如何修改JS函数中Promise返回的响应结构后再返回？

我有如下JavaScript函数：

import service from "services/catalogs";

export const getPaginatedAdminPublications = async (params: URLSearchParams) => {
  params.delete("sort");
  const searchParams = new URLSearchParams(params.get("search"));
  if (searchParams) {
    const publicationId = searchParams.get("id");
    publicationId && params.append("ids[]", publicationId);
    params.delete("search");
    params.delete("id");
  }
  return service.getPaginatedAdminPublications(params);
};

该函数修改params后，调用一个返回Promise的service方法，该Promise返回的结果结构如下：

{
 data: [...],
 metadata: {
 page: 1,
 total_pages: 10
 }
}

我希望将返回结果修改为如下结构：

{
 data: [...],
 metadata: {
 page: 1,
 total_pages: 10
 },
 pagination: {
 page: 1,
 total_pages: 10
 }
}

我尝试了如下代码但未生效，请问这个实现思路可行吗？

export const getPaginatedAdminPublications = async (params: URLSearchParams) => {
  params.delete("sort");
  const searchParams = new URLSearchParams(params.get("search"));
  if (searchParams) {
    const publicationId = searchParams.get("id");
    publicationId && params.append("ids[]", publicationId);
    params.delete("search");
    params.delete("id");
  }
  return service.getPaginatedAdminPublications(params).then(data => {
    return {
        ...data,
        pagination: {
            total: data.data.metadata.total_results,
        }
    }
  });
};

你的实现思路是可行的，但代码里存在两处错误导致未生效：

• 属性路径错误：原返回结构里，metadata直接挂在返回对象上，并非data.data.metadata，正确路径是data.metadata
• 目标字段不匹配：你需要的pagination结构包含page和total_pages，但代码里只写了total，且字段名与需求不符

修复后的代码如下：

export const getPaginatedAdminPublications = async (params: URLSearchParams) => {
  params.delete("sort");
  const searchParams = new URLSearchParams(params.get("search"));
  // 优化判断：URLSearchParams即使无参数也会返回实例，用toString()判断是否有实际参数更严谨
  if (searchParams.toString()) {
    const publicationId = searchParams.get("id");
    publicationId && params.append("ids[]", publicationId);
    params.delete("search");
    params.delete("id");
  }
  return service.getPaginatedAdminPublications(params).then(result => {
    return {
      ...result,
      pagination: {
        page: result.metadata.page,
        total_pages: result.metadata.total_pages
      }
    };
  });
};

如果习惯用async/await写法，也可以改成更直观的版本：

export const getPaginatedAdminPublications = async (params: URLSearchParams) => {
  params.delete("sort");
  const searchParams = new URLSearchParams(params.get("search"));
  if (searchParams.toString()) {
    const publicationId = searchParams.get("id");
    publicationId && params.append("ids[]", publicationId);
    params.delete("search");
    params.delete("id");
  }
  const result = await service.getPaginatedAdminPublications(params);
  return {
    ...result,
    pagination: {
      page: result.metadata.page,
      total_pages: result.metadata.total_pages
    }
  };
};

内容的提问来源于stack exchange，提问作者mouchin777