I am currently working on a project that involves both JavaScript and TypeScript. I am trying to find a solution to reduce code duplication when using JavaScript string constants by converting them into TypeScript types.
For example, let's say I have constants for different log types:
// logTypes.js
export const ERROR = 'error'
export const INFO = 'info'
To reuse these constants, I decided to reexport them:
// constants.js
export * as LOG_TYPES from './logTypes.js'
Now, my goal is to define a TypeScript type for these constants:
// types.d.ts
import { LOG_TYPES } from './constants'
export type LogType = ???
I could simply declare the type this way:
// type LogType = "error" | "info", excellent
export type LogType = typeof LOG_TYPES.INFO | typeof LOG_TYPES.ERROR
However, I believe this approach is redundant and can be hard to maintain if new constants are added in the future.
What I actually want is something like this:
// Does not work as desired
// type LogType = any, meh
export type LogType = typeof LOG_TYPES[string]
I understand the distinction between types and values, but I think this specific part of import/export should be statically analyzable, so there must be a solution that I am unaware of.