validate.js

const isOfType = type => (value, key) => {
  if (!(typeof value === type)) {
    throw new Error(`"${key}" must be a ${type}`)
  }
}

const isFalse = (value, key) => {
  if (value !== false) {
    throw new Error(`"${key}" must be false`)
  }
}

const either =
  (...validators) =>
  (value, key) => {
    let errors = []
    for (const validator of validators) {
      try {
        validator(value, key)
        return
      } catch (e) {
        errors.push(e)
      }
    }
    throw new Error(
      `"${value}" at ${key} did not pass either validator : ${errors
        .map(e => e.message)
        .join('\n')}`
    )
  }

const validate = (obj, validators) => {
  for (const key of Object.keys(obj)) {
    const validator = validators[key]
    if (validator) {
      try {
        validator(obj[key], key)
      } catch (e) {
        e.message = 'Validation error: ' + e.message
        throw e
      }
    }
  }
}

const deprecated = (fn, msg) => (value, key) => {
  if (value !== undefined) {
    // eslint-disable-next-line no-console
    console.warn(key, 'is deprecated.', msg)
  }
}

module.exports = {
  validate,
  isOfType,
  deprecated,
  either,
  isFalse
}