I know this sounds unreliable but in practise I like a language that defaults to pragmatic code paths so I don't have to stay up at night imagining a million code paths

This adds a throwing codepath which is quite drastic so I'm glad people don't build this into programs everywhere - I'd be nice to hear what the team imagine as the use case for this

Normally for correctness I'd like to see specs at the boundaries for programs and different test suites for internal behaviours

Any news on ClojureScript gaining the feature?

> Clojure’s idiomatic use of maps has proven valuable, but missing required keys, misspelled keys, and invalid values can lead to failures that do not connect to the actual source of the problem (e.g. NPEs) making diagnosis difficult. At the same time, Clojure lacks a simple inline mechanism for functions to document and check the keys they require and accept. Existing tools either separate those expectations from the function itself or couple data shape and data provision.