apollographql/apollo-client @apollo/client@4.2.0-alpha.3

on GitHub

Minor Changes

• #13206 08fccab Thanks @jerelmiller! - Extend the defaultOptions type-safety work to client.mutate and useMutation.

  The errorPolicy option now flows through to the result types for mutations in the same way it already does for queries:

  • ApolloClient.MutateResult<TData, TErrorPolicy> maps errorPolicy to the concrete shape of data and error:
    • "none" → { data: TData; error?: never }
    • "all" → { data: TData | undefined; error?: ErrorLike }
    • "ignore" → { data: TData | undefined; error?: never }
  • client.mutate and useMutation pick up the declared defaultOptions.mutate.errorPolicy and the explicit errorPolicy on each call to narrow return types accordingly.
  • useMutation.Result.error is narrowed to undefined when errorPolicy is "ignore", since client.mutate never resolves with an error in that case.

  DeclareDefaultOptions.Mutate already accepted errorPolicy; the new behavior is that once you declare it, hook and method return types reflect it:

  // apollo.d.ts
  import "@apollo/client";
  
  declare module "@apollo/client" {
    namespace ApolloClient {
      namespace DeclareDefaultOptions {
        interface Mutate {
          errorPolicy: "all";
        }
      }
    }
  }

  const result = await client.mutate({ mutation: MUTATION });
  result.data;
  //     ^? TData | undefined
  result.error;
  //     ^? ErrorLike | undefined

  Setting errorPolicy on an individual call overrides the default for that call's return type.