typedefinition for nested queries

[TobiasNickel]

Hi, I am about to use sift with my npm module TRDB. tldr: it is a json-file db.
I wanted to add support for mongo-queries and use sift for that.

And I found some issue with the typescript definitions when using a nested query:
in the picture is the you see that address.street has the wrong type definition, the picture also show, that the execution is actually working correct and I find the element with address.streed=mainStreet.

the typescript error is Type '{ $in: string }' is not assignable to type 'string' ts(2322)

my version is 16.0.0,
the typescript version is 4.0.3

Do you know how to get the nested type definitions right?
wand to play with the code: here is the gist.

[crcn]

Heyy, sorry for not getting back to this sooner. The syntax that you'll want to use is this:

const filter = sift({

   // path syntax like this 👇 
  "address.street": { $in: ["mainstreet"] }  
});

const results = [
  {
    address: {
      street: "mainstreet",
    }
  },
  {
    address: {
      street: "not mainstreet",
    }
  }
].filter(filter);

Here's a playground you can play around with: https://mongoplayground.net/p/5YoyNZLBnbf

Unfortunately Sift types don't work with nested fields right now. It looks like this can work, but will require some effort. Here's what I'm looking at: https://stackoverflow.com/questions/58434389/typescript-deep-keyof-of-a-nested-object/58436959#58436959

[mr-rpl]

this addition would be super helpful!

[mr-rpl]

this is not well tested, but on paper works fairly well:

import type { NestedQuery, Query } from 'sift'

type Leaves<T> = T extends Date | Function | RegExp // Exclude special types
  ? never
  : T extends object // Continue processing for objects
    ? {
        [K in keyof T]: `${Exclude<K, symbol>}${Leaves<T[K]> extends never ? '' : `.${Leaves<T[K]>}`}`
      }[keyof T]
    : never

interface Item {
  foo: string
  bar: string
  foobar: {
    foo: string
    bar: string
  }
}

type QueryRecord = Record<Leaves<Item>, NestedQuery<unknown>>

const query: Query<QueryRecord> = {
  foo: {
    $exists: true,
  },
  bar: () => true,
  'foobar.foo': {
    $exists: true,
  },
  'foobar.bar': () => true,
}