In case I forget, I've created a self-contained TypeScript library demo on my Github repo.
It's a simple TypeScript project, and very minimal.The library consists of 2 files: rtl.ts and SysUtils.ts
The main project is HowLibraryWorks.ts and you call it like so:
node -r ts-node/register HowLibraryWorks.ts
Once it runs, you will see the following output:
SysUtils initHello
In 2017, with the release of Delphi 10.2 Tokyo, Embarcadero introduced a specialized implementation of the Observer pattern into the System.Classes unit. While it has been in the wild for 9 years, it remains a "hidden" architecture for many, primarily because it serves as the invisible engine behind LiveBindings. Other than live bindings, you can also use the Observer pattern as a way to update component settings to the Windows registry, an .ini file, or persist it elsewhere.
System.Classes