Table of contents

1. Getting Response Keys
2. Response Object
3. Response Array
4. Usage with io-ts

import * as io from "io-ts";
import { AnyPrintable, SelectionOf, table, RowOf, RowsArray } from "../../src";

const t = table(["a", "b"], "t");
const q = t.selectStar();

Getting Response Keys

type K = SelectionOf<typeof q>; // typeof K = 'a' | 'b'

// @ts-expect-error
const k2: K = "c";

Response Object

type R1 = RowOf<typeof q>; // typeof Ret = {a: string | number | null | undefined, b: string | number | null | undefined, }
const ret1: R1 = { a: 1, b: null };

//@ts-expect-error
ret1.c;

Response Array

type R2 = RowsArray<typeof q>; // typeof Ret = {a: string | number | null | undefined, b: string | number | null | undefined, }[]
const ret2: R2 = [] as any;

//@ts-expect-error
ret2?.[0]?.abc;

Usage with io-ts

const ioTsResponse = <
    T extends AnyPrintable,
    C extends { [key in SelectionOf<T>]: io.Mixed }
>(
    _it: T,
    _codec: C
): Promise<io.TypeOf<io.TypeC<C>>[]> => {
    // Get the query string with it.stringify()
    // and implement the DB comms.
    return Promise.resolve([]);
};

const response = await ioTsResponse(t.selectStar(), {
    a: io.string,
    b: io.number,
});

response[0]?.a.charAt(0);
response[0]?.b.toPrecision(2);

//@ts-expect-error
response[0]?.c;

// @ts-expect-error
ioTsResponse(t.selectStar(), { a: io.string });

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This document used eval-md