midnight/dist/lib/middleware.js

Web framework for building modern web applications

"use strict";
/**
 * @typedef {import('http').IncomingMessage} Request
 * @typedef {import('http').ServerResponse} Response
 * @typedef {() => void} Next
 * @typedef {(req: Request, res: Response, next: Next) => void} Middleware
 */
/**
 * @param {{ log: any, stack: Middleware[] }} app
 * @param {Middleware} fn
 */
exports.use = function (app, fn) {
    app.log.debug("Use middleware ".concat(fn.name || "unknown"));
    app.stack.push(fn);
    return app;
};
/**
 * @param {{ stack: Middleware[], log: any }} app
 * @param {{ stack: Middleware[] }} route
 * @param {Request} req
 * @param {Response} res
 * @param {(err?: Error) => void} callback
 */
exports.handle = function (app, route, req, res, callback) {
    var stack = app.stack.slice(0);
    // Include route specific middleware
    if (route) {
        for (var _i = 0, _a = route.stack; _i < _a.length; _i++) {
            var layer = _a[_i];
            stack.push(layer);
        }
    }
    var index = 0;
    /**
     * @param {Error} [err]
     */
    var next = function (err) {
        // Next layer
        var layer = stack[index++];
        // Stack done
        if (!layer || res.headerSent) {
            if (callback) {
                return callback(err);
            }
            return;
        }
        try {
            app.log.trace("Process middleware ".concat(layer.name || "unknown"));
            if (err) {
                if (layer.length === 4) {
                    layer(err, req, res, next);
                }
                else {
                    next(err);
                }
            }
            else if (layer.length < 4) {
                layer(req, res, next);
            }
            else {
                next();
            }
        }
        catch (e) {
            next(e);
        }
    };
    next();
};