Type safe persist paths

[biesbjerg]

Clear and concise description of the problem

Would be nice to make paths be type safe to prevent errors.

export const usePlayerStore = defineStore("player", () => {
  return {
    keyA: true,
    keyB: true,
    keyC: {
      keyC1: true,
    },
  };
}, {
  persist: {
    paths: ["keyA", "keyb"] // oops, keyB is mis-spelled
  },
});

Suggested solution

You can do this today:

type FlattenKeys<
  T extends Record<string, unknown>,
  Key = keyof T,
> = Key extends string
  ? T[Key] extends Record<string, unknown>
    ? `${Key}.${FlattenKeys<T[Key]>}`
    : `${Key}`
  : never;

type StateKeys = FlattenKeys<ReturnType<typeof storeFn>>;

function storeFn() {
  return {
    keyA: true,
    keyB: true,
    keyC: {
      keyC1: true,
    },
  };
}

export const usePlayerStore = defineStore("player", storeFn, {
  persist: {
    paths: ["keyA", "keyb", "keyC.keyC1"] satisfies StateKeys[], // Will complain that `keyb` does not exist
  },
});

Alternative

It would be great to have this built-in to Pinia so you wouldn't have to separate the storeFn by it self to be able to get the ReturnType.

Additional context

No response

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[prazdevs]

This is planned someday when i get some time, maybe for v4, as i already made a package for it (see https://github.com/prazdevs/deep-pick-omit)

I'm just overworked and can't spend much time onthe project atm.

[biesbjerg]

No worries — thank you for a great plugin! 😊