Here's a really simple example of the use of assertion signatures in TypeScript We are throwing an error if the product type property is different than the one required. If the function returns without an error being raised, then the product type is asserted to be "Car"

Here's a thread with some use cases of the Extract type from TypeScript 🧵👇

Use case: Filtering items The result type of the filterProducts function, without Extract, would be Product[], even though we know that the resulting array won't contain items that don't satisfy the condition We can use type predicates and generic constraints to improve that

Function overloading in @typescript lets you define functions that can be called in multiple ways Here's a thread with Do's and Don'ts of Function overloading 🧵 Reference: typescriptlang.org/docs/hand…

Use optional parameters instead of defining multiple overload signatures for the same return type