and | /factories.ts | abstruct@1.0.0-beta.7

function and

import { and } from "https://deno.land/x/abstruct@1.0.0-beta.7/factories.ts";

and<In, A extends In, In2, A2 extends In2>(v1: Validator<In, A>, v2: Validator<In2 | A, A2>): AndValidator<In, A & A2>

Factory for validator composer like Logical AND. and composes multiple validators and creates a new validator. The composed validator executes the validator from left to right, just like the Logical AND operator. If the validation fails en route, the evaluation stops there.

and<In, A extends In, In2, A2 extends In2, In3, A3 extends In3>(

v1: Validator<In, A>,

v2: Validator<In2 | A, A2>,

v3: Validator<In3 | A & A2, A3>,

): AndValidator<In, A & A2 & A3>

and<In, A extends In, In2, A2 extends In2, In3, A3 extends In3, In4, A4 extends In4>(

v1: Validator<In, A>,

v2: Validator<In2 | A, A2>,

v3: Validator<In3 | A & A2, A3>,

v4: Validator<In4 | A & A2 & A3, A4>,

): AndValidator<In,

& A

& A2

& A3

& A4

and<In, A extends In, In2, A2 extends In2, In3, A3 extends In3, In4, A4 extends In4, In5, A5 extends In5>(

v1: Validator<In, A>,

v2: Validator<In2 | A, A2>,

v3: Validator<In3 | A & A2, A3>,

v4: Validator<In4 | A & A2 & A3, A4>,

v5: Validator<In5 |

& A

& A2

& A3

& A4

, A5>,

): AndValidator<In,

& A

& A2

& A3

& A4

& A5

Examples

Example 1

import {
 and,
 between,
 gte,
 int,
 lte,
} from "https://deno.land/x/abstruct@$VERSION/factories.ts";
const _int8 = and(int, lte(128), gte(-127));
const __int8 = and(int, between(-127, 128));

Type-narrowing

Composition of and is type-safe.

Each validator is corrected to satisfy the narrowed type from the previous validators.

Example 2

import {
  and,
  type Validator,
} from "https://deno.land/x/abstruct@$VERSION/mod.ts";
import { assertType, type Has } from "https://deno.land/std/testing/types.ts";
declare const v1: Validator<unknown, string>;
declare const v2: Validator<string, "a" | "b">;
declare const v3: Validator<"a" | "b" | "c", "a">;
const validator = and(v1, v2, v3);

assertType<Has<typeof validator, Validator<unknown, "a">>>(true);

Limit the number of arguments

The number of arguments is limited by overloading to achieve this. Currently it accepts up to 5 arguments. This limit is based on the strict Function.bind type signature. If more than that is needed, you must nest and.