[deckard1]

The death from a thousand papercuts.

I'm not terribly convinced with memoization though. You're using extra memory, so it's not free optimization. We have Redux memoized selectors everywhere. I can't help but wonder how much of that is actually a memory leak (i.e. it's never used more than once). Granted, components are a bit different.

I always do cringe when I see a lint rule forcing you to use a spread operator in an array reduce(). It's such a stupid self-inflicted way to turn an O(N) into an O(N^2) while adding GC memory pressure. All to serve some misguided dogma of immutability. I feel there is a need for a corollary to the "premature optimization is the root of all evil" rule.

[Zababa]

> I always do cringe when I see a lint rule forcing you to use a spread operator in an array reduce(). It's such a stupid self-inflicted way to turn an O(N) into an O(N^2) while adding GC memory pressure. All to serve some misguided dogma of immutability. I feel there is a need for a corollary to the "premature optimization is the root of all evil" rule.

I think a rule of "don't try to use X as if it was Y" would be reasonable. I love immutability, but the performance cost in JS is really high. Many people are fine with using Typescript to enforce types at compile time and not at runtime. Maybe many people would be fine with enforced immutability at compile time (Elm, Rescript, OCaml, ...) and not runtime?