really, and how type-safety is enforced. It seems to me that types are enforced at runtime, which really doesn't provide much "safety" - but perhaps I'm doing something wrong?

I pulled down the repository and took the examples/simple/example.go for a spin. I tried to comment all of the methods that provide Wheel, and was hoping to get a static type-error in my editor or a compile error as nothing of type Wheel is provided, but it turns out that the code compiles and that "Simple example" is indeed printed to the terminal upon invoking it 🤔

package main

import (
// preceeding code unmodified...

func main() {
	fmt.Printf("Simple example\n")
	injector := do.New()

	// provide wheels
	// do.ProvideNamedValue(injector, "wheel-1", &Wheel{}) 
	// do.ProvideNamedValue(injector, "wheel-2", &Wheel{})
	// do.ProvideNamedValue(injector, "wheel-3", &Wheel{})
	// do.ProvideNamedValue(injector, "wheel-4", &Wheel{})

   // ...rest of the code unmodified
}

We're currently using uber-fx for dependency injection, and I am not a big fan of the magic it provides. I am trying to understand if samber/do somehow does away with some of that magic, and how it compares in terms of type-safety.

Grateful for any insight into the above, or any pointers to pieces of documentation on type-safety which I may have missed