Question

我正在使用一个名为EnvObj的库来帮助我在用Typescript编写的Node项目中设置环境变量。我的env.ts文件看起来像这样：

import env = require('envobj')

export interface Env {
  "PORT": number,
  "PG_CONNECTION" : string,
  "REDIS_CONNECTION": string,
  "SERVER_HOST": string,
  "SERVER_SECURE": boolean,
  "COOKIE_KEY": string,
  "GOOGLE_API_CLIENT_ID": string,
  "GOOGLE_API_CLIENT_SECRET": string,
  "GOOGLE_API_DOMAIN": string,
  "CLEARBIT_API_KEY": string
}

export default env <Env>({
  "PORT": 3000,
  "PG_CONNECTION": String,
  "REDIS_CONNECTION": String,
  "SERVER_HOST": 'localhost:3000',
  "SERVER_SECURE": false,
  "COOKIE_KEY": String,
  "GOOGLE_API_CLIENT_ID": String,
  "GOOGLE_API_CLIENT_SECRET": String,
  "GOOGLE_API_DOMAIN": '',
  "CLEARBIT_API_KEY": String
})

运行代码时，出现以下错误：

src/support/env.ts:16:20 - error TS2344: Type 'Env' does not satisfy the constraint 'ValidResult'. Index signature is missing in type 'Env'.

如果我深入研究envobj，则ValidResult接口如下所示：

interface ValidResult {
    [key: string]: string | number | boolean
}

似乎与所写的Env接口兼容。

向Env对象添加索引签名会给我这个错误：

src/support/env.ts:17:26 - error TS2345: Argument of type '{ "PORT": number; "PG_CONNECTION": StringConstructor; "REDIS_CONNECTION": StringConstructor; "SER...' is not assignable to parameter of type 'Config<Env>'.
  Property '"PORT"' is incompatible with index signature.
    Type 'number' is not assignable to type 'never'.

 17 export default env <Env>({
                             ~
 18   "PORT": 3000,
    ~~~~~~~~~~~~~~~
...
 27   "CLEARBIT_API_KEY": String
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 28 })
    ~

知道我要去哪里哪里吗？

Answer 1

听起来很奇怪，如果您将Env指定为type而不是interface，错误就会消失。

import env = require('envobj')

export type Env = {
  "PORT": number,
  "PG_CONNECTION" : string,
  "REDIS_CONNECTION": string,
  "SERVER_HOST": string,
  "SERVER_SECURE": boolean,
  "COOKIE_KEY": string,
  "GOOGLE_API_CLIENT_ID": string,
  "GOOGLE_API_CLIENT_SECRET": string,
  "GOOGLE_API_DOMAIN": string,
  "CLEARBIT_API_KEY": string
}

// No more error!
export default env <Env>({
  "PORT": 3000,
  "PG_CONNECTION": String,
  "REDIS_CONNECTION": String,
  "SERVER_HOST": 'localhost:3000',
  "SERVER_SECURE": false,
  "COOKIE_KEY": String,
  "GOOGLE_API_CLIENT_ID": String,
  "GOOGLE_API_CLIENT_SECRET": String,
  "GOOGLE_API_DOMAIN": '',
  "CLEARBIT_API_KEY": String
})

打字稿错误：类型“ Env”不满足约束条件“ ValidResult”

1 个答案: