javascript - 按特定键的值在多个数组中查找对象

Question

我需要通过 target 在多个数组中找到一个对象值并返回 source值(value)。
数据如下所示:

{
  "something": [
    {
      "type": "static",
      "source": "data-access-select",
      "target": "data-access-graphql"
    },
    {
      "type": "static",
      "source": "return-me",
      "target": "find-me"
    }
  ],
  "anything": [
    {
      "type": "static",
      "source": "data-access-page-index",
      "target": "data-access-graphql"
    }
  ]
}

所以有多个数组。

const depsBuffer = await readFile(
  resolve('node_modules/.cache/nx/nxdeps.json')
)
const deps = JSON.parse(depsBuffer.toString('utf-8')).dependencies

for (const [key, value] of Object.entries(deps)) {
  const res = value.find(x => x.target === 'find-me').source
  console.log(res); // expected: 'return-me'
}

但是这样我确实得到了 ts 错误 Property 'find' does not exist on type 'unknown'

Answer 1

报错的原因是TypeScript不知道value是一个数组。它看到 value如 unknown .
尝试指定一种类型来描述 JSON 的预期形状

interface Dependencies {
  [key: string]: Array<{
    type: string,
    source: string, 
    target: string
  }>;
}

const depsBuffer = await readFile(
  resolve('node_modules/.cache/nx/nxdeps.json')
);
const deps = JSON.parse(depsBuffer.toString('utf-8')).dependencies as Dependencies;

for (const [key, value] of Object.entries(deps)) {
  const res = value.find(x => x.target === 'find-me').source;
  console.log(res); // expected: 'return-me'
}