effector-forms FP-way validation example

validation-snippet.js

import { createForm } from "effector-forms"
import { __, assoc, pipe, prop } from "ramda"
import { toString } from "some-library"
import { toGas, toSomeAlienStructure } from "some-other-library-or-something"
import { isOk, isJustFine } from "some-validation-library"

/* Shared library code */
const logged = (value) => {
	console.log(value)
	return value
}

const fromInput = assoc("value", __, { valid: true })

const checked = (predicate) => ({ valid, value }) => ({ valid: valid ? predicate(value) : valid, value })

const ifValid = (converter) => ({ valid, value }) => ({ valid, value: valid ? converter(value) : value })

const toOutput = prop("valid")

/* Business logic */
const form = createForm({
	someValue: {
		init: "",
		rules: [
			{
				name: "someValue",
				validator: pipe(
					fromInput,
					ifValid(toString),
					checked(isOk),
					ifValid(toSomeAlienStructure),
					logged,
					checked(isJustFine),
					logged,
					ifValid(toGas),
					checked((value) => value > 2 && value < 10),
					toOutput,
				)
			},
		],
	}
})