如何以优雅哈希风格将对象作为键实现GraphQL配置复用

针对你需要复用GraphQL字段与权限配置的需求，这里有几个比WeakMap更简洁直观的实现方式：

方案一：用数组存储映射关系，动态生成所需结构 #

把每个字段对应的权限规则用数组存起来，再通过reduce分别生成Schema需要的fields对象和Shield需要的权限配置，既避免重复代码，又保持可读性：

const { query1 } = require('query1')
const { query2 } = require('query2')
const { query3 } = require('query3')

// 统一声明字段与权限的映射
const fieldPermissions = [
  { field: query1, rule: user },
  { field: query2, rule: user },
  { field: query3, rule: admin },
]

// 生成Schema的fields对象（假设query对象有name属性对应GraphQL字段名）
const queryFields = fieldPermissions.reduce((acc, { field }) => {
  acc[field.name] = field
  return acc
}, {})

// 生成Shield的权限配置
const permissions = shield({
  Query: fieldPermissions.reduce((acc, { field, rule }) => {
    acc[field.name] = rule
    return acc
  }, {})
})

// 构建Schema
const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: "Query",
    fields: queryFields
  })
})

如果你的query变量名就是GraphQL字段名（比如query1对应字段名"query1"），可以简化字段名的获取逻辑：

const queryFields = fieldPermissions.reduce((acc, { field }) => {
  const fieldName = Object.keys({ field })[0] // 自动取变量名作为字段名
  acc[fieldName] = field
  return acc
}, {})

方案二：封装辅助函数统一处理 #

如果需要多次复用这类逻辑，可以封装工具函数，输入映射数组直接返回fields和权限配置结构：

function buildQueryConfig(fieldPermissions) {
  const fields = {}
  const queryPermissions = {}
  
  for (const { field, rule } of fieldPermissions) {
    const fieldName = field.name || Object.keys({ field })[0]
    fields[fieldName] = field
    queryPermissions[fieldName] = rule
  }
  
  return { fields, queryPermissions }
}

// 使用示例
const { fields: queryFields, queryPermissions } = buildQueryConfig([
  { field: query1, rule: user },
  { field: query2, rule: user },
  { field: query3, rule: admin },
])

const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: "Query",
    fields: queryFields
  })
})

const permissions = shield({
  Query: queryPermissions
})

方案三：利用对象解构与动态键名 #

如果字段变量名和GraphQL字段名完全一致，这是最简洁的方案：

const { query1 } = require('query1')
const { query2 } = require('query2')
const { query3 } = require('query3')

// 定义所有Query字段
const queryFields = { query1, query2, query3 }

// 定义权限规则，直接复用字段变量名作为键
const queryPermissions = {
  query1: user,
  query2: user,
  query3: admin
}

// 构建Schema和权限
const schema = new GraphQLSchema({
  query: new GraphQLObjectType({
    name: "Query",
    fields: queryFields
  })
})

const permissions = shield({
  Query: queryPermissions
})

内容的提问来源于stack exchange，提问作者Tom