static calculateInterestRate (amount: number, rate: number, startDate: Moment, endDate: Moment): Promise<number> {
    const url: string = `${claimApiBaseUrl}/interest/calculate`

    const from: string = MomentFormatter.formatDate(startDate)
    const to: string = MomentFormatter.formatDate(endDate)

    return request.get(
      `${url}?from_date=${from}&to_date=${to}&amount=${amount}&rate=${rate}`
    ).then(response => response.amount)
  }

      it('should reject date of birth below 18', () => {
        const almost18YearsAgo = moment().subtract(18, 'years').add(1, 'days')

        const errors = validator.validateSync(dateOfBirth(almost18YearsAgo.year(), almost18YearsAgo.month() + 1, almost18YearsAgo.date()))

        expect(errors.length).to.equal(1)
        expectValidationError(errors, ValidationErrors.DATE_UNDER_18.replace('%s', MomentFormatter.formatLongDate(ageLimit())))
      })

  static calculatePostponedDeadline (issueDate: Moment): Promise<Moment> {
    const url: string = `${claimApiBaseUrl}/deadline`

    const from: string = MomentFormatter.formatDate(issueDate)

    return request.get(
      `${url}/${from}`
    ).then(response => MomentFactory.parse(response))
  }

export function dateInputFilter (value: moment.Moment | string): string {
  try {
    if (!value || !(typeof value === 'string' || value instanceof moment)) {
      throw new Error('Input should be moment or string, cannot be empty')
    }

    const date: moment.Moment = typeof value === 'string' ? moment(value) : value
    if (!date.isValid()) {
      throw new Error('Invalid date')
    }
    return MomentFormatter.formatInputDate(date)
  } catch (err) {
    logger.error(err)
    throw err
  }
}

export function prepareDefendantOffer (claim: Claim, draft: DraftClaimantResponse): Offer {
  const response: FullAdmissionResponse | PartialAdmissionResponse = claim.response as FullAdmissionResponse | PartialAdmissionResponse

  const amount = NumberFormatter.formatMoney(AmountHelper.calculateTotalAmount(claim, draft))
  if (response.paymentIntention.paymentDate) {
    const completionDate: Moment = response.paymentIntention.paymentDate
    const content: string = `${response.defendant.name} will pay ${amount}, no later than ${MomentFormatter.formatLongDate(completionDate)}`
    return new Offer(content, completionDate, response.paymentIntention)
  } else if (response.paymentIntention.repaymentPlan) {
    const paymentPlan: PaymentPlan = PaymentPlanHelper.createPaymentPlanFromClaim(claim, draft)
    const instalmentAmount: string = NumberFormatter.formatMoney(paymentPlan.instalmentAmount)
    const paymentSchedule: string = PaymentScheduleTypeViewFilter.render(response.paymentIntention.repaymentPlan.paymentSchedule).toLowerCase()
    const firstPaymentDate: string = MomentFormatter.formatLongDate(paymentPlan.startDate)
    const completionDate: Moment = paymentPlan.calculateLastPaymentDate()
    const content: string = `${response.defendant.name} will repay ${amount} in instalments of ${instalmentAmount} ${paymentSchedule}. The first instalment will be paid by ${firstPaymentDate}.`
    return new Offer(content, completionDate, response.paymentIntention)
  }
  throw new Error('Invalid paymentIntention')
}

 it('format moment value to date string', () => {
   expect(MomentFormatter.formatDate(moment('2017-01-01'))).to.eq('2017-01-01')
 })