Question

我正在这样设置Apollo Client。

const defaultOptions = {
  watchQuery: {
    fetchPolicy: 'cache-and-network',
    errorPolicy: 'ignore',
  },
  query: {
    fetchPolicy: 'cache-and-network',
    errorPolicy: 'all',
  },
  mutate: {
    errorPolicy: 'all',
  },
};
return new ApolloClient({
  link: ApolloLink.from([authLink, errorLink, webSocketOrHttpLink]),
  defaultOptions, // Typescript don't like this.
  queryDeduplication: true,
});

Typescript出现此错误：

Type '{ watchQuery: { fetchPolicy: string; errorPolicy: string; }; query: { fetchPolicy: string; errorPolicy: string; }; mutate: { errorPolicy: string; }; }' is not assignable to type 'DefaultOptions'.ts(2322)
ApolloClient.d.ts(23, 5): The expected type comes from property 'defaultOptions' which is declared here on type 'ApolloClientOptions<NormalizedCacheObject>'

根据文档，this是应该完成的方式。

如何用适当的类型构造defaultOptions？

Answer 1

如果您随后检查库的代码，则似乎是问题

//defination of default options
export interface DefaultOptions {
 watchQuery?: Partial<WatchQueryOptions>;
 query?: Partial<QueryOptions>;
 mutate?: Partial<MutationOptions>;  
}

//defination of QueryOptions
export interface QueryOptions<TVariables = OperationVariables>
  extends QueryBaseOptions<TVariables> {
  /**
   * Specifies the {@link FetchPolicy} to be used for this query
   */
  fetchPolicy?: FetchPolicy;
}

//valid value for FetchPolicy type 
export type FetchPolicy =
  | 'cache-first'
  | 'network-only'
  | 'cache-only'
  | 'no-cache'
  | 'standby';

export type WatchQueryFetchPolicy = FetchPolicy | 'cache-and-network';

因此，对于此处的查询选项，您应该为FetchPolicy传递任何有效值，而'cache-and-network'则为无效值。

在此处查看文档： https://github.com/apollographql/apollo-client/blob/master/packages/apollo-client/src/core/watchQueryOptions.ts

Answer 2

2021 年：

如果您尝试使用 cache-and-network 作为 query.fetchPolicy 的默认值：

早在 2019 年，cache-and-network 就不能故意用于 query 的原因在此处进行了解释： https://github.com/apollographql/apollo-client/issues/3130#issuecomment-478409066
基本上，query() 的行为/逻辑不支持这种策略。因此，他们在打字级别阻止了它。

反应 useQuery() 钩子

如果您使用的是 react，useQuery() 钩子会遵循 watchQuery 而不是 query 的行为。所以配置 watchQuery 就足够了：

import {
  ApolloClient,
  InMemoryCache,
  HttpLink,
  DefaultOptions
} from "@apollo/client";

const defaultOptions: DefaultOptions = {
  watchQuery: {
    fetchPolicy: "cache-and-network",
    errorPolicy: "ignore",
    notifyOnNetworkStatusChange: true
  }
};
export const platformClient = new ApolloClient({
  link: new HttpLink({
    uri: "https://xxxxx",
    credentials: "same-origin"
  }),
  cache: new InMemoryCache(),
  defaultOptions
});

如何正确键入Apollo客户端defaultOptions？

2 个答案: