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Trying to run hello world JavaScript program on visual studio but keep getting 'document' is undefined

I've watched videos and when people run this it works just fine. I also tried console.log and I get-- 'console' undefined. I have node.js installed

document is not a built-in part of JavaScript. It is part of the Web API provided by browsers which you get when you load your JS by using a <script> element in an HTML document in a web browser. You aren't doing that, and document doesn't have a log method anyway.
You're running your JS using Windows Script Host, which isn't that. WSH does not have a document.
You probably want either:
the WriteLine method
to not use WSH (Browsers and Node.js being more common ways to run JS)

You aren't running in a browser, there is no document (plus, it'd be console.log there too). You are running in Windows Script Host, you can use WScript.Echo instead. But I'd rather recommend you to run your code in a browser or node.js anyway, WSH isn't a very useful environment for learning modern JavaScript.
You wrote you have node.js installed, so the issue could be that you simply used the wrong command: it should be node and not start!

Debugging server side with node.js

I have a burning question in my head regarding debugging, you see when I am writing Javascript client side I can go to Chrome's console and track my variables and objects etc to see what is happening with my code better.. I am just not able to get my head around about how can we do the same on the server side (node js)? Let's say my front end submitted a form to my express server, how do I go about checking if for instance the req object even received it or not? where do I go about checking variables and objects (debugging) server side code? I definitely can't do it on console of browser as the code exists and executes on the server side so I can't access server side objects etc through browser's console.

You can still do console.log(). It'll print to the screen where you run the server. However, it's not as good as walking through the code with debugger which you can set breakpoints and do lots of other things debuggers can do. I've used both webstorm's debugger and node-inspector.
You might want to look into node-inspector. The debugger is like Chrome's Dev-Tool, which you might be familiar with. The link below provides everything from installation to tutorials.
https://github.com/node-inspector/node-inspector

Node comes with a REPL (Read-Eval-Print-Loop). It works a bit like the console of chrome but requires a bit of configuration and set up of it's scope.
Here is an example: http://derickbailey.com/2014/07/02/build-your-own-app-specific-repl-for-your-nodejs-app/

if you do console.log to variables and objects you can see it on you command prompt from where you are running your server

The console.log() has 2 kinds:
When it write in the client codes. It will console the message on your brower.
When it write in the server codes. It will console the message on your editor such as Webstorm.
Suggest use debug to check variables and objects instead of using console.log() because it's more convenient.

You might want to consider webstorm. It has advanced debugging support built-in for nodejs which allows you to set breakpoints just like in Chrome's debugging tools.

SocketIO + PhantomJS emit not working

I am having a pretty specific problem but I hope people can point me in the right direction for how to debug or even fix it. I am trying to write a local client which can run and test a webpage I had built which uses SocketIO.
I am running Phantom with the command line option --web-security=false since otherwise no in or out connections are legal as my local tester is not considered part of the same origin as my website I am testing (had to fix that before the listening would work).
Using PhantomJS I can't get the emit function from SocketIO to work. It just fails silently without any error. I know the socket is validly connected because it can listen to incoming events just fine (so the on() method works). I can run the same emitting code in a web browser and it works just fine.
Does anyone know alternatives to emit(), what lower level things emit() invokes that maybe I could patch, or how I should test things next? Any help is appreciated.

After a lot of research it looks like this form of sockets simply aren't yet supported in phantomjs. When the new 2.0 releases they are supposed to be but until then other options are better. I tried to find a shim for a while but was unsuccessful.
In the end, I instead used node.js to run the main script, make the socket connections and then used the phantomjs node module to do the browser interactions rather than running the script as a pure phantom script. This meant that the api interaction logic got pushed to the node application and the phantom code was just about interacting with the page but I was able to achieve the testing goal this way so I count it as success.

Is there a way to automate the testing of chrome extensions? [duplicate]

I'm going to write bunch of browser extensions (the same functionality for each popular browser). I hope, that some of the code will be shared, but I'm not sure about this yet. For sure some of extensions will use native API. I have not much experience with TDD/BDD, and I thought it's good time to start folowing these ideas from this project.
The problem is, I have no idea how to handle it. Should I write different tests for each browser? How far should I go with these tests? These extensions will be quite simple - some data in a local storage, refreshing a page and listening through web sockets.
And my observation about why is it hard for me - because there is a lot of behaviour, and not so much models, which are also dependent on a platform.

I practise two different ways of testing my browser extensions:
Unit tests
Integration test
Introduction
I will use the cross-browser YouTube Lyrics by Rob W extension as an example throughout this answer. The core of this extension is written in JavaScript and organized with AMD modules. A build script generates the extension files for each browser. With r.js, I streamline the inclusion of browser-specific modules, such as the one for cross-origin HTTP requests and persistent storage (for preferences), and a module with tons of polyfills for IE.
The extension inserts a panel with lyrics for the currently played song on YouTube, Grooveshark and Spotify. I have no control over these third-party sites, so I need an automated way to verify that the extension still works well.
Workflow
During development:
Implement / edit feature, and write a unit test if the feature is not trivial.
Run all unit tests to see if anything broke. If anything is wrong, go back to 1.
Commit to git.
Before release:
Run all unit tests to verify that the individual modules is still working.
Run all integration tests to verify that the extension as whole is still working.
Bump versions, build extensions.
Upload update to the official extension galleries and my website (Safari and IE extensions have to be hosted by yourself) and commit to git.
Unit testing
I use mocha + expect.js to write tests. I don't test every method for each module, just the ones that matter. For instance:
The DOM parsing method. Most DOM parsing methods in the wild (including jQuery) are flawed: Any external resources are loaded and JavaScript is executed.
I verify that the DOM parsing method correctly parses DOM without negative side effects.
The preference module: I verify that data can be saved and returned.
My extension fetches lyrics from external sources. These sources are defined in separate modules. These definitions are recognized and used by the InfoProvider module, which takes a query, (black box), and outputs the search results.
First I test whether the InfoProvider module functions correctly.
Then, for each of the 17 sources, I pass a pre-defined query to the source (with InfoProvider) and verify that the results are expected:
The query succeeds
The returned song title matches (by applying a word similarity algorithm)
The length of the returned lyrics fall inside the expected range.
Whether the UI is not obviously broken, e.g. by clicking on the Close button.
These tests can be run directly from a local server, or within a browser extension. The advantage of the local server is that you can edit the test and refresh the browser to see the results. If all of these tests pass, I run the tests from the browser extension.
By passing an extra parameter debug to my build script, the unit tests are bundled with my extension.
Running the tests within a web page is not sufficient, because the extension's environment may differ from the normal page. For instance, in an Opera 12 extension, there's no global location object.
Remark: I don't include the tests in the release build. Most users don't take the efforts to report and investigate bugs, they will just give a low rating and say something like "Doesn't work". Make sure that your extension functions without obvious bugs before shipping it.
Summary
View modules as black boxes. You don't care what's inside, as long as the output matches is expected or a given input.
Start with testing the critical parts of your extension.
Make sure that the tests can be build and run easily, possibly in a non-extension environment.
Don't forget to run the tests within the extension's execution context, to ensure that there's no constraint or unexpected condition inside the extension's context which break your code.
Integration testing
I use Selenium 2 to test whether my extension still works on YouTube, Grooveshark (3x) and Spotify.
Initially, I just used the Selenium IDE to record tests and see if it worked. That went well, until I needed more flexibility: I wanted to conditionally run a test depending on whether the test account was logged in or not. That's not possible with the default Selenium IDE (it's said to be possible with the FlowControl plugin - I haven't tried).
The Selenium IDE offers an option to export the existing tests in other formats, including JUnit 4 tests (Java). Unfortunately, this result wasn't satisfying. Many commands were not recognized.
So, I abandoned the Selenium IDE, and switched to Selenium.
Note that when you search for "Selenium", you will find information about Selenium RC (Selenium 1) and Selenium WebDriver (Selenium 2). The first is the old and deprecated, the latter (Selenium WebDriver) should be used for new projects.
Once you discovered how the documentation works, it's quite easy to use.
I prefer the documentation at the project page, because it's generally concise (the wiki) and complete (the Java docs).
If you want to get started quickly, read the Getting Started wiki page. If you've got spare time, look through the documentation at SeleniumHQ, in particular the Selenium WebDriver and WebDriver: Advanced Usage.
Selenium Grid is also worth reading. This feature allows you to distribute tests across different (virtual) machines. Great if you want to test your extension in IE8, 9 and 10, simultaneously (to run multiple versions of Internet Explorer, you need virtualization).
Automating tests is nice. What's more nice? Automating installation of extensions!
The ChromeDriver and FirefoxDriver support the installation of extensions, as seen in this example.
For the SafariDriver, I've written two classes to install a custom Safari extension. I've published it and sent in a PR to Selenium, so it might be available to everyone in the future: https://github.com/SeleniumHQ/selenium/pull/87
The OperaDriver does not support installation of custom extensions (technically, it should be possible though).
Note that with the advent of Chromium-powered Opera, the old OperaDriver doesn't work any more.
There's an Internet Explorer Driver, and this one does definitely not allow one to install a custom extension. Internet Explorer doesn't have built-in support for extensions. Extensions are installed through MSI or EXE installers, which are not even integrated in Internet Explorer. So, in order to automatically install your extension in IE, you need to be able to silently run an installer which installs your IE plugin. I haven't tried this yet.

Testing browser extensions posed some difficulty for me as well, but I've settled on implementing tests in a few different areas that I can invoke simultaneously from browsers driven by Selenium.
The steps I use are:
First, I write test code integrated into the extension code that can be activated by simply going to a specific URL. When the extension sees that URL, it begins running the tests.
Then, in the page that activates the testing in the extension I execute server-side tests to be sure the API performs, and record and log issues there. I record the methods invoked, the time they took, and any errors. So I can see the method the extension invoked, the web performance, the business logic performance, and the database performance.
Lastly, I automatically invoke browsers to point at that specific URL and record their performance along with other test information, errors, etc on any given client system using Selenium:
http://docs.seleniumhq.org/
This way I can break down the tests in terms of browser, extension, server, application, and database and link them all together according to specific test sets. It takes a bit of work to put it all together, but once its done you can have a very nice extension testing framework.
Typically for cross-browser extension development in order to maintain a single code-base I use crossrider, but you can do this with any framework or with native extensions as you wish, Selenium won't care, it is just driving the extension to a particular page and allowing you to interact and perform tests.
One nice thing about this approach is you can use it for live users as well. If you are providing support for your extension, have a user go to your test url and immediately you will see the extension and server-side performance. You won't get the Selenium tests of course, but you will capture a lot of issues this way - very useful when you are coding against a variety of browsers and browser versions.

Headless node.js javascript browser with screenshot capability?

Are there any headless browsers for node.js that support dumping a rendered page out to a file? I know phantomjs supports rendering to a file, but it doesn't run on node.js. I know zombie.js is a node.js headless browser, but it doesn't support rendering to a file.

I doubt you will find anything that is going to work as well as phantomjs. I would just treat the rendering as an async backend process and execute phantom in a subprocess from your main node.js process and call it a day. Rendering a web page is HARD, and since phantom is based on WebKit, it can actually do it. I don't think there will ever be a node library that can render a web page to a graphic file that isn't built upon an existing browser rendering engine. But maybe one day phantomjs will integrate more seamlessly with node.

Try nightmare, it uses the electron, it is way faster than phantomjs, and it's API easy and uses modern ES6 javascript.

This might look like a solution with a little bit overhead...
You can use the Mozilla Firefox with the MozRepl plugin. Basically this plugin gives you a telnet port to your Firefox which allows you to control the browser from the outside. You can open URLs, take screenshots, etc.
Running the Firefox with the Xvfb server will run it in headless mode.
Now you just have to control the browser from the outside with node.js. I've seen a few examples where someone has implemented a http alike interface inside the chrome.js of Firefox. So you can run a http command to get a screenshot. You can then use http calls from node.js. This might look strange, it actually is but might work well for you.
http://hyperstruct.net/2009/02/05/turning-firefox-into-a-screenshot-server-with-mozrepl/
I'm running a slightly modified version in production with Perl Mojolicious in async mode to trigger the screenshots. However, there is a small problem. When plugins are required they do work, however Flash usually gets activated when it's in the visible area, this won't happen so movies/flash things might not get initialized.

You might find this helpful, though it's not javascript specific.
There is a webkit-based tool called "wkhtmltopdf" that I understand includes javascript support using the QT web-kit widget. It outputs a visual representation ("screenshot" if you will) of the page in PDF format.
FWIW, there are also PHP bindings for it here: php-wkthmltox

The Chrome dev team has released Puppeteer which can be used in node. It uses Chrome with the headless option.

There's a project called Node-Chimera. Although it's not as mature as Phantomjs, it has all the features you have mentioned: it runs on native Nodejs, and allows you to render pages to a file. Repository is here: https://github.com/deanmao/node-chimera. It has examples to do exactly what you need.