Merge pull request #11 from eXigentCoder/master

Test + code to copy properties from the old function to wrapped function

Author: davidbanham

index.js

@@ -1,7 +1,14 @@
 const Layer = require('express/lib/router/layer');
 
+function copyOldProps(oldFn, newFn) {
+  Object.keys(oldFn).forEach((key) => {
+    newFn[key] = oldFn[key];
+  });
+  return newFn;
+}
+
 function wrapErrorMiddleware(fn) {
-  return (err, req, res, next) => {
+  const newFn = (err, req, res, next) => {
     const ret = fn.call(this, err, req, res, next);
 
     if (ret && ret.catch) {
@@ -10,10 +17,11 @@ function wrapErrorMiddleware(fn) {
 
     return ret;
   };
+  return copyOldProps(fn, newFn);
 }
 
 function wrap(fn) {
-  return (req, res, next) => {
+  const newFn = (req, res, next) => {
     const ret = fn.call(this, req, res, next);
 
     if (ret && ret.catch) {
@@ -24,11 +32,14 @@ function wrap(fn) {
 
     return ret;
   };
+  return copyOldProps(fn, newFn);
 }
 
 Object.defineProperty(Layer.prototype, 'handle', {
   enumerable: true,
-  get() { return this.__handle; },
+  get() {
+    return this.__handle;
+  },
   set(fn) {
     // Bizarre, but Express checks for 4 args to detect error middleware: https://github.com/expressjs/express/blob/master/lib/router/layer.js
     if (fn.length === 4) {

test.js

@@ -1,6 +1,7 @@
 require('./index.js');
 const express = require('express');
 const supertest = require('supertest');
+const assert = require('assert');
 
 describe('express-async-errors', () => {
   it('propagates routes errors to error handler', () => {
@@ -31,7 +32,6 @@ describe('express-async-errors', () => {
       throw new Error('error');
     });
 
-
     app.use((err, req, res, next) => {
       res.status(495);
       res.end();
@@ -62,4 +62,48 @@ describe('express-async-errors', () => {
       .get('/test')
       .expect(495);
   });
+
+  it('should preserve the router stack for external routes', () => {
+    const app = express();
+
+    function swaggerize(item) {
+      function describeRouterRoute(router, metaData) {
+        const lastRoute = router.stack[router.stack.length - 1];
+        const verb = Object.keys(lastRoute.route.methods)[0];
+        metaData.path = lastRoute.route.path;
+        metaData.verb = verb;
+        lastRoute.route.swaggerData = metaData;
+        metaData.described = true;
+      }
+
+      function describe(metaData) {
+        if (item.stack) {
+          describeRouterRoute(item, metaData);
+          return item;
+        }
+        describeRouterRoute(item._router, metaData);
+        return item;
+      }
+
+      item.describe = describe;
+    }
+
+    const router = express.Router();
+    swaggerize(router);
+
+    router
+      .get('/test', (req, res) => {
+        res.status(200).send('Ok');
+      })
+      .describe({ hasDescription: true });
+    app.use('/', router);
+
+    const appRouteStack = app._router.stack;
+    const someMiddlewareFunctionStack = appRouteStack[appRouteStack.length - 1];
+    const innerStack = someMiddlewareFunctionStack.handle.stack;
+    const routeData = innerStack[0].route.swaggerData;
+    assert.ok(routeData);
+    assert.equal(routeData.verb, 'get');
+    assert.equal(routeData.hasDescription, true);
+  });
 });