typescript - 如何在不为其创建变量的情况下指定一个值必须具有特定类型？

Question

说我有

type TypeMsAnimationDuration =
  | 75
  | 100
  | 150
  | 200
  | 250
  | 300
  | 350
  | 500;

const cssInJs = css`transition: all ${999}ms;`

如何确保值“999”是 TypeMsAnimationDuration 的值？

Answer 1

如果不将其放入变量或创建必须调用以验证值的辅助函数，则无法执行此操作：

type TypeMsAnimationDuration =
| 75
| 100
| 150
| 200
| 250
| 300
| 350
| 500;

function animDuration(ms: TypeMsAnimationDuration) {
    return ms;
}
const cssInJs = css`transition: all ${animDuration(999)}ms;` // Error
const cssInJs = css`transition: all ${animDuration(250)}ms;` // Ok