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POUnable to catch exception from within a supertest app request
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copied!<p>Code example shown here: <a href="https://gist.github.com/sebinsua/8118001" rel="nofollow">https://gist.github.com/sebinsua/8118001</a></p> <p>(There are three failures and two passes. I would like there to be four failures and one success.)</p> <p>It's possible to catch AssertionErrors with mocha if thrown from normal functions, but as soon as the functions are called from within a supertest wrapped app, I no longer am able to detect them. This is annoying as I wanted to be able to inject certain assertions into my express app which I could then test. (I am testing a middleware with side-effects that I wish to test, if you can tell me how to mockup request and response objects that also solves my problem.)</p> <p>Because I am able to access a spy, I know that it's nothing to do with the state being inaccessible.</p> <p>However, I notice that node.js/express.js/supertest automatically convert uncaught exceptions to an error message in the response. Perhaps that is what is stopping them from being caught by the mocha test?</p> <p><strong>Edit</strong></p> <p>I just tested out the code to immediately below to see if this is a general http.createServer() problem. It isn't. This means something is happening at either connect, express.js, supertest or superagent levels. (These snippets of code only work half-of-the-time btw...)</p> <pre><code>var http = require("http"), assert = require('assert'); describe('Really crazy test of assertions', function () { it("cannot create a server which throws an assertion error", function (done) { var port = Math.floor(Math.random() * 9999) + 1; http.createServer(function (req, res) { console.log("On the server."); throw new assert.AssertionError({ message: "Can I throw an assertion error? "} ); res.end("HEY"); }).listen(port); setTimeout(function () { console.log("On the client."); http.get('http://localhost:' + port + '/', function (res) { console.log("Will I receive the error message on the client's side? No."); console.log(res); }); done(); }, 1000); }); }); </code></pre> <p>It looks like an express problem (see below) - I noticed the AssertionError wasn't appearing in red text (like it would in the case of being picked up by Mocha.)</p> <pre><code>var http = require("http"), express = require("express"), assert = require('assert'); var app = express(); describe('Really crazy test of assertions', function () { it("cannot create a server which throws an assertion error", function (done) { var port = Math.floor(Math.random() * 9999) + 1; app.get('/', function (req, res) { console.log("On the server."); throw new assert.AssertionError({ message: "Can I throw an assertion error? "} ); res.end('HEY'); }).listen(port); setTimeout(function () { console.log("On the client."); http.get('http://localhost:' + port + '/', function (res) { console.log("Will I receive the error message on the client's side? No."); console.log(res); }); done(); }, 1000); }); }); </code></pre> <p>In short my question is, how do I get A to behave like B?</p> <p><strong>A</strong></p> <pre><code>var http = require("http"), express = require("express"), assert = require('assert'); var app = express(); var port = Math.floor(Math.random() * 9999) + 1; app.get('/', function (req, res) { console.log("On the server."); throw new assert.AssertionError({ message: "Can I throw an assertion error? "} ); res.send('HEY'); }).listen(8888); </code></pre> <p><strong>B</strong></p> <pre><code>var http = require("http"), assert = require('assert'); http.createServer(function (req, res) { console.log("On the server."); throw new assert.AssertionError({ message: "Can I throw an assertion error? "} ); res.end("HEY"); }).listen(8888); </code></pre> <p><strong>UPDATE</strong></p> <p>Line 192 of senchalab's connect at /lib/proto.js is where this is all going wrong. There is a try-catch and this passes my error into the next middleware which continues to do the same thing until either a 4-arity middleware handles it or there are no more middleware in which it runs some fallback code to automatically print to the screen and discard the exception...</p> <p>I've no idea what I can do to get it to throw my error again, unless I am able to overwrite the handle method someway or other.</p>

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