Namespace for testing related types

[jasonkuhrt]

🍩 Feature Request

Is your feature request related to a problem?

There's a few assert libraries out there but no single great one.

Describe the solution you'd like

I'd like to make something that assembles ideas from various places such as:

• https://github.com/SamVerschueren/tsd
• https://github.com/dsherret/conditional-type-checks

Describe alternatives you've considered

Making my own library

Teachability, Documentation, Adoption, Migration Strategy

Was thinking of a Check or Assert namespace that would have a bunch of logic types that are often used for testing.