ramda_help.js

function _getInvalidRule (rules, data, value) {
  const resolveRuleResult = partial(_resolveRuleResult, [rules, data, value])
  const reducer = partial(_reducer, [resolveRuleResult])
  return Object.keys(rules).reduce(reducer, Promise.resolve(null))
}

function _reducer (callback, accumulator, key) {
  return pipeP(
    always(accumulator),
    ifElse(identity, always(accumulator), partial(callback, [accumulator, key]))
  )() // why do I end up having to put parens here to invoke the funciton?
}

function _resolveRuleResult (rules, data, value, accumulator, key) {
  return pipeP(
    always(Promise.resolve()),
    partial(checkRule, [rules[key], data, value]),
    ifElse(identity, always(accumulator), always(key))
  )()  // why do I end up having to put parens here to invoke the funciton?
}

function checkRule (rule, data, value) {
  return rule(value, data)
}