v9.0.0-beta.0

This beta release fixes the imports of use-sync-external-store when used in an ESM environment, and includes the fixes in v8.1.3.

npm i react-redux@beta

yarn add react-redux@beta

We currently do not anticipate any major development or changes with React-Redux before v9 goes final, but that will be done in conjunction with the Redux Toolkit 2.0 release when it is ready.

What's Changed

• Add stack to dev mode checks by @EskiMojo14 in #2064
• Fix uSES imports and run against RTK CI examples by @markerikson in #2070
• Fix useSelector() in combination with lazy loaded components breaks with react v18 (#1977) by @jeroenpx in #2068

Full Changelog: v9.0.0-alpha.1...v9.0.0-beta.0

v8.1.3

This bugfix release fixes an issue with subscriptions being lost when lazy-loaded components are used with React Suspense, and includes stack traces in useSelector usage warnings .

What's Changed

• Add stack to dev mode checks by @EskiMojo14 in #2064
• Fix useSelector() in combination with lazy loaded components breaks with react v18 (#1977) by @jeroenpx in #2068

Full Changelog: v8.1.2...v8.1.3

v9.0.0-alpha.1

This alpha release adds an extra entry point that will automatically throw errors when any API is used in a React Server Components environment, inlines the hoist-non-react-statics dep, and updates context types.

Changelog

React Server Components Behavior

Per Mark's post "My Experience Modernizing Packages to ESM", one of the recent pain points has been the rollout of React Server Components and the limits the Next.js + React teams have added to RSCs. We see many users try to import and use React-Redux APIs in React Server Component files, then get confused why things aren't working right.

To address that, we've added a new entry point with a "react-server" condition. Every export in that file will throw an error as soon as it's called, to help catch this mistake earlier.

hoist-non-react-statics Dep Inlined

Higher Order Components have been discouraged in the React ecosystem over the last few years. However, we still include the connect API. It's now in maintenance mode and not in active development.

As described in the React legacy docs on HOCs, one quirk of HOCs is needing to copy over static methods to the wrapper component. The hoist-non-react-statics package has been the standard tool to do that.

We've inlined a copy of hoist-non-react-statics and removed the package dep, with the hope that this will ensure better tree-shaking in some projects.

Context Type Updates

We've made some tweaks to our ReactReduxContextValue type to better reflect actual behavior.

What's Changed

• add an extra entrypoint for React Server Components by @phryneas in #2062
• Inline hoist-non-react-statics to eliminate a dep and help shaking by @markerikson in #2066
• Make context typing more accurate by @EskiMojo14 in #2041

Full Changelog: v9.0.0-alpha.0...v9.0.0-alpha.1

v9.0.0-alpha.0

This is an alpha release for React-Redux 9.0. This release has many changes to our build setup and published package contents, and has breaking changes.

npm i react-redux@alpha

yarn add react-redux@alpha

This is part of the next set of major versions for all of the Redux packages, including:

• Redux Toolkit 2.0-beta
• Redux core 5.0-beta

Please try out this alpha and give us feedback on how it works!

Changelog

React 18 and Redux 5 Are Required

React-Redux 7.x and 8.x worked with all versions of React that had hooks (16.8+, 17.x, 18.x). However, React-Redux v8 used React 18's new useSyncExternalStore hook. In order to maintain backwards compatibility with older React versions, we used the use-sync-external-store "shim" package that provided an official userland implementation of the useSyncExternalStore hook when used with React 16 or 17. This meant that if you were using React 18, there were a few hundred extra bytes of shim code being imported even though it wasn't needed.

For React-Redux v9, we're switching so that React 18 is now required! This both simplifies the maintenance burden on our side (fewer versions of React to test against), and also lets us drop the extra bytes because we can import useSyncExternalStore directly.

React 18 has been out for a year and a half, and other libraries like React Query are also switching to require React 18 in their next major version. This seems like a reasonable time to make that switch.

Similarly, React-Redux now depends on Redux core v5 for updated TS types (but not runtime behavior).

ESM/CJS Package Compatibility

The biggest theme of the Redux v5 and RTK 2.0 releases is trying to get "true" ESM package publishing compatibility in place, while still supporting CJS in the published package. We've now applied those same packaging changes to React-Redux.

We've set up a battery of example applications in the RTK repo that use a variety of build tools (currently CRA4, CRA5, Next 13, and Vite, Node CJS mode, and Node ESM mode), to verify that Redux and Redux Toolkit compile, import, and run correctly with both TS and various bundlers. We're also using the CLI from https://arethetypeswrong.github.io to check for potential packaging incompatibilities.

This release changes the names and contents of the published build artifacts, and the various exports/module/main fields in package.json to point to those.

The primary build artifact is now an ESM file, dist/react-redux.mjs. Most build tools should pick this up. There's also a CJS artifact, and a second copy of the ESM file named react-redux.legacy-esm.js to support Webpack 4 (which does not recognize the exports field in package.json).

As of this release, we think we have ESM+CJS compat working correctly, but we ask that the community try out the alphas in your apps and let us know of any compat problems!

Note: The one known potential issue is that TypeScript's new moduleResolution: "node16" mode may see a mismatch between the ESM artifacts and the TS typedefs when imported in a Node CJS environment, and that may allow hypothetically-incorrect import usage. (See ongoing discussion in arethetypeswrong/arethetypeswrong.github.io#21 .) In practice, we think that probably won't be a concern, and we'll do further investigation before a final release.

Build Tooling

We're now building the package using https://github.com/egoist/tsup . It looks like the output is effectively equivalent, but please let us know if there's any issues.

We also now include sourcemaps for the ESM and CJS artifacts.

Dropping UMD Builds

The Redux packages have always shipped with UMD build artifacts. These are primarily meant for direct import as script tags, such as in a CodePen or a no-bundler build environment.

For now, we're dropping those build artifacts from the published package, on the grounds that the use cases seem pretty rare today.

We do have a browser-ready ESM build artifact included at dist/react-redux.browser.mjs, which can be loaded via a script tag that points to that file on Unpkg.

If you have strong use cases for us continuing to include UMD build artifacts, please let us know!

React Server Component Compatibility

For this initial alpha, we've marked the React-Redux bundles with the "use client" label. This at least seems to let an example Next.js app build even if it imports useSelector into an RSC page file, but to be honest we're still figuring this stuff out! Expect further changes before a final release.

TypeScript Updates

React-Redux now depends on the updated TS types from Redux core v5. This mostly involves uses of UnknownAction everywhere instead of AnyAction.

What's Changed

• Update packaging, build config, and entry points for v9 by @markerikson in #2038

Full Changelog: v8.1.2...v9.0.0-alpha.0

v8.1.2

This version changes imports from the React package to namespace imports so the package can safely be imported in React Server Components as long as you don't actually use it - this is for example important if you want to use the React-specifc createApi function from Redux Toolkit.

Some other changes:

• The behaviour of the "React Context Singletons" from 8.1.1 has been adjusted to also work if you have multiple React instances of the same version (those will now be separated) and if you are in an environment without globalThis (in this case it will fall back to the previous behaviour).
• We do no longer use Proxies, which should help with some very outdated consumers, e.g. smart TVs, that cannot even polyfill Proxies.

Full Changelog: v8.1.1...v8.1.2

v8.1.1

This bugfix release tweaks the recent lazy context setup logic to ensure a single React context instance per React version, and removes the recently added RTK peerdep to fix an issue with Yarn workspaces.

Changelog

React Context Singletons

React Context has always relied on reference identity. If you have two different copies of React or a library in a page, that can cause multiple versions of a context instance to be created, leading to problems like the infamous "Could not find react-redux context" error.

In v8.1.0, we reworked the internals to lazily create our single ReactReduxContext instance to avoid issues in a React Server Components environment.

This release further tweaks that to stash a single context instance per React version found in the page, thus hopefully avoiding the "multiple copies of the same context" error in the future.

What's Changed

• fix: fix typescript error on non exported type by @luzzif in #2034
• create singleton context by React version by @phryneas in #2039
• remove RTK peerDep by @markerikson in 44fc725

Full Changelog: v8.1.0...v8.1.1

v8.1.0

This feature release adds new development-mode safety checks for common errors (like poorly-written selectors), adds a workaround to fix crash errors when React-Redux hooks are imported into React Server Component files, and updates our hooks API docs page with improved explanations and updated links.

Changelog

Development Mode Checks for useSelector

We've had a number of users tell us over time that it's common to accidentally write selectors that have bad behavior and cause performance issues. The most common causes of this are either selectors that unconditionally return a new reference (such as state => state.todos.map() without any memoization ), or selectors that actually return the entire root state ( state => state ).

We've updated useSelector to add safety checks in development mode that warn if these incorrect behaviors are detected:

• Selectors will be called twice with the same inputs, and useSelector will warn if the results are different references
• useSelector will warn if the selector result is actually the entire root state

By default, these checks only run once the first time useSelector is called. This should provide a good balance between detecting possible issues, and keeping development mode execution performant without adding many unnecessary extra selector calls.

If you want, you can configure this behavior globally by passing the enum flags directly to <Provider>, or on a per-useSelector basis by passing an options object as the second argument:

// Example: globally configure the root state "noop" check to run every time
<Provider store={store} noopCheck="always">
  {children}
</Provider>

// Example: configure `useSelector` to specifically run the reference checks differently:
function Component() {
  // Disable check entirely for this selector
  const count = useSelector(selectCount, { stabilityCheck: 'never' })
  // run once (default)
  const user = useSelector(selectUser, { stabilityCheck: 'once' })
  // ...
}

This goes along with the similar safety checks we've added to Reselect v5 alpha as well.

Context Changes

We're still trying to work out how to properly use Redux and React Server Components together. One possibility is using RTK Query's createApi to define data fetching endpoints, and using the generated thunks to fetch data in RSCs, but it's still an open question.

However, users have reported that merely importing any React-Redux API in an RSC file causes a crash, because React.createContext is not defined in RSC files. RTKQ's React-specific createApi entry point imports React-Redux, so it's been unusable in RSCs.

This release adds a workaround to fix that issue, by using a proxy wrapper around our singleton ReactReduxContext instance and lazily creating that instance on demand. In testing, this appears to both continue to work in all unit tests, and fixes the import error in an RSC environment. We'd appreciate further feedback in case this change does cause any issues for anyone!

We've also tweaked the internals of the hooks to do checks for correct <Provider> usage when using a custom context, same as the default context checks.

Docs Updates

We've cleaned up some of the Hooks API reference page, and updated links to the React docs.

What's Changed

• check for Provider even when using custom context by @EskiMojo14 in #1990
• Add a stability check, to see if selector returns stable result when called with same parameters. by @EskiMojo14 in #2000
• Add an E2E-ish test that verifies behavior when imported into RSCs by @markerikson in #2030
• lazily create Context for RSC compat by @phryneas in #2025
• Add warning for selectors that return the entire state by @EskiMojo14 in #2022

Full Changelog: v8.0.7...v8.1.0

v8.0.7

This release updates the peer dependencies to accept Redux Toolkit, and accept the ongoing RTK and Redux core betas as valid peer deps.

Note: These changes were initially in 8.0.6, but that had a typo in the peer deps that broke installation. Sorry!

What's Changed

• Bump Redux peer deps to accept 5.0 betas, and bump RTK dev dep by @markerikson in #2017
• d45204f : Fix broken RTK peer dep

Full Changelog: v8.0.5...v8.0.7

v8.0.6

This release updates the peer dependencies to accept Redux Toolkit, and accept the ongoing RTK and Redux core betas as valid peer deps.

This release has a peer deps typo that breaks installation - please use 8.0.7 instead !

What's Changed

• Bump Redux peer deps to accept 5.0 betas, and bump RTK dev dep by @markerikson in #2017

Full Changelog: v8.0.5...v8.0.6

v8.0.5

This release fixes a few minor TS issues.

What's Changed

• Provider: pass state (S) generic through to ProviderProps by @OliverJAsh in #1960
• wrap equalityFn type in NoInfer by @phryneas in #1965
• Fix wrapped component prop types when passing nullish mapDispatchToProps by @marconi1992 in #1928

Full Changelog: v8.0.4...v8.0.5