v4.2.0

This release marks the original createStore API as @deprecated to encourage users to migrate to Redux Toolkit, and adds a new legacy_createStore API as an alias without the deprecation warning.

Goal

Redux Toolkit (the @reduxjs/toolkit package) is the right way for Redux users to write Redux code today:

https://redux.js.org/introduction/why-rtk-is-redux-today

Unfortunately, many tutorials are still showing legacy "hand-written" Redux patterns, which result in a much worse experience for users. New learners going through a bootcamp or an outdated Udemy course just follow the examples they're being shown, don't know that RTK is the better and recommended approach, and don't even think to look at our docs.

Given that, the goal is to provide them with a visual indicator in their editor, like createStore . When users hover over the createStore import or function call, the doc tooltip recommends using configureStore from RTK instead, and points them to that docs page. We hope that new learners will see the strikethrough, read the tooltip, read the docs page, learn about RTK, and begin using it.

To be extremely clear:

WE ARE NOT GOING TO ACTUALLY REMOVE THE createStore API, AND ALL YOUR EXISTING CODE WILL STILL CONTINUE TO WORK AS-IS!

We are just marking createStore as "deprecated":

"the discouragement of use of some feature or practice, typically because it has been superseded or is no longer considered efficient or safe, without completely removing it or prohibiting its use"

For additional details, see the extensive discussion in #4325 .

Rationale

• RTK provides a vastly improved Redux usage experience, with APIs that simplify standard usage patterns and eliminate common bugs like accidental mutations
• We've had suggestions to merge all of RTK into the redux core package, or fully deprecate the entire redux package and rename it to @reduxjs/core. Unfortunately, those bring up too many complexities:
  • We already had a package rename from redux-starter-kit to @reduxjs/toolkit, and all of our docs and tutorials have pointed to it for the last three years. I don't want to put users through another whiplash package transition for no real benefit
  • Merging or rearranging our packages would effectively require merging all of the Redux repos into a single monorepo. That would require hundreds of hours of effort from us maintainers, including needing to somehow merge all of our docs sites together. We don't have the time to do that.
• I don't want to add runtime warnings that would be really annoying

So, this is the minimum possible approach we can take to reach out to users who otherwise would never know that they are following outdated patterns, while avoiding breaking running user code or having to completely rewrite our package and repo structure.

Results

When a user imports createStore in their editor, they will see a visual strikethrough. Hovering over it will show a doc tooltip that encourages them to use configureStore from RTK, and points to an explanatory docs page:

Again, no broken code, and no runtime warnings.

If users do not want to see that strikethrough, they have three options:

• Follow our suggestion to switch over to Redux Toolkit and configureStore
• Do nothing. It's just a visual strikethrough, and it doesn't affect how your code behaves. Ignore it.
• Switch to using the legacy_createStore API that is now exported, which is the exact same function but with no @deprecation tag. The simplest option is to do an aliased import rename:

What's Changed

• Mark createStore as deprecated, and add legacy_createStore alias by @markerikson in #4336

Full Changelog: v4.1.2...v4.2.0