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This bugfix release removes the isMinified internal check to fix a compat issue with Expo. That check has added in early 2016, soon after Redux 3.0 was released, at a time when it was still less common to use bundlers with proper production build settings. Today that check is irrelevant, so we've removed it.

What's Changed

• Remove minified check by @trajano in https://github.com/reduxjs/redux/pull/4454

Full Changelog: https://github.com/reduxjs/redux/compare/v4.2.0...v4.2.1

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 New learners going through a bootcamp or an outdated Udemy course just follow the examples they're being shown, don't know that RTK is the better and recommended approach, and don't even think to look at our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"the discouragement of use of some feature or practice, typically because it has been superseded or is no longer considered efficient or safe, without completely removing it or prohibiting its use"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 https://github.com/reduxjs/redux/issues/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 https://github.com/reduxjs/redux/pull/4336

Full Changelog: https://github.com/reduxjs/redux/compare/v4.1.2...v4.2.0

⚠️ This is an experimental alpha release. Things may break. If they do, let us know! ⚠️

This release contains the TypeScript codebase conversion work we did in 2019, to let users check compatibility and see if this is suitable for publishing.

Changelog

TypeScript Conversion

In 2019, we began a community-powered conversion of the Redux codebase to TypeScript. The original effort was discussed in #3500: Port to TypeScript, and the work was integrated in PR #3536: Convert to TypeScript.

However, the TS-converted code in master has sat around since then, unused and unpublished, due to concerns about possible compatibility issues with the existing ecosystem (as well as general inertia on our part).

Given the recent updates to Reselect and Redux Thunk, where we successfully published new minor builds that contained conversions to TS and significant rewrites/improvements to the TS types, it's worth publishing the current conversion as an alpha to give the community a chance to report any compatibility issues.

In theory, this should be almost identical in both runtime behavior and types to the recently released 4.1.2 build, but it's very likely that some of the changes may cause types issues.

Please try this out and let us know how it works! We're especially interested in any TS types compatibility issues you might see.

You can provide feedback in #4129: Evaluate current Redux TS port status to determine remaining work for a 5.0 release

Changelog

• See PR #3536: Convert to TypeScript and the PRs that were merged into there for the bulk of the work

This release fixes a small specific TS types issue where state types that had a nested unknown field inside would cause compilation failures when used as the preloadedState argument.

What's Changed

• Fix preloaded state type by @phryneas in https://github.com/reduxjs/redux/pull/4078

Full Changelog: https://github.com/reduxjs/redux/compare/v4.1.1...v4.1.2

Just a small fix for Safari users in development mode.

Changes

• Move miniKindOf out of if scope to fix ES5 compatibility issue (#4090 by @embeddedt)

This release shrinks our bundle size via error message extraction, updates several error messages for clarity, and optimizes our list of runtime dependencies.

Overall, version 4.1 shrinks from 2.6K min+gz to 1.6K min+gz thanks to these changes.

Be sure to check out the Redux Toolkit 1.6 alpha containing our new "RTK Query" data fetching APIs! It also includes Redux 4.1 as a dependency.

Changelog

Error Message Extraction and Improvements

We now extract all of our error messages from production builds in order to save on bundle size, using a technique inspired from React's error code extraction. The error messages will still show as normal in development, but in production they will reference a specific numeric error code and provide a link to a Redux docs page that has the full error message.

An example of this is: https://redux.js.org/errors?code=5 , which shows the "can't subscribe while reducers are executing" error.

The error code extraction saves about 800 bytes out of a production build.

Thanks to @andrewmcgivery for doing all the hard work on implementing the error extraction!

We've also updated many of our error messages to provide additional details at runtime about what happened, especially runtime type checks such as "actions must be plain objects". They now provide a more specific type for the unexpected value, such as indicating promise or function:

    expect(() => store.dispatch(() => {})).toThrow(
      /the actual type was: 'function'/
    )

    expect(() => store.dispatch(new Date())).toThrow(
      /the actual type was: 'date'/
    )

Dependency Updates

We've updated the list of runtime dependencies for Redux:

• We inlined the symbol-observable polyfill. This shrinks bundle size by a few bytes,
• We've removed the legacy loose-envify dependency, which was only ever needed by Browserify users. If you still happen to be using Browserify, please review your build settings and see if you need to make any updates.
• We now explicitly depend on @babel/runtime to extract some additional helpers out of our bundle. It's likely that your app already is pulling in those helpers anyway, so that removes some potential duplication.

Typing Tweaks

We've merged fixes for a couple edge cases in the 4.x TS typings related to state types.

Changes

• Remove symbol-observable and loose-envify deps (#4058 - @markerikson)
• Port error extraction setup from master (#4057 - @markerikson)
• Port build dependencies from master into 4.x (#4056 - @markerikson)
• Rewrite Redux core error messages (#4055 - @markerikson)
• feat: mangle error codes to error indexes (#3920 - @andrewmcgivery)
• fix: Declare "EmptyObject" interface to wrap $CombinedState (#4031 - @JacobLey)
• Only apply mapped types to un-branded types (#3805 - @invliD)

This pre-release for 4.1.0 shrinks our bundle size via tooling updates, and updates several error messages for clarity. This is all the changes we plan to have for 4.1, so if feedback looks good, we'll release 4.1.0 shortly.

Changelog Summary

The 4.1.0 release will have a more complete changelog, but summarizing:

• Shrinks our bundle sizes by extracting error messages from production builds and replacing them with error codes (similar to React). Thanks to @andrewmcgivery for implementing this!
• Inlines the symbol-observable polyfill
• Drops the legacy loose-envify dependency
• Externalizes the @babel/runtime helpers
• Fixed a TS typedef to work better with TS 4.3

We've also updated the error messages to clarify what's happening, provide more details when runtime type checks fail, and link to relevant documentation.

Changes

• Merge pull request #4058 from reduxjs/feature/4x-remove-legacy-deps 9a1d065e
• Inline the symbol-observable polyfill 0d7d94d8
• Remove symbol-observable and loose-envify deps b882d9af
• Merge pull request #4057 from reduxjs/feature/4x-error-messages f3680b5b
• Port error message updates from master 46f5c94d
• Port error extraction setup from master 05d55057
• Merge pull request #4056 from reduxjs/feature/4x-update-build-tooling 82ad6363
• fix: Declare "EmptyObject" interface to wrap $CombinedState (#4031) c3cbe2e0
• Only apply mapped types to un-branded types (#3805) e23aa592

https://github.com/reduxjs/redux/compare/v4.0.5...v4.1.0-alpha.0

This release includes a memory leak fix, and a fix for removing reducers with replaceReducer and combineReducers.

There are also some TypeScript changes, which require version 3.5 or higher. This also removes our DeepPartial type, which wasn't intended to be a public API. If you need this type, you can find an equivalent of likely higher quality in the utility-types package.

Speaking of TypeScript, we are done with converting the code to TypeScript on master and are looking to get some TS improvements in before launching 5.0. If you're interested in helping, feel free to submit a PR with anything you'd like to contribute.

Changes

• Clear current listeners on store unsubscribe (#3475 by @dmitrysteblyuk)
• Fix for combineReducers when replaceReducers removes a reducer (#3490 by @anubhavgupta)
• TypeScript: Add strict type inference overload for combineReducers (#3484 by @ChrisAckerman)
• TypeScript: Preloaded state is now selectively partial (instead of deeply partial) (#3485 by @ChrisAckerman)

This is a republish of 4.0.3 with an updated version of Babel to fix #3468

Changes

This is a quick revert of a change to our typings that broke compatibility. Apologies for the problems.

Also, if you are experiencing type errors related to [Symbol.observable], please ensure you have the same version of redux installed for all your dependencies with npm ls redux.

Changes

• Reverts the change to combineReducers' type parameters (#3467 by @timdorr)