flow-typed VS reselect

I'm very curious, which "Redux code" are you referring to here?

I don't think the `redux` core lib ever shipped any Flow types itself. Looking at the FlowTyped repo, I see community typedefs at https://github.com/flow-typed/flow-typed/tree/master/definit... , and the Git history suggests those were indeed written by community members.

(of course on the flip side, _I_ didn't even start learning TS myself until 2019, and goodness knows _that_ has been a lot of trial and error over time :) )

As for configurability of whether casts should error, in my experience with flow it's paradoxically riskier to rely on a type nag when refactoring an unknown "offending" type casts. I've ran into cases where upgrading flow raised a cast issue, it got "fixed" it in a way that made the type system happy, but inadvertently broke tests because falsy values are tricky like that. Here's an example where a type nag showed up for someone refactoring, they did what they thought was reasonable to silence it, and proceeded to accidentally break the entire tool (slipping through tests and code review, to boot). This happened in the flow-typed tool of all places.

The process of supporting Flow users is extremely similar to that of TypeScript. Instead of adding the definition file to "types" in package.json, make a .js.flow file alongside every .js file that is being exported (for example, if you export lib/index.js, make sure to create lib/index.js.flow with the definitions). See the docs on how to create such a definition. If you want to support Flow yourself, don't publish to flow-typed; it's mainly meant for community members to create their own types for third-party packages and publish them there.

- Throws better errors in an RSC environment

- https://github.com/reduxjs/react-redux/releases/tag/v9.0.0

## Reselect 5.0:

- Switches to a new `weakMapMemoize` memoizer as default

- Renames `defaultMemoize` to `lruMemoize`

- Allows passing memoizer options direct to `createSelector`

- Many TS improvements

- https://github.com/reduxjs/reselect/releases/tag/v5.0.1

## Redux Thunk 3.0:

- Drops the default export and switches to named exports ( `{thunk, withExtraArgument}` )

- https://github.com/reduxjs/redux-thunk/releases/tag/v3.1.0

This has been a _huge_ year-long development effort!

We're thrilled to get these improvements out. The tooling and bundle improvements will help all users, and we think the features and TS changes will improve the Redux dev experience significantly.

Thank you SO MUCH to everyone who has contributed or helped test out the work!

Please file bug reports for the inevitable issues that pop up post-release!

but now I'm going off on a conf trip and going to take a very well-earned break from Redux work for December :)

reselect -> For making faster queries to store.

Reselect solves this problem by memorizing the values and only passing what’s necessary.

In addition, diagnosing bugs in how data flowed through the application (where data originated from, how it was changed, etc.) was always super painful because I had to backtrack through selectors referencing selectors referencing selectors. And updating high-level selectors risked breaking something else down the line (even with 100% business logic coverage this was a problem). (This may be chalked up to improper usage of reselect, but I'm curious to hear your thoughts. Is this a common problem?)

reselect : Selector library to optimize your store access

Reselect documentation:

Applying memoization to TypeScript and ReactJS is relatively straightforward. There are several libraries available that provide memoization functionality, such as memoize function from Lodash, reselect or hooks from ReactJS. These libraries can be installed using NPM or Yarn and used in your TypeScript and ReactJS projects.

Generally, all you would need is to have your redux store provider at the very top level of your application (You could also only wrap the components that you want to have this data available to). Then, any component rendered inside that provider can get access to the redux store. The suggested approach ever since hooks were released is to use `useSelector` and `useDispatch` within your component to get the state data that you need. Using a selector library like Reselect is prevalent and keeps your data selection tidy & handles memoization for you.

Reselect is a library for creating memoized “selector” functions. Commonly used with Redux, to slice state and provide just the necessary subtree to a React component.