Safe localStorage with fp-ts for ssr applications

localStorage.ts

import * as ls from 'fp-ts-local-storage'
import { io } from 'fp-ts/lib/IO'
import { none } from 'fp-ts/lib/Option'
import { fold } from 'fp-ts/lib/boolean'
import { constVoid, flow } from 'fp-ts/lib/function'
import { curry } from 'ramda'

const isBrowser = io.of(typeof localStorage === "undefined");

const foldIo = curry(
  flow(
    fold,
    io.of
  )
);

const foldNone = foldIo(io.of(none));
const foldVoid = foldIo(constVoid);

export const removeItem = (key: string) =>
  flow(
    isBrowser,
    foldVoid(ls.removeItem(key))
  );

export const setItem = (key: string) => (value: string) =>
  flow(
    isBrowser,
    foldVoid(ls.setItem(key, value))
  );

export const getItem = (key: string) =>
  flow(
    isBrowser,
    foldNone(ls.getItem(key))
  );

i'd recommend writing a function something like

const equals = a => b => a == b

instead of importing ramda just for that

you're importing IO but i don't see it used anywhere

instead of doing qualified imports for option and localstorage, there are no overlapping imports and you could instead just import setItem, getItem, fold