@apollo/client

Apollo Client 3.1.0

Bug Fixes

• Rework interdependencies between @apollo/client/* entry points, so that CommonJS and ESM modules are supported equally well, without any duplication of shared code.
  @benjamn in #6656 and
  #6657

• Tolerate !== callback functions (like onCompleted and onError) in useQuery options, since those functions are almost always freshly evaluated each time useQuery is called.
  @hwillson and @benjamn in #6588

• Respect context.queryDeduplication if provided, and otherwise fall back to client.deduplication (as before).
  @igaloly in #6261 and
  @Kujawadl in #6526

• Refactor ObservableQuery#getCurrentResult to reenable immediate delivery of warm cache results. As part of this refactoring, the ApolloCurrentQueryResult type was eliminated in favor of ApolloQueryResult.
  @benjamn in #6710

• Avoid clobbering defaultOptions with undefined values.
  @benjamn in #6715

Improvements

• breaking

  Apollo Client will no longer modify options.fetchPolicy unless you pass options.nextFetchPolicy to request an explicit change in FetchPolicy after the current request. Although this is technically a breaking change, options.nextFieldPolicy makes it easy to restore the old behavior (by passing cache-first).
  @benjamn in #6712, reverting #6353

• Errors of the form Invariant Violation: 42 thrown in production can now be looked up much more easily, by consulting the auto-generated @apollo/client/invariantErrorCodes.js file specific to your @apollo/client version.
  @benjamn in #6665

• Make the client field of the MutationResult type non-optional, since it is always provided.
  @glasser in #6617

• Allow passing an asynchronous options.renderFunction to getMarkupFromTree.
  @richardscarrott in #6576

• Ergonomic improvements for merge and keyArgs functions in cache field policies.
  @benjamn in #6714