I just published a blog post that I've been working on for a while:
The Church Encoding of Simple Algebraic Data Types

Church encodings are cool in that they're a really fundamental theoretical construct in the lambda calculus, a practical tool for making TypeScript code more succinct, and the basis for object algebras, a powerful technique for writing extensible code in object-oriented languages. This post just scratches the surface, but I hope that it will be accessible to TypeScript developers who have some familiarity with functional programming techniques.