在apollo-server-express中将snake_case转换为camelCase字段名

function snakeToCamel(str) {
  return str.replace(/(_\w)/g, function(m) {
    return m[1].toUpperCase();
  });
}

const snakeToCamelMiddleware = (resolver) => {
  return async (parent, args, context, info) => {
    const result = await resolver(parent, args, context, info);

    if (result) {
      Object.keys(result).forEach((key) => {
        const camelCaseKey = snakeToCamel(key);
        result[camelCaseKey] = result[key];
        delete result[key];
      });
    }

    return result;
  };
};

const { ApolloServer } = require('apollo-server-express');
const express = require('express');
const { applyMiddleware } = require('graphql-middleware');

const typeDefs = // 定义GraphQL的类型定义
const resolvers = // 定义GraphQL的解析器

const server = new ApolloServer({
  typeDefs,
  resolvers: applyMiddleware(resolvers, snakeToCamelMiddleware),
});

const app = express();
server.applyMiddleware({ app });

app.listen({ port: 4000 }, () =>
  console.log(`Server running at http://localhost:4000${server.graphqlPath}`)
);