index.js

const assert = require('power-assert');

const util = require('./util');
const Config = require('./config');
const { CODE, MSG } = require('./constant');

class WechatPay {
    constructor(options = {}) {
        assert(options.appid);
        assert(options.mchId);
        assert(options.secretKey);

        this.appid = options.appid;
        this.mch_id = options.mchId;
        this.secretKey = options.secretKey;
    }

    createAppOrder(appParams) {
        const basicParams = {
            appid: this.appid,
            mch_id: this.mch_id,
            nonce_str: util.rand(),
            trade_type: 'APP',
        };
        const mergeParams = Object.assign({}, basicParams, appParams);
        const sign = util.makeSign(this.secretKey, mergeParams);
        mergeParams.sign = sign;

        return util.makeRequest(Config.UNIFIED_ORDER, mergeParams);
    }
    
    signPrePayOrder(prepayId, nonceStr, timestamp) {
        const params = {
            appid: this.appid,
            partnerid: this.mch_id,
            prepayid: prepayId,
            package: 'Sign=WXPay',
            noncestr: nonceStr,
            timestamp,
        }
        const sign = util.makeSign(this.secretKey, params);

        return { code: CODE.SUCCESS, msg: MSG.SUCCESS, data: { sign } }
    }

    verifyNotifyResponse(params) {
        const { sign } = params;
        delete params.sign;

        const signResult = util.makeSign(this.secretKey, params);
        if (signResult === sign) {
            return { code: CODE.SUCCESS, msg: MSG.SUCCESS };
        } else {
            return { code: CODE.FAIL, msg: MSG.SIGN_ERROR };
        }
    }

    queryorder(appParams) {
        const basicParams = {
            appid: this.appid,
            mch_id: this.mch_id,
            nonce_str: util.rand(),
        }
        const mergeParams = Object.assign({}, basicParams, appParams);
        const sign = util.makeSign(this.secretKey, mergeParams);
        mergeParams.sign = sign;

        return util.makeRequest(Config.QUERY_ORDER, mergeParams);
    }

    // refund(appParams) {
    //     const basicParams = {
    //         appid: this.appid,
    //         mch_id: this.mch_id,
    //         nonce_str: util.rand(),
    //     }
    //     const mergeParams = Object.assign({}, basicParams, appParams);
    //     const sign = util.makeSign(this.secretKey, mergeParams);
    //     mergeParams.sign = sign;

    //     return util.makeRequest(Config.REFUND, mergeParams);
    // }
}

module.exports = WechatPay;