Kysely•2y ago

Extract OrderBy TS Keys

Hey I have the following query

const getBaseQuery = ({ offset, pageSize, slug }: GetBaseQuery) =>
  db
    .selectFrom((eb) =>
      eb
        .selectFrom(...)
        .innerJoin(...)
        .where(...)
        .select([
          ...
        ])
        .as(...)
    )
    .select([
      ...
    ])
    .offset(offset)
    .limit(pageSize);

const getBaseQuery = ({ offset, pageSize, slug }: GetBaseQuery) =>
  db
    .selectFrom((eb) =>
      eb
        .selectFrom(...)
        .innerJoin(...)
        .where(...)
        .select([
          ...
        ])
        .as(...)
    )
    .select([
      ...
    ])
    .offset(offset)
    .limit(pageSize);

And I'm trying to create a function that accepts that query and adds and orderBy expression based in some conditions

type BaseQuery = ReturnType<typeof getBaseQuery>;

type AddOrderBy = {
  query: BaseQuery;
  key?: 'what do I put here';
  dir?: "asc" | "desc";
};

const addOrderBy = ({ query, key, dir }: AddOrderBy) => {
  ...
};

type BaseQuery = ReturnType<typeof getBaseQuery>;

type AddOrderBy = {
  query: BaseQuery;
  key?: 'what do I put here';
  dir?: "asc" | "desc";
};

const addOrderBy = ({ query, key, dir }: AddOrderBy) => {
  ...
};

How can I get the accepted key value types so I can put them in my type declaration?

4 Replies

Daniel CruzOP•2y ago

@Igal sorry for the ping 😅 I think this might had lost between other posts I was able to make it work in the following way. I'd like your input if this is a good approach or is there any helper I'm not aware of @Igal

type BaseQuery = ReturnType<typeof getBaseQuery>;

//My approach👇
type Key = Parameters<BaseQuery["orderBy"]>["0"];

type AddOrderBy = {
  query: BaseQuery;
  key?: Key;
  dir?: "asc" | "desc";
};

type BaseQuery = ReturnType<typeof getBaseQuery>;

//My approach👇
type Key = Parameters<BaseQuery["orderBy"]>["0"];

type AddOrderBy = {
  query: BaseQuery;
  key?: Key;
  dir?: "asc" | "desc";
};

Igal•2y ago

Hey 👋 Your approach could break if orderBy has overloads. You should infer DB, TB & O of query. And then StringReference<DB, TB> | keyof O roughly:

type AddOrderBy<DB, TB extends keyof DB, O> = {
  query: SelectQueryBuilder<DB, TB, O>,
  key?: StringReference<DB, tB> | keyof O,
  dir?: 'asc' | 'desc'
}

type AddOrderBy<DB, TB extends keyof DB, O> = {
  query: SelectQueryBuilder<DB, TB, O>,
  key?: StringReference<DB, tB> | keyof O,
  dir?: 'asc' | 'desc'
}

not sure what you're gaining out of this wrapper tho

Daniel CruzOP•2y ago

I dropped the function wrapper 😅 but I still need to get the possible keys, since I want to build a type safe white list to pass to my orderBy

type BaseQuery = ReturnType<typeof getBaseQuery>;

type Key = Parameters<BaseQuery["orderBy"]>["0"];

type WhiteList = Key[];

const WHITELIST_ORDER_BY_KEYS: WhiteList = [
  "name",
  "price_btc",
  "sold",
  "marketplace",
];

type BaseQuery = ReturnType<typeof getBaseQuery>;

type Key = Parameters<BaseQuery["orderBy"]>["0"];

type WhiteList = Key[];

const WHITELIST_ORDER_BY_KEYS: WhiteList = [
  "name",
  "price_btc",
  "sold",
  "marketplace",
];

What do you mean by orderBy having overloads?

Igal•2y ago

kysely uses function overloads, might make Parameters<Fn> behave unexpectedly or break between versions if we change overloads order, or add new overloads.

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Extract OrderBy TS Keys