问一个 ts 类型提取问题

[emilll]

interface Article {
  filename: string
  title: string
  date: string
}

const articles: Article[] = [
  {
    filename: 'article1',
    title: 'first article',
    date: '2021-04-13T18:10:40.578Z'
  },
  {
    filename: 'article2',
    title: 'second article',
    date: '2021-04-13T19:32:39.556Z'
  }
]

// 从 articles 的 filename 字段提取类型
// 结果 => type ArticleFilename = 'article1' | 'article2'
type ArticleFilename = ???

[codehz]

https://www.typescriptlang.org/play?#code/MYewdgzgLgBAhgJygS2AGwKYRgXhgbQCgYYBvYkmAM2UzDgFsMAuGAckRXQwEY2AaCiRRRMrNjQTR4SVJgFCYAEzhQW7AEwAGDTwC0WgCx6eAZgAqPABzMeW5oa0A6AKwB2KwC02FAL6CSckpqWgx6JnFOOQwNBWCRMXYIDFAwJRkueQDKFTVxbV0DYzNLAE5mUw0K0tcXADZvP0IAXXhsVOgAbkJCKABPAAcMGABBWW4AMVDw4dwYAAp+oZAqDOiIAEp8MABXBgAjDARm-AAiGjpGDFPm7sIO2DhWMcyMKcumOdOo7h5T7oeMH2z3GmHeYSuXzgECU-yAA

这样应该就好了

[emilll]

@codehz 哇，谢谢大佬

[orzfly]

基于楼上，如果还要限制 articles 本身的格式，我知道一个这样的方法：

https://www.typescriptlang.org/play?#code/GYVwdgxgLglg9mABAQwM4BUA86B8AKASkQG8AoRRAJwFMoRKk8ZEBeHRGItRbdRagB5RqYACapEuJgC5J6ImzmkAvqVIwwwysGQRqiAIKVYEADb6yFYDHNhkAW2qzUUShoDm5RLCjnnrjy9RZGF-NzBPVVIIBBcUYxgzagkWFAxMGmRRBFMAT0MEpIBtAF18Ajwir0sKRGtbBydEAHJkQvMARmaAGi8KHz8W60o4tpNzHr7EYNCWgCYABjmOgFoFgBYVjoBmdA6ADmkOhel1hYA6AFYAdn2ALWavZV6KGqsbEUbZVvbqOcnat4YL4ms1UNQYmJ4uNqADajNQYtlmtNjs9gBOaTbOZY9FXS4ANgeT1IJTSiEhLgIAG41FBcgAHfRGGEAMQ+dkcFFSeHpTLgwGhiXMqAIRTAIHsACNqJQSkUAET1T6OBUlWnRWJQFCyFnC6jshpc1IKsb6joK2mU7VS3W-Q0q-QmtCiS1AA

不知道有没有更好的办法。

[emilll]

@orzfly 这个思路可以啊，用函数做代理提取类型。从结果来看很完美了

[ryougifujino]

学习了，一开始还以为不行。