Finding the source code of the node.js native modules, and explanation about typed modules

I have a Windonws machine.
I try to find where node takes the source code for the native module.
All I found is the @types file which contain only such of "Typed Only" modules.
for example, the module "assert" exist in the node github in master/lib folder but in my machine all i find is the typedscript assert.d.ts.
This file, assert.d.ts, DOES NOT COINTAIN ANY INPLEMENTATION , it only contained typed function with no implementation.

Where can I find the code that my machine uses?

also, it will be very nice that the "Step Into" option in debug mode in Visual Studio will lead me to the real source code. right now, it just ignore it when it come to step into modules (on require for example).

Also, when i click CTRL+MOUSE_CLICK on the module name, Visual Studio bring to that "Typed Only" file.

Can someone help my to find and access easy to the real code?

I add an example. this is from assert.d.ts (on user/AppData/.../@types/node/)

function fail(message?: string | Error): never;

and that is all! while in the assert.js in

https://github.com/nodejs/node/blob/master/lib/assert.js

we have the implementation of the function.

If someone can explain me what is going on there behind the scenes I would appreciate it!

Thnaks all

if you are using typescript, the IDE will go to the file definition .d.ts. To find the implementation you must go to your node_modules under the package name and you will have everything.