[v8] Port React-Redux to TypeScript

[markerikson]

React-Redux is currently written in plain JS, and our types have been maintained by the community over in DefinitelyTyped at https://github.com/DefinitelyTyped/DefinitelyTyped/tree/master/types/react-redux/ .

Whenever we get around to writing a React-Redux version 8, we intend to port the library to be written in TypeScript directly.

While we don't yet have plans to work on a new version, it's likely that might happen in the next few months because of React 18 and the Concurrent Rendering changes in that release.

It would be helpful if we could start the work of porting React-Redux to TS now, even if it's just a draft on a branch, so that we have that complex work done ahead of time and can then look at any compat changes for React 18 separately without trying to do both at once.

We maintainers probably don't have the time to tackle this ourselves right now, but I'd love to see the community work on that port so we get it ready.

[chuckdries]

I'm down to help! If no one else has done so by the time I get off work today, I'll spin up a branch and at least configure typescript so we can start working.

[markerikson]

Tell you what. In the interest of keeping collaboration centralized, I'm going to go ahead and create an integration branch here in the main repo. That way we can have PRs and code progress in one place.

[markerikson]

Okay, I just created a new https://github.com/reduxjs/react-redux/tree/typescript-port branch . Let's use that as the target for all PRs for this effort. I'll create a draft integration PR for visibility once we have a first couple commits on that branch.

A couple points to consider:

• The goal for now is to exactly match current React-Redux v7.2.x behavior in both logic and TS. In other words, we're not trying to add any new features or change any TS types, for now. I want an exact match of current functionality as a baseline. Then we can use that as a starting point for any future logic or types changes. That does mean porting over all the ridiculously complicated helper types and overloads that are currently in the React-Redux typedefs.
• We might want to consider pulling over the ESBuild-powered build toolchain that we recently set up for Redux Toolkit. It's slightly less critical here because we aren't going to have multiple entry points the way we now have in RTK, but it's something that we know works and is probably less complicated than using TSDX or similar. See the scripts folder in the RTK repo for the current source of the build toolchain.

[vinay-deshmukh]

@markerikson

Is there any plan / structure on how contributors should start converting .js to .ts?
For example, first the hooks folder, then the connect folder.

So that, we don't get two people working on the same set of files at the same time.

Perhaps something like "sub-issues" to this issue to keep track of which files are being worked on.

[markerikson]

What you see here is all the discussion so far :)

I can help provide some direction and coordination a bit, but I don't have time to be seriously active with this effort for now. So, this needs to be a collaborative thing. That includes filing issues or anything else that needs to be done to help track the work.

[markerikson]

Okay, we've got some basic TS build integration in place, and the first couple files (context and Provider) ported over.

I suspect some of the pieces of connect could be done one file at a time, particularly the selector/map* related files.

[OsidAbu-alrub]

Hello, I'd love to help

[tony-go]

Hi Guys 👋

Very nice initiative 🙌

I'd like to start something on connectAdvanced.js and deps asuseIsomorphicLayoutEffect (Subscription seems to have been migrated already ).

Let me know If it's good.

@markerikson If you think I could start on something "better". Let me know ^^

[markerikson]

I just merged #1743 , which converted several of the smaller files to TS.

If we look at the https://github.com/reduxjs/react-redux/tree/typescript-port branch , here's what's left file-wise atm:

• /src:
  • the entry point files
• /src/components
  • connectAdvanced.js
• /src/connect
  • all files (mapStateToProps.js, etc)
• /src/hooks:
  • useSelector.js
• /src/utils
  • the batchedUpdates files

There's also all the test files that will need to be converted over, and I don't know if we have the test setup itself configured to build / run TS files yet. We also will probably need to copy-paste over additional types and typedefs from the current @types/react-redux package.

I think we ought to save the three biggest pieces of the actual source for last: useSelector.js, connect.js, and connectAdvanced.js.

So, I'd suggest folks should claim a couple of the other files in /connect and work on those first.