Adding type safety to object IDs in TypeScript

Re:Adding type safety to object IDs in TypeScript by int_19h on Tuesday January 30, 2024 @06:18PM (#39197355)

You shouldn't need to write this kind of thing manually for every such type.

[ Parent | on HN ]

Re:Adding type safety to object IDs in TypeScript by ht85 on Wednesday January 31, 2024 @04:46AM (#39201880)

    function is<T extends string>(value: string, prefix: T): value is `${typeof prefix}_${string}` {
      return value.startsWith(`${prefix}_`)
    }

You can now do `is(id, 'user')`.

If you do that often you probably want to create separate functions, e.g.:

    function isFactory<T extends string>(prefix: T) {
      return (value: string) => is(value, prefix)
    }

    const isUser = isFactory('user')
    const isOrder = isFactory('order')

Not too bad.

[ Parent | on HN ]