Hide top-level client properties (as they are visible via JS code intellisense)

[schickling]

There a plenty of private fields in the PrismaClient class which are properly hidden when using TypeScript but are visible when a user is working with plain JS. I suggest we move all top-level properties/functions that are not intended for the user to a _ prefixed wrapper property.

[Jolg42]

I believe it's related to this bug in TypeScript Intellisense microsoft/TypeScript#34934

[Jolg42]

Right now it looks like the TypeScript team is aware of it, will work on it and will ship it for 3.9.0 April release.

There is also the "real" # private that should fix this coming to TypeScript in February release 3.8.0 microsoft/TypeScript#30829

[divyenduz]

Internal note: dropping from this sprint

[Jolg42]

It looks like we'll be able to do it with # private feature in TypeScript 3.8 @timsuchanek 🎊

See details from https://devblogs.microsoft.com/typescript/announcing-typescript-3-8-rc/

As we mentioned, another benefit is that subclassing can be easier with ECMAScript’s # privates because they really are private. When using ECMAScript # private fields, no subclass ever has to worry about collisions in field naming. When it comes to TypeScript’s private property declarations, users still have to be careful not to trample over properties declared in superclasses.

Finally, something to consider is where you intend for your code to run. TypeScript currently can’t support this feature unless targeting ECMAScript 2015 (ES6) targets or higher. This is because our downleveled implementation uses WeakMaps to enforce privacy, and WeakMaps can’t be polyfilled in a way that doesn’t cause memory leaks.