I mentioned above that I feel like the noUncheckedIndexAccess flag isn't a proper solution either. If I pass a Record<'foo', string>, then the compiler should a

I mentioned above that I feel like the noUncheckedIndexAccess flag isn't a proper solution either. If I pass a Record<'foo', string>, then the compiler should allow me to get 'foo' out of the object as a string, not a string|undefined. But you're right that arrays have a similar issue. But I feel like the object-like types have more information for the compiler. An Array<T> doesn't have its length as part of the type (but thankfully, TS does have tuple-types, which is neat). A Record does have information about its keys, so we should be able to infer more information about it. I feel like the Record issue is more akin to if TypeScript had an Array<T, N> type, but still let me access the 3 index of an Array<string, 3> and treat it as a string, even though it should be able to figure out that only indexes 0-2 have strings.