[JohnDotAwesome]

The compiler can most definitely type-check that code. It's up to you whether or not you want to ignore certain types errors. Want to ignore monkey-patching related errors? Filter out all lines from tsc that include TS2339.

[ojosilva]

I just wanted to say that I absolutely love the fact that tsc errors have codes, such as "TS2339".

This is a fundamental part of error handling and DX that, unfortunately, is left out 10 out of 10 in tooling, applications and libraries alike, in special opensource projects.