基于上下文的多个ApolloLink

import { ApolloClient, InMemoryCache, HttpLink } from '@apollo/client';
import { setContext } from '@apollo/client/link/context';
import { onError } from '@apollo/client/link/error';

// 创建一个用于添加认证头的 Link
const authLink = setContext((_, { headers }) => {
  // 获取认证令牌
  const token = localStorage.getItem('token');
  // 返回修改后的请求头
  return {
    headers: {
      ...headers,
      authorization: token ? `Bearer ${token}` : "",
    }
  }
});

// 创建一个用于错误处理的 Link
const errorLink = onError(({ graphQLErrors, networkError }) => {
  if (graphQLErrors)
    graphQLErrors.forEach(({ message, locations, path }) =>
      console.log(`[GraphQL error]: Message: ${message}, Location: ${locations}, Path: ${path}`)
    );
  if (networkError) console.log(`[Network error]: ${networkError}`);
});

// 创建 HttpLink
const httpLink = new HttpLink({ uri: 'https://api.example.com/graphql' });

// 创建 Apollo Client 实例
const client = new ApolloClient({
  link: authLink.concat(errorLink).concat(httpLink),
  cache: new InMemoryCache()
});

export default client;