React components should be pure, not "idempotent"

Summary

A blogpost in the React docs confuses idempotence with purity. Even though this might seem a small typo, it is one of essential importance in that blogpost.

Page

https://react.dev/blog/2024/02/15/react-labs-what-we-have-been-working-on-february-2024

Details

Idempotence is a property of a function that it returns the same result if you apply the function twice to itself, for example, the absolute value function abs is idempotent, since, abs(abs(x)) = x. In general terms f : X --> X is idempotent iff f ∘ f = f.

This is confused with a pure function. This is a function that, given the same input, returns the same output. It is side-effect free or written in a "functional" style.

Even if this might seem like a minor mistake; it is one of the essential properties that the compiler should check for and to that extent, especially newer developers should not be confused.

Apri il post del blog di React Labs di febbraio 2024 collegato nell’issue e individua la frase che descrive i componenti React come idempotent. Esamina la spiegazione circostante della purezza, aggiorna la terminologia in modo che la pagina descriva accuratamente la proprietà prevista e verifica la documentazione renderizzata.