realestate-jp/esm/lib/rent/transitions.js

不動産関連のユーティリティ関数を提供するライブラリ

import { calculateAnnualPayment, calculateRenewalFee, isRenewalYear, } from "./utils.js";
/**
 * 年ごとの家賃支払い推移を取得する
 *
 * @param rent 月額家賃
 * @param years 契約年数（デフォルト: 1年）
 * @param fee 月額維持費（デフォルト: 0）
 * @param renewCycle 契約更新の頻度（年単位、デフォルト: 0）
 * @param renewFee 更新料（月数、デフォルト: 0）
 * @param raiseRate 更新時の家賃値上げ率（% 単位、デフォルト: 0）
 * @returns 年ごとの支払い推移リスト
 *
 * @example 使用例
 * ```ts
 * import { getRentTransitions } from "@japanese/realestate";
 *
 * const transitions = getRentTransitions(85000, 10, 5000, 2, 1, 5);
 * console.table(transitions);
 * ```
 */
export function getRentTransitions(rent, years = 1, fee = 0, renewCycle = 0, renewFee = 0, raiseRate = 0) {
    let totalPayment = 0;
    let currentRent = rent;
    const results = [];
    for (let year = 1; year <= years; year++) {
        const isRenewal = isRenewalYear(year, renewCycle);
        const renewalFeeAmount = calculateRenewalFee(currentRent, renewFee, isRenewal);
        const annualPayment = calculateAnnualPayment(currentRent, fee, renewFee, isRenewal);
        totalPayment += annualPayment;
        results.push({
            year,
            rent: Math.round(currentRent),
            monthlyTotal: Math.round(currentRent + fee),
            isRenewal,
            renewalFee: Math.round(renewalFeeAmount),
            totalPayment: Math.round(totalPayment),
        });
        if (isRenewal && raiseRate > 0) {
            currentRent *= 1 + raiseRate / 100;
        }
    }
    return results;
}