[aethr]

Systems like litdb typically include (or work alongside) a schema migration tool, which either reads the current structure of the database and writes that back to a TypeScript file, or reads a TypeScript/schema file and generates a migration to update the database to match the schema. I haven't seen one that works perfectly, and it's up to you to keep it up to date, but as I said it shrinks the surface of where "mistypes" can occur.

It's quite similar to working with a web API. You can invent all the types you want, maybe generated from an OpenAPI schema, but if the server sends something different, TypeScript can't help you. That's not what TypeScript is for.

At the end of the day, most non-scalar TypeScript types "aren't real". Objects can be mutated at runtime, libraries can ship incorrect types, TS can be mixed with JS, etc. We try to introduce types as early as possible to catch a wide swath of possible errors, but where it's really important you still need to verify at runtime.