> easily preventable is doing a lot of work here. It isn't. It's the most basic value proposition of TypeScript. > This is assuming the types are already writ

> easily preventable is doing a lot of work here. It isn't. It's the most basic value proposition of TypeScript. > This is assuming the types are already written and never need to be maintained. No, it doesn't. You need to write software so that you get an application that does what you wish it to do. Does this surprise you? This is not something that was invented by TypeScript. When a software developer wants to prevent bugs when adding features, what they do is add preconditions and post-conditions to enforce invariants, and they handle code paths specific to both the happy path and failure modes. What static typing does is ensure these checks can be done at compile time, and that failure modes can be prevented by ensuring data types that do not meet conditions cannot be passed to functions. TypeScript allows developers to check preconditions and post-conditions by defining types and adding type assertions that verifies whether an object is of a certain type, and then assert at compile-time if they meet preconditions and post-conditions. If they specify a type that has specific characteristics, the typescript compiler helps them by automatically checking preconditions and post-conditions, and prevent code paths that are proven to be failure-prone. This is the very basic of software development. This can only be interpreted as "maintenance" or "extra work" by someone who thinks it's ok if the program crashes and malfunctions if preventable failure modes are not prevented. This is not a trait of a programming language. This is a trait of your and the level of quality at which you do your job.