How to make an AJAX call hang

Question

I'm trying to test the behavior of my site when scripts take too long to load. I know how to completely block the request so that it returns a 404 by adding something to the host file, but not sure how to force the request to just not complete.

Example,

127.0.0.1 translate.google.com # this blocks google translate from loading (404)

Instead, I'd like to make translate.google.com not respond for x seconds.

I'm using requirejs to load my scripts and I'm noticing that timeout behaves differently than 404.

I added a module to allow google translate to be optionally required, and when I block it via host file, the site behaves correctly. When the script times out, the site fails to load.

// http://stackoverflow.com/questions/14164610/requirejs-optional-dependency

define("optional", [], {
    load: function (moduleName, parentRequire, onload, config) {
        var onLoadSuccess = function (moduleInstance) {
            // Module successfully loaded, call the onload callback so that
            // requirejs can work its internal magic.
            onload(moduleInstance);
        }

        var onLoadFailure = function (err) {
            // optional module failed to load.
            var failedId = err.requireModules && err.requireModules[0];
            console.warn("Could not load optional module: " + failedId);

            // Undefine the module to cleanup internal stuff in requireJS
            requirejs.undef(failedId);

            // Now define the module instance as a simple empty object
            // (NOTE: you can return any other value you want here)
            define(failedId, [], function () { return {}; });

            // Now require the module make sure that requireJS thinks 
            // that is it loaded. Since we've just defined it, requirejs 
            // will not attempt to download any more script files and
            // will just call the onLoadSuccess handler immediately
            parentRequire([failedId], onLoadSuccess);
        }

        parentRequire([moduleName], onLoadSuccess, onLoadFailure);
    }
});

Could you elaborate what you are trying to test? You could simply delay calling the `onload` method in your `onLoadSuccess` callback handler using something like `setTimeout(() => onload(moduleInstance), 4 * 1000)` for a 4s delay. — alpeware, May 05 '17 at 14:34
Trying to test what happens when a script timesout. when it returns 404, it behaves correctly, when it timesout, it does not behave correctly. — MPavlak, May 05 '17 at 15:21

score 0 · Accepted Answer · edited May 23 '17 at 12:26

0

You need to test it with a website you have control over. Simplest solution is to use your own localhost with a little script that waits for several seconds.

A short PHP example to wait for 30 seconds would look like:

<?php
  sleep(30);
  echo 'DONE';

Just increase the seconds to sleep until your application has a timeout.

Here is another solution in Node.js

UPDATE:

Next step is to redirect the url you want to timeout in your host file (as in your question):

127.0.0.1 translate.google.com

Run a local Apache server (127.0.0.1 is standard for localhost) and put the following .htaccess file in your apache root (normally "htdocs"):

DirectoryIndex index.php
RewriteEngine on
RewriteRule ^(.*)$ index.php [QSA,L]

Then just put the PHP example from above in a file named index.php in your root (normally "htdocs").

Then your local server should respond to the call and you can adjust the response time until you have your timeout.

edited May 23 '17 at 12:26

Community

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1

answered May 05 '17 at 14:38

dcman

91
1
7

Technically, I could do this. However, I would not prefer to move all the external scripts into my project just to test what happens when they fail to respond. – MPavlak May 05 '17 at 15:22
As long as your application runs in your browser you don't have to. You can adjust your local host file so that the desired request is redirected to your localhost (127.0.0.1). – dcman May 05 '17 at 15:41
pointing local for scripts which i'm not serving returns a 404. it doesn't hang – MPavlak May 05 '17 at 15:43
OK, I updated my answer how you can avoid the 404 and serve your local timeout script instead. Hope it helps. – dcman May 05 '17 at 16:15
I do believe this will work. However, I'm using C# and asp.net not php and apache. do you know to make this work using something more friendly to that stack? – MPavlak May 05 '17 at 16:17
I am no expert for C# and IIS configuration. But it should be the same principle: Configure your local IIS so it serves your request with a local script. And then put a local script there that produces the timeout. – dcman May 05 '17 at 16:21
Yep, I get the principle, just not positive how to do it. If no one volunteers an IIS based answer I'll give you the check. – MPavlak May 05 '17 at 17:04

How to make an AJAX call hang

1 Answers1