@apollo/client

The optional subscribeAndCount testing utility exported from @apollo/client/testing/core now takes a single generic TResult type parameter, instead of TData. This type will typically be inferred from the observable argument type, but if you have any explicit calls to subscribeAndCount<TData>(...) in your own codebase, you may need to adjust those calls accordingly.

Calling fetchMore for queries using the cache-and-network or network-only fetch policies will no longer trigger additional network requests when cache results are complete. Instead, those complete cache results will be delivered as if using the cache-first fetch policy.

Reimplement useQuery and useLazyQuery to use the proposed useSyncExternalStore API from React 18.

The internal use of options.fetchBlockingPromise by useQuery and useLazyQuery may slightly delay the delivery of network results, compared to previous versions of Apollo Client. Since network results are already delivered asynchronously, these timing differences should not be disruptive in most cases. Nevertheless, please open an issue if the timing differences are a problem for you (and you have no easy workaround).

[Relevant if you use Apollo Client with React Native] Since Apollo Client v3.5.0, CommonJS bundles provided by @apollo/client use a .cjs file extension rather than .cjs.js, so Node.js won't interpret them as ECMAScript modules. While this change should be an implementation detail, it may cause problems for the Metro bundler used by React Native, whose resolver.sourceExts configuration does not include the cjs extension by default.

Remove npm from dependencies, and avoid referencing graphql-js enum value.

To avoid retaining sensitive information from mutation root field arguments, Apollo Client v3.4 automatically clears any ROOT_MUTATION fields from the cache after each mutation finishes. If you need this information to remain in the cache, you can prevent the removal by passing the keepRootFields: true option to client.mutate. ROOT_MUTATION result data are also passed to the mutation update function, so we recommend obtaining the results that way, rather than using keepRootFields: true, if possible.

Internally, Apollo Client now controls the execution of development-only code using the __DEV__ global variable, rather than process.env.NODE_ENV. While this change should not cause any visible differences in behavior, it will increase your minified+gzip bundle size by more than 3.5kB, unless you configure your minifier to replace __DEV__ with a true or false constant, the same way you already replace process.env.NODE_ENV with a string literal like "development" or "production". For an example of configuring a Create React App project without ejecting, see this pull request for our React Apollo reproduction template.

Internally, Apollo Client now uses namespace syntax (e.g. import * as React from "react") for imports whose types are re-exported (and thus may appear in .d.ts files). This change should remove any need to configure esModuleInterop or allowSyntheticDefaultImports in tsconfig.json, but might require updating bundler configurations that specify named exports of the react and prop-types packages, to include exports like createContext and createElement (example).

Respect no-cache fetch policy (by not reading any data from the cache) for loading: true results triggered by notifyOnNetworkStatusChange: true.