askirmas / react-classnaming

import type { Subest } from "./ts-swiss.types"

describe("Subest", () => {

  type SubFunc<Base> = <T extends {[K in keyof Base]?: Base[K]}>(arg: Subest<T, Base>) => (keyof T)[]

  function keying<Base>() {

    return (arg => Object.keys(arg)) as SubFunc<Base>

  }

  type FlatOpt = {

    opt1?: "a"|"b"|"c"

    opt2?: string

  }

  type FlatReq = {

    req1: "a"|"b"|"c"

    req2: string

  }

  it("demo", () => {

    const retOpt = keying<FlatOpt>()({opt1: "a"})

    , retReq = keying<FlatReq>()({req1: "a"})

    , checkOpt: Record<string, typeof retOpt> = {

      "exact": ["opt1"],

      "redundant": ["opt1", 

        //@ts-expect-error

        "opt2"

      ]

    }

    , checkReq: Record<string, typeof retReq> = {

      "exact": ["req1"],

      "redundant": ["req1", 

        //@ts-expect-error

        "req2"

      ]

    }

    expect({checkOpt, checkReq}).toBeInstanceOf(Object)

  })

  it("flat", () => {  

    const check1: Record<string, Subest<{opt1: "a"|"b"}, FlatOpt>> = {

      "exact": {opt1: "a"},

      //@ts-expect-error

      "wrong value": {opt1: "X"},

      "redundant property": {opt1: "a",

        //@ts-expect-error

        redundant: "x"

      }

    }

    expect({check1}).toBeInstanceOf(Object)

  })

})