swaf/src/Middleware.ts

import {RequestHandler} from "express";
import {NextFunction, Request, Response} from "express-serve-static-core";
import Application from "./Application";
import {Type} from "./Utils";

export default abstract class Middleware {
    public constructor(
        protected readonly app: Application,
    ) {
    }


    protected abstract handle(req: Request, res: Response, next: NextFunction): Promise<void>;

    public getRequestHandler(): RequestHandler {
        return async (req, res, next): Promise<void> => {
            try {
                if (req.middlewares.find(m => m.constructor === this.constructor)) {
                    next();
                } else {
                    req.middlewares.push(this);
                    return await this.handle(req, res, next);
                }
            } catch (e) {
                next(e);
            }
        };
    }
}

export interface MiddlewareType<M extends Middleware> extends Type<M> {
    new(app: Application): M;
}