inceptum/dist/swagger/SwaggerRouterMiddleware.js

"use strict";
// tslint:disable:prefer-function-over-method
Object.defineProperty(exports, "__esModule", { value: true });
const NewrelicUtil_1 = require("../newrelic/NewrelicUtil");
const optionParsingRegExp = /^\s*([^\s]*)\s*\((.*)\)/;
const optionParsingRegExp2 = /[a-zA-Z0-9?:@_-]+/g;
const SWAGGER_CONTROLLER_PROPERTY = 'x-inceptum-controller';
const SWAGGER_OPERATION_PROPERTY = 'x-inceptum-operation';
const newrelic = NewrelicUtil_1.NewrelicUtil.getNewrelicIfAvailable();
function assert(predicate, message) {
    if (!predicate) {
        throw new Error(message);
    }
}
const getControllerName = (req) => req.swagger.operation[SWAGGER_CONTROLLER_PROPERTY]
    ? req.swagger.operation[SWAGGER_CONTROLLER_PROPERTY]
    : req.swagger.path[SWAGGER_CONTROLLER_PROPERTY];
const getOperationName = (req) => req.swagger.operation[SWAGGER_OPERATION_PROPERTY]
    ? req.swagger.operation[SWAGGER_OPERATION_PROPERTY]
    : req.method.toLowerCase();
class SwaggerRouterMiddleware {
    constructor(context) {
        this.context = context;
        this.handlerCache = new Map();
    }
    hasController(req) {
        if (!req || !req.swagger) {
            return false;
        }
        if (req.swagger.operation && req.swagger.operation[SWAGGER_CONTROLLER_PROPERTY]) {
            return true;
        }
        if (req.swagger.path && req.swagger.path[SWAGGER_CONTROLLER_PROPERTY]) {
            return true;
        }
        return false;
    }
    async register(expressApp) {
        expressApp.use(async (req, res, next) => {
            if (newrelic && req.swagger && req.swagger.apiPath) {
                // NR adds a `/` at the start of the path for us.
                const basePath = req.swagger.swaggerObject.basePath.substring(1);
                newrelic.setTransactionName(`${basePath}${req.swagger.apiPath}`);
            }
            try {
                if (this.hasController(req)) {
                    const handler = await this.getControllerHandler(req);
                    assert(handler, `Could not find handler for ${getControllerName(req)}#${getOperationName(req)}. Make sure there is a matching class/method registered on the context.`);
                    try {
                        const resp = await handler(req, res);
                        assert(res.headersSent, `${getControllerName(req)}#${getOperationName(req)} was called but didn't handle the request. Make sure you always handle the request by calling an appopriate method on "res"`);
                    }
                    catch (error) {
                        next(error); // Send to express error handler
                    }
                }
                else {
                    next(); // Not handled, continue up the middleware chain
                }
            }
            catch (e) {
                next(e); // Send to express error handler
            }
        });
    }
    /**
     * @private
     * @param controllerName
     * @returns {*}
     */
    getControllerObjectPromise(controllerName) {
        return this.context.getObjectByName(controllerName);
    }
    /**
     * @private
     * @param req
     * @returns Function
     */
    async getControllerHandler(req) {
        const controllerName = getControllerName(req);
        const operationId = getOperationName(req);
        const key = `${controllerName}_${operationId}`;
        if (this.handlerCache.has(key)) {
            return this.handlerCache.get(key);
        }
        const controller = await this.getControllerObjectPromise(controllerName);
        if (controller) {
            const handler = this.createControllerArgHandler(controller, operationId);
            if (handler) {
                this.handlerCache.set(key, handler);
                return handler;
            }
        }
    }
    /**
     * @private
     * @param controller
     * @param operationId
     * @returns {function(*=, *=)|null}
     */
    createControllerArgHandler(controller, operationId) {
        let functionName;
        let params = [];
        if (operationId.indexOf('(') < 0) {
            functionName = operationId.trim();
        }
        else {
            const matches = operationId.match(optionParsingRegExp);
            functionName = matches[1];
            if (matches[2].trim().length > 0) {
                params = matches[2].match(optionParsingRegExp2);
            }
        }
        if (!controller[functionName]) {
            return;
        }
        const paramFunctions = [];
        params.forEach((param) => {
            if (param === 'null') {
                paramFunctions.push(() => null);
            }
            else {
                paramFunctions.push((req) => req.swagger.params[param].value);
            }
        });
        paramFunctions.push((req) => req);
        paramFunctions.push((req, res) => res);
        return (req, res) => {
            controller.req = req;
            controller.res = res;
            const args = paramFunctions.map((f) => f(req, res));
            return controller[functionName](...args);
        };
    }
}
exports.default = SwaggerRouterMiddleware;
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