Given a snippet like this:
import {Foo} from 'testing-mod';
const bar = new Foo();
bar.method();
If this was a real project and you didn't install the package testing-mod
using something like yarn add testing-mod
typescript can't know method
type. It will report method
as any.
This is vital to know if typescript Symbols are related to other symbols.
In this case, if the dependencies were installed, we could easily get the method
definition and ask
its parent which will be reported as Foo
.
If dependencies were not installed method
declaration would be any
and you could not get its parent.