refactor.ts

gistfile1.txt

import { pipe } from "fp-ts/lib/function";
import * as E from "fp-ts/lib/Either";
import * as t from "io-ts";
import { WithinRangeInteger } from "./numbers";

export const NonEmptyUint8Array = new t.Type<Uint8Array, String, Array<number>>(
  "NonEmptyUint8Array",
  (u): u is Uint8Array =>
    t.array(WithinRangeInteger(0, 256)).is(u) && u.length > 0,
  (u, c) =>
    t.array(WithinRangeInteger(0, 256)).is(u) && u.length > 0
      ? t.success(new Uint8Array(u))
      : t.failure(u, c, "NonEmptyUint8Array"),
  JSON.stringify
);
export type NonEmptyUint8Array = t.TypeOf<typeof NonEmptyUint8Array>;

export const NonEmptyBuffer = new t.Type<Buffer, String, Buffer>(
  "NonEmptyBuffer",
  (u): u is Buffer => Buffer.isBuffer(u) && u.length > 0,
  (u, c) =>
    Buffer.isBuffer(u) && u.length > 0
      ? t.success(u)
      : t.failure(u, c, "NonEmptyBuffer"),
  Buffer.toString
);
export type NonEmptyBuffer = t.TypeOf<typeof NonEmptyBuffer>;

/**
 * Decodes a non empty array of Uint8 into a non empty Buffer
 */
export const BinaryFromArray = new t.Type<
  NonEmptyBuffer,
  String,
  Array<number>
>(
  "BinaryFromArray",
  NonEmptyBuffer.is,
  (u, c) =>
    pipe(
      NonEmptyUint8Array.validate(u, c),
      E.map(_ => Buffer.from(_)),
      E.chain(_ =>
        _.length > 0
          ? t.success(_)
          : t.failure(_, c, "Cannot parse to a BinaryFromArray")
      )
    ),
  Buffer.toString
);
export type BinaryFromArray = t.TypeOf<typeof BinaryFromArray>;