allow marko/express to be used as middleware

express.js

@@ -2,8 +2,24 @@ require('./runtime/env-init');
 
 var assign = require('object-assign');
 var express = module.parent.require('express');
-var response = express.response;
+patchResponse(express.response);
+delete require.cache[__filename];
 
+module.exports = function markoAppMiddleware() {
+    var sacrificialApp = express();
+
+    sacrificialApp.once('mount', function onmount(parent) {
+        // Patch the response
+        patchResponse(parent.response);
+
+        // Remove sacrificial express app
+        parent._router.stack.pop();
+    });
+
+    return sacrificialApp;
+}
+
+function patchResponse(response) {
     response.marko = response.marko || function(template, data) {
         if(typeof template === 'string') {
             throw new Error(
@@ -30,5 +46,4 @@ response.marko = response.marko || function(template, data) {
 
         template.render(data, res);
     };
-
-delete require.cache[__filename];
+}

test/autotests/express/headers/test.js

@@ -1,10 +1,10 @@
 exports.createApp = function(express, markoExpressPath) {
     var app = express();
-
-    require(markoExpressPath);
+    var markoExpress = require(markoExpressPath);
 
     app.locals.foo = 'FOO';
 
+    app.use(markoExpress());
     app.use(function(req, res, next) {
         res.locals.bar = 'BAR';
         next();

test/autotests/express/incorrect-usage/test.js

@@ -1,7 +1,8 @@
 exports.createApp = function(express, markoExpressPath) {
-    require(markoExpressPath);
-
     var app = express();
+    var markoExpress = require(markoExpressPath);
+
+    app.use(markoExpress());
 
     return app;
 };

test/autotests/express/locals/test.js

@@ -1,10 +1,10 @@
 exports.createApp = function(express, markoExpressPath) {
-    require(markoExpressPath);
-
     var app = express();
+    var markoExpress = require(markoExpressPath);
 
     app.locals.foo = 'FOO';
 
+    app.use(markoExpress());
     app.use(function(req, res, next) {
         res.locals.bar = 'BAR';
         next();

test/autotests/express/priority/test.js

@@ -1,12 +1,12 @@
 exports.createApp = function(express, markoExpressPath) {
-    require(markoExpressPath);
-
     var app = express();
+    var markoExpress = require(markoExpressPath);
 
     app.locals.foo = 'APP';
     app.locals.bar = 'APP';
     app.locals.baz = 'APP';
 
+    app.use(markoExpress());
     app.use(function(req, res, next) {
         res.locals.foo = 'RES';
         res.locals.bar = 'RES';