@tdsoft/express-routing-wrapper/src/ApiEndpoint.js

Package gives you level of abstraction/wrapping of express router(s), endpoints and middlewares, additionally defining subrouters makes tree structure possible and easily discoverable by root router.

const logger = console; // temporary
const _ = require("lodash");
const createError = require("http-errors");

class ApiEndpoint {
    constructor({
                    access, method,
                    reqBody, reqDbModel, reqQuery, reqCookies, reqHeaders, reqPath,
                    resBody, resDbModel, resCookies
                },
                cb = () => logger.warn("Endpoint has no cb provided!")) {
        this.def = {method};
        this.def.access = {...access};
        this.def.req = {
            body: reqBody,
            dbModel: reqDbModel,
            query: reqQuery,
            cookies: reqCookies,
            headers: reqHeaders,
            path: reqPath
        };
        this.def.res = {body: resBody, dbModel: resDbModel, cookies: resCookies};
        this.cb = cb;
    }

    async expressFn(req, res, next) {
        const credentials = await this._checkAccessRights(req, res, next);
        if (credentials.err) return;

        const errorMsgs = [
            ...this.checkBodyParams(req),
            ...this.checkQueryParams(req),
        ];
        // logger.debug(`this.cb: `, this.cb, this.cb());
        if (errorMsgs.length) {
            next(createError.BadRequest(errorMsgs.join("</br>\n")));
        } else {
            try {
                return await this.cb(req, res, next);
            } catch (error) {
                logger.error(`Error caught: `, error);
                return next(error);
            }
        }
    }

    async _checkAccessRights(req, res, next) {
        const {access} = this.def;
        if (access && access.level && access.cb) {
            return await access.cb(req, res, next, access.level);
        }
        return {};
    }

    _checkRequiredParams(reqAcess, paramsObj, paramsDesc = "") {
        const reqBodyFields = _.chain(paramsObj)
            .reduce((reducer, v, field) => [...reducer, (v.required && field)], [])
            .compact().value();
        //.map((v, key) => key);
        const notPassedFields = reqBodyFields.reduce((reducer, field) => (reqAcess[field]) ? reducer :
            [...reducer, `Passed${paramsDesc} parameters don't contain required "${field}" field.`], []);
        return notPassedFields;

    }

    checkBodyParams(req) {
        return this._checkRequiredParams(req.body, this.def.body, " body");
    }

    checkQueryParams(req) {
        return this._checkRequiredParams(req.query, this.def.query, " query");
    }
}

module.exports = ApiEndpoint;