facile-it / json-api-ts

import {tryCatch} from 'fp-ts/lib/Either';

import {pipe, pipeable} from 'fp-ts/lib/pipeable';

import {fromEither, taskEither, taskify} from 'fp-ts/lib/TaskEither';

import {readFile} from 'fs';

const TE = pipeable(taskEither);

const fromString = (s: string) => tryCatch(

  () => JSON.parse(s) as unknown,

  error => error instanceof Error

    ? error

    : Error('Cannot parse JSON data')

);

const fromFile = (path: string) => pipe(

  taskify(readFile)(path),

  TE.mapLeft(({message}) => Error(message)),

  TE.map(b => b.toString()),

  TE.chain(s => fromEither(fromString(s)))

);

export const Json = {

  fromFile: fromFile,

  fromString: fromString

};