如何在typescript中定义const数组

我的代码:

const WEEKDAYS_SHORT: string[] = ['Dim', 'Lun', 'Mar', 'Mer', 'Jeu', 'Ven', 'Sam']

错误消息来自TypeScript(3.0)编译器:

TS2322:类型'string []'不能赋值为'[string,string,string,string,string,string,string]'.'string []'类型中缺少属性'0'.

如果我更改string[]为ReadonlyArray,则错误消息变为:

TS2322:类型'ReadonlyArray'不能赋值为'[string,string,string,string,string,string,string]'.'ReadonlyArray'类型中缺少属性'0'.

我的tsconfig.json:

{
  "compilerOptions": {
    "declaration": false,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "lib": ["es6", "dom"],
    "module": "es6",
    "moduleResolution": "node",
    "sourceMap": true,
    "target": "es5",
    "jsx": "react",
    "strict": true
  },
  "exclude": [
    "**/*.spec.ts",
    "node_modules",
    "vendor",
    "public"
  ],
  "compileOnSave": false
}

如何在TypeScript中定义只读数组？