@apollo/client

Minor Changes

Memory optimizations

• Simplify RetryLink, fix potential memory leak

  Historically, RetryLink would keep a values array of all previous values, in case the operation would get an additional subscriber at a later point in time.

  In practice, this could lead to a memory leak (#11393) and did not serve any further purpose, as the resulting observable would only be subscribed to by Apollo Client itself, and only once - it would be wrapped in a Concast before being exposed to the user, and that Concast would handle subscribers on its own.

• deprecated

  Deprecates canonizeResults.

  Using canonizeResults can result in memory leaks so we generally do not recommend using this option anymore. A future version of Apollo Client will contain a similar feature without the risk of memory leaks.

• Decouple canonicalStringify from ObjectCanon for better time and memory performance.

• Fix a potential memory leak in FragmentRegistry.transform and FragmentRegistry.findFragmentSpreads that would hold on to passed-in DocumentNodes for too long.

• parse function: improve memory management

  • use LRU WeakCache instead of Map to keep a limited number of parsed results

  • cache is initiated lazily, only when needed

  • expose parse.resetCache() method

• documentTransform: use optimism and WeakCache instead of directly storing data on the Trie

• Fixes a potential memory leak in Concast that might have been triggered when Concast was used outside of Apollo Client.

• Add a resetCache method to DocumentTransform and hook InMemoryCache.addTypenameTransform up to InMemoryCache.gc

• print: use WeakCache instead of WeakMap

• QueryManager.transformCache: use WeakCache instead of WeakMap

• Persisted Query Link: Improve memory management

  • use LRU WeakCache instead of WeakMap to keep a limited number of hash results

  • hash cache is initiated lazily, only when needed

  • expose persistedLink.resetHashCache() method

  • reset hash cache if the upstream server reports it doesn't accept persisted queries

• Use WeakMap in React Native with Hermes

• InMemoryCache.gc now also triggers FragmentRegistry.resetCaches (if there is a FragmentRegistry)

• Adds an experimental ApolloClient.getMemoryInternals helper

• Add reset method to print, hook up to InMemoryCache.gc

Suspense-enabled data fetching on user interaction with useLoadableQuery

• Introduces a new useLoadableQuery hook. This hook works similarly to useBackgroundQuery in that it returns a queryRef that can be used to suspend a component via the useReadQuery hook. It provides a more ergonomic way to load the query during a user interaction (for example when wanting to preload some data) that would otherwise be clunky with useBackgroundQuery.

  function App() {
    const [loadQuery, queryRef, { refetch, fetchMore, reset }] =
      useLoadableQuery(query, options);
  
    return (
      <>
        <button onClick={() => loadQuery(variables)}>Load query</button>
        <Suspense fallback={<SuspenseFallback />}>
          {queryRef && <Child queryRef={queryRef} />}
        </Suspense>
      </>
    );
  }
  
  function Child({ queryRef }) {
    const { data } = useReadQuery(queryRef);
  
    // ...
  }

Begin preloading outside of React with createQueryPreloader

• Add the ability to start preloading a query outside React to begin fetching as early as possible. Call createQueryPreloader to create a preloadQuery function which can be called to start fetching a query. This returns a queryRef which is passed to useReadQuery and suspended until the query is done fetching.

  const preloadQuery = createQueryPreloader(client);
  const queryRef = preloadQuery(QUERY, { variables, ...otherOptions });
  
  function App() {
    return {
      <Suspense fallback={<div>Loading</div>}>
        <MyQuery />
      </Suspense>
    }
  }
  
  function MyQuery() {
    const { data } = useReadQuery(queryRef);
  
    // do something with data
  }

Testing utility improvements

• Support re-using of mocks in the MockedProvider

• Ability to dynamically match mocks

  Adds support for a new property MockedResponse.variableMatcher: a predicate function that accepts a variables param. If true, the variables will be passed into the ResultFunction to help dynamically build a response.

New useQueryRefHandlers hook

• Create a new useQueryRefHandlers hook that returns refetch and fetchMore functions for a given queryRef. This is useful to get access to handlers for a queryRef that was created by createQueryPreloader or when the handlers for a queryRef produced by a different component are inaccessible.

  const MyComponent({ queryRef }) {
    const { refetch, fetchMore } = useQueryRefHandlers(queryRef);
  
    // ...
  }

Bail out of optimisticResponse updates with the IGNORE sentinel object

• Allow returning IGNORE sentinel object from optimisticResponse functions to bail-out from the optimistic update.

  Consider this example:

  const UPDATE_COMMENT = gql`
    mutation UpdateComment($commentId: ID!, $commentContent: String!) {
      updateComment(commentId: $commentId, content: $commentContent) {
        id
        __typename
        content
      }
    }
  `;
  
  function CommentPageWithData() {
    const [mutate] = useMutation(UPDATE_COMMENT);
    return (
      <Comment
        updateComment={({ commentId, commentContent }) =>
          mutate({
            variables: { commentId, commentContent },
            optimisticResponse: (vars, { IGNORE }) => {
              if (commentContent === "foo") {
                // conditionally bail out of optimistic updates
                return IGNORE;
              }
              return {
                updateComment: {
                  id: commentId,
                  __typename: "Comment",
                  content: commentContent,
                },
              };
            },
          })
        }
      />
    );
  }

  The IGNORE sentinel can be destructured from the second parameter in the callback function signature passed to optimisticResponse.

Network adapters for multipart subscriptions usage with Relay and urql

• Add multipart subscription network adapters for Relay and urql

Relay

import { createFetchMultipartSubscription } from "@apollo/client/utilities/subscriptions/relay";
import { Environment, Network, RecordSource, Store } from "relay-runtime";

const fetchMultipartSubs = createFetchMultipartSubscription(
  "http://localhost:4000"
);

const network = Network.create(fetchQuery, fetchMultipartSubs);

export const RelayEnvironment = new Environment({
  network,
  store: new Store(new RecordSource()),
});

Urql

import { createFetchMultipartSubscription } from "@apollo/client/utilities/subscriptions/urql";
import { Client, fetchExchange, subscriptionExchange } from "@urql/core";

const url = "http://localhost:4000";

const multipartSubscriptionForwarder = createFetchMultipartSubscription(url);

const client = new Client({
  url,
  exchanges: [
    fetchExchange,
    subscriptionExchange({
      forwardSubscription: multipartSubscriptionForwarder,
    }),
  ],
});

skipPollAttempt callback function

• Adds a new skipPollAttempt callback function that's called whenever a refetch attempt occurs while polling. If the function returns true, the refetch is skipped and not reattempted until the next poll interval. This will solve the frequent use-case of disabling polling when the window is inactive.

  useQuery(QUERY, {
    pollInterval: 1000,
    skipPollAttempt: () => document.hidden, // or !document.hasFocus()
  });
  // or define it globally
  new ApolloClient({
    defaultOptions: {
      watchQuery: {
        skipPollAttempt: () => document.hidden, // or !document.hasFocus()
      },
    },
  });

QueryManager.inFlightLinkObservables now uses a strong Trie as an internal data structure

Warning: requires @apollo/experimental-nextjs-app-support update

If you are using @apollo/experimental-nextjs-app-support, you will need to update that to at least 0.5.2, as it accesses this internal data structure.

More Minor Changes

• Prevent QueryInfo#markResult mutation of result.data and return cache data consistently whether complete or incomplete.

• Remove the need to call retain from useLoadableQuery since useReadQuery will now retain the query. This means that a queryRef that is not consumed by useReadQuery within the given autoDisposeTimeoutMs will now be auto diposed for you.

  Thanks to #11412, disposed query refs will be automatically resubscribed to the query when consumed by useReadQuery after it has been disposed.

• Remove the need to call retain from useBackgroundQuery since useReadQuery will now retain the query. This means that a queryRef that is not consumed by useReadQuery within the given autoDisposeTimeoutMs will now be auto diposed for you.

  Thanks to #11412, disposed query refs will be automatically resubscribed to the query when consumed by useReadQuery after it has been disposed.

• To work around issues in React Server Components, especially with bundling for
  the Next.js "edge" runtime we now use an external package to wrap react imports
  instead of importing React directly.

• Increase the default memory limits for executeSelectionSet and executeSelectionSetArray.

Patch Changes

• Add a defaultContext option and property on ApolloClient, e.g. for keeping track of changing auth tokens or dependency injection.

  This can be used e.g. in authentication scenarios, where a new token might be generated outside of the link chain and should passed into the link chain.

  import { ApolloClient, createHttpLink, InMemoryCache } from "@apollo/client";
  import { setContext } from "@apollo/client/link/context";
  
  const httpLink = createHttpLink({
    uri: "/graphql",
  });
  
  const authLink = setContext((_, { headers, token }) => {
    return {
      headers: {
        ...headers,
        authorization: token ? `Bearer ${token}` : "",
      },
    };
  });
  
  const client = new ApolloClient({
    link: authLink.concat(httpLink),
    cache: new InMemoryCache(),
  });
  
  // somewhere else in your application
  function onNewToken(newToken) {
    // token can now be changed for future requests without need for a global
    // variable, scoped ref or recreating the client
    client.defaultContext.token = newToken;
  }

• deprecated

  Adds a deprecation warning to the HOC and render prop APIs.

  The HOC and render prop APIs have already been deprecated since 2020,
  but we previously didn't have a @deprecated tag in the DocBlocks.

• Ensure defaultContext is also used for mutations and subscriptions

• Release changes from v3.8.10

• ObservableQuery: Prevent reporting results of previous queries if the variables changed since

• Address bundling issue introduced in #11412 where the react/cache internals ended up duplicated in the bundle. This was due to the fact that we had a react/hooks entrypoint that imported these files along with the newly introduced createQueryPreloader function, which lived outside of the react/hooks folder.

• Clarify types of EntityStore.makeCacheKey.