why-did-you-render VS eslint-plugin-react

For debugging why a specific component re-renders, there is also why did you render

It's a combination of many things, but imo one of the worst is all the footguns regarding state and the rerenders they cause

https://emnudge.dev/blog/react-hostage

It's so easy, that we monkey patch react to debug it https://github.com/welldone-software/why-did-you-render

Plus the vdom... Isn't great, the bundle size puts react at an inherit disadvantage, and the community has a knack for over reliance on bloated packages

When we implemented the MVP of the fintech app, we had a quite complicated form. At that time, I was still young and inexperienced. And eventually, we realized that our project was slowing down. We had to spend additional hours figuring out the reason. We had many unnecessary re-renders because we ignored basic rules related to props in React. I wanted to do everything possible to avoid such situations in the future. So, I added to the project linters like this and an additional starting configuration to package.json to run why-did-you-render. In short, this plugin issues a warning if something is re-rendered unnecessarily and suggests how to avoid it. Also, we included running Lighthouse in headless mode. Some people say that premature optimizations are bad, but for me, it's a principle: do it right from the start.

Couple of questions popped up after discovering this tool called `why-did-you-render`. My understanding is that it helps you keep track of why certain components render.

Not exactly what you are looking for (stop runaway effects is it) but this helps diagnose re-renders which can be related: https://github.com/welldone-software/why-did-you-render

> [1] https://github.com/jsx-eslint/eslint-plugin-react/blob/maste...

From what I remember, being able to pass children as a prop is considered a side-effect of an implementation detail, that breaks the expected abstraction. There really isn't any reason to use it, and I think there's a chance it may even confuse the virtual dom diffing?

Also this would prevent you from accidentally doing both at once:

  Is it me?}>

This is pretty compelling. Why isn't it in the "recommended" preset of lints?

In general, I find it frustrating that the eslint recommended presets don't document why they are recommended. I disable several of the rules in all my projects because they seem to be arbitrary stylistic choices (e.g. [0], [1], [2]).

[0] https://typescript-eslint.io/rules/no-empty-function/

[1] https://github.com/jsx-eslint/eslint-plugin-react/blob/maste...

[2] Specifically checkLoops of https://eslint.org/docs/latest/rules/no-constant-condition

For what it's worth; `eslint-plugin-react` has been around for a long time and seems to support running in very old versions of Node.JS (back to v4[1] apparently! tho I can't find anything documenting that for sure.)

I was surprised to learn that Object.values is only supported in Node >v7, Object.fronEntries was added in v12, etc. So for this project maybe the polyfills are needed.

[1] https://github.com/jsx-eslint/eslint-plugin-react/pull/1038

I try to focus on the issues rather than individuals, but the root of the problems in the listed eslint plugin libraries points to ljharb.

If you do some simple digging into these libraries, you will find that these types of commits are quite common within them.

https://github.com/jsx-eslint/eslint-plugin-react/commit/e1d...

https://github.com/jsx-eslint/jsx-ast-utils/commit/bad51d062...

https://github.com/jsx-eslint/eslint-plugin-jsx-a11y/commit/...

He would rather see the download count of these polyfill libraries https://github.com/ljharb/ljharb#projects-i-maintain increase, compared to assessing the health of the JavaScript ecosystem.

An obvious pick for React projects, but eslint-plugin-react along with their plugin:react/recommended rule set is a must. This will give you some sensible rules such as requiring a key to be specified in JSX arrays. eslint-config-airbnb is another good (if a bit loose) base rule set on top of eslint-plugin-react to start from.

You can also add ESLint now (props to @femincan for the suggestion). It comes with recommended settings for these plugins: typescript, prettier, react, react-hooks, jsx-a11y.

Thanks for weighing in, that's good to know. After wondering if this could be auto-refactored, I came across https://github.com/jsx-eslint/eslint-plugin-react/blob/maste..., will definitely have to give that (with `--fix`) a try in the new year and see if I can get the team on board! – desire for typescript being a compelling factor.

Personally I do like the non-destructured `props.abc` throughout component code, really helps clarify at a glance where something is coming from, whether it's locally or externally defined, etc. Code style is an endless exercise in compromises/opinions though, even _with_ tools like eslint and prettier.

eslint-plugin-react react/hook-use-state

The conclusion is to pass callback functions to setState hooks when one needs the current state or props to calculate the next state. React is then able to reliably queue up these "pipes" / transformations to apply to the current state, without relying on what the current state actually is. This is almost so important that there should be an ESLint plugin for this (and there is one).

eslint-plugin-react: React specific linting rules for ESLint.