如何实现TypeScript中ERPTypes的model与fields类型动态关联？

问题描述 #

我定义了包含多对象类型的ERPTypes：

type ERPTypes = {
  'res.company': {
     account_enabled_tax_country_ids?: unknown
     account_fiscal_country_id?: false | [number, string]
     account_folder?: false | [number, string]
   }
}

需要创建readQuery函数，要求参数payload的model字段只能是ERPTypes的键，同时fields字段的类型要根据传入的model动态匹配ERPTypes中对应对象的键类型，而非硬编码固定类型。当前代码中fields的类型是硬写的，无法适配多个模型：

export type ReadPayloadT = {
  model: keyof ERPTypes
  ids: number[]
  fields?: (keyof ERPTypes['res.company'])[] // <---- 需动态关联model对应的类型
  with_context?: string
  with_company?: number
}
export const readQuery = (
  payload: ReadPayloadT
): Promise<ERPTypes[keyof ERPTypes][]> => {
  return axios
    .post(process.env['E_URL'] + '/api/v2/read', payload, {
      headers: {
        DATABASE: process.env['E_DB']!,
        Authorization: 'Bearer ' + token,
      },
    })
    .then((res) => res.data)
}

readQuery({
  model: 'res.company',
  ids: [3],
  fields: ['account_fiscal_country_id'],
})

解决方案 #

通过泛型类型实现model与fields的动态关联，具体修改如下：

修改后的完整代码 #

type ERPTypes = {
  'res.company': {
     account_enabled_tax_country_ids?: unknown
     account_fiscal_country_id?: false | [number, string]
     account_folder?: false | [number, string]
   }
  // 可扩展更多ERP模型
  'res.partner': {
    name?: string
    email?: string
    phone?: string
  }
}

// 泛型Payload类型，绑定model与对应字段
export type ReadPayloadT<M extends keyof ERPTypes> = {
  model: M
  ids: number[]
  fields?: (keyof ERPTypes[M])[]
  with_context?: string
  with_company?: number
}

// 泛型函数，返回对应模型的数组类型
export const readQuery = <M extends keyof ERPTypes>(
  payload: ReadPayloadT<M>
): Promise<ERPTypes[M][]> => {
  return axios
    .post(process.env['E_URL'] + '/api/v2/read', payload, {
      headers: {
        DATABASE: process.env['E_DB']!,
        Authorization: 'Bearer ' + token,
      },
    })
    .then((res) => res.data)
}

// 使用示例：自动匹配对应模型的字段
readQuery({
  model: 'res.company',
  ids: [3],
  fields: ['account_fiscal_country_id'] // 仅提示res.company的键
})

readQuery({
  model: 'res.partner',
  ids: [5],
  fields: ['name', 'email'] // 仅提示res.partner的键
})

关键说明 #

• 泛型M被约束为keyof ERPTypes，确保model只能传入ERPTypes中存在的模型键
• fields的类型(keyof ERPTypes[M])[]会根据M的具体值动态推导，实现model与fields的强类型关联
• 返回类型Promise<ERPTypes[M][]>让函数返回的数组元素类型与传入的模型严格对应，避免了联合类型带来的类型模糊

内容的提问来源于stack exchange，提问作者Ilijanovic