Is the only way to extend the Chrome dev tools via these APIs?
http://developer.chrome.com/extensions/devtools.html
http://developer.chrome.com/extensions/experimental.html
They seem pretty limited. I would want to be able to do things like filter things that have been logged / written to the console, search, pattern match, etc.
Even being able to do something like log everything but warnings (and errors) would be a simple addition I would like to do.
I can add other examples but I believe, if I'm correct, I will have to build Chrome from source?
I already run Canary and regular Chrome, I am wondering if it will run along these two?
I've read and tried to build Chrome on Mac but it didn't really work from the guide I followed, perhaps doing it on Ubuntu is easier? My goal is not to fix bugs in Chrome, just to extend it and keep it up to date with the Canary or a stable build.
Thank you.
PS: I do mostly javascript now but I used to work on systems so I am not afraid to write C++/C if I have to. However, I think the dev tools are mostly HTML/ JS themselves?
Related
So I've been coding for a while now in school, and I'm having my first introduction into a real working code base at my new job. When it comes to debugging, like if I want to find out what a certain variable is equal to, I'll often just console.log() things out and hope that something useful comes out of it.
It seems really inefficient considering how many moving parts there are in the code. Most of the time, it works eventually, but it feels so barbaric just editing the code over and over and looking at the browser's console until something useful comes out, and it feels like there has to be a better way to debug in a production environment. I am specifically using Ember.JS, but this question would apply to any framework like React or Angular or Node.
There are many tools out there to debug JS, the most "basic" being the debugger in your browser. Some tools go further also, for example VSCode has a slew of extensions that open and control the browsers debugger.
Chrome: https://developers.google.com/web/tools/chrome-devtools/javascript/
Firefox: https://developer.mozilla.org/en-US/docs/Tools/Debugger
Edge: https://learn.microsoft.com/en-us/microsoft-edge/devtools-guide/debugger
Safari also has one in the develop menu but there is no site describing it in detail - it is located in the sources pane
If you use VS Code, you can run Node apps in debug mode then select Node.js.
I looking for python/JavaScript IDE where I can put breakpoints. Currently I'm using coderunner but I can not put break points. I'll really appreciate you recommendations
I'm not an expert on Python, but I do work as a web developer and use JavaScript regularly. For that side of things, probably the easiest way is to use Chrome/Firefox debugger tools. You can do this manually by finding the line of code in the console and clicking (F12->Sources tab->Content scripts->desired script), or using the 'debugger' statement to toggle debug mode (F12->Console tab->type 'debugger' then return) and step through to what you need.
Additionally, if you're looking for an actual IDE, the only thing I've found online is the following. Here's the relevant part of that article. I've never used it (and probably never will), but there it is all the same.
Webstorm by IDEA supports setting breakpoints in the IDE. This requires launching the JavaScript debugger from IDEA. It must be configured in advance so it understands how to map JavaScript on the development server to JavaScript files in your environment. IDEA will automatically install a Chrome or Firefox plug-in to facilitate. This is pretty new technology and can be touchy.
I use PyCharm. It's a heavyweight IDE, so expect more features than you probably want if you're just getting started. It has a very good integrated debugger. You'll be able to break into both your Python and Javascript. Further, you'll see a pretty nice productivity jump with all the editing support like auto complete and intellisense. My advice is to stick with print() and logging as long as you can. For me getting a firm grasp of packages, python environments, virtualenv, command line tricks and git all before committing to the PyCharm IDE helped me adopt it with more confidence I was getting the value of all the integration.
I'm pretty new to workign with Javascript.
In most languages you can run the code quickly locally on your machine. From what I've seen, in JS you generally only use it via the browser, and so I've been uploading my code an viewing its effects in the browser. This has proven very tiresome. Also, if I mak one error, it seems like my JS/JQuery will just do NOTHING, instead of giving me a useful error, message, which is making it painfully slow to code in.
IS there some way to run JS locally to see that it is working as I go? And then only upload it to the web when I'm mostly done? What ways are there for me to do this? What ways aer there for me to unit test the Javascript locally? Say I have some JAML that should render as <p>HI</p>, how do I run this locally in a unit test?
Thanks for the help,
Alex
EDIT:
Thanks for all the great suggestions. I'll have to take a bit of time and go through them to see which ones best help me in my situation.
Since you're using jQuery, I assume that you actually want to manipulate the various elements on your page. So depending on your specific development enviroment, uploading it each time is probably the way to go anyway. If you can set up a dev enviroment on your local machine (not always possible) then go with that.
As an actual answer to your question, I suggest using Chrome's developer tools, it doesn't just have the console, but an element inspector, and a resource tracker (resource tracker is invaluable when working with JSON and AJAX, since invalid json will fail silently)
As far as I know, the firebug plugin for firefox (dont use it myself) has a similar feature set, so if you're more comfortable with that go with it.
Just remember, as a developer, your development (and debuggin) enviroment is just as important as the code that you are writing.
EDIT: Noticed that you mentioned unit testing. There are several unit testing frameworks out there for JS including one that integrates with firebug called FireUnit. Do a quick google search to find more if you want.
You don't need to upload the JS file to a server to test it. Just write an html and declare the js binding
<script
src="js/yourJSFile.js"
type="text/javascript"></script>
Edit the JS file in your favorite editor and then refresh the page to test it.
For unit testing the best option is Selenium. It allows you to record an interaction with the browser and then play it back.
You can use Firebug with Firefox to debug JS, and Google Chrome has a debugger built-in (use the Tools -> Developer Tools menu).
You can run Javascript from the local file on your machine in your browser, so you can skip the uploading step.
Also, I'd recommend using Firefox/Firebug combo for developing Javascript as it will be very handy, especially for the part you mentioned about not seeing what's going wrong with your code.
Even if you upload your javascript it gets downloaded back to you as soon as you visit the webpage that invoques it. Its run client side always. So stick to local and use firebug as the others have said. Google`s developer tool is quite nice too.
In the browser if you open the developer tools, follow the following steps:
1) Navigate to sources
2) Under sources, click snippet and open run.js
3) You can use run.js to write as much code as you want and run it locally only to see if your code is working or not (it will give you output on the console)
4) Also you can get used to some keyboard shortcuts to make it faster for you.
5) For small javascript codes, you can navigate to console and run your code there
If you want to do unit testing with Javascript there are extension of Firebug that can help you with that. I haven't try any of them, so I can't really tell you which one are worth considering, but you can easily find them if you search for the keyword "Firebug unit testing" on Google.
What seems to be comming on top is FireUnit. You can find some information about how it works here.
Consider Spider Monkey, which is a javascript engine separate from a browser. If what you are developing does not involve rendering to a webpage or can be separated from the rendering code (good practice!), then this could be useful.
I prefer Chrome to Firefox and I just found Web Server for Chrome.
It's just a Google App that quickly sets up a web server for you and will be set up anywhere you are logged into Chrome. It only allows file access to your current devices, or if you specify, other devices only on the current LAN.
You just point it to the directory with your index.html file and type http://127.0.0.1:8887 in your browser.
Additionally to the answers given you can use Jasmine for automated testing.
A tutorial that seems to help get started with automated testing on Jasmine is provided by Evan Hahn.
I used it and for me it works like a charm. Especially if test driven development is what you are going for!
Warning: I have very little JavsScript experience.
In my past programming experience, I usually have a standalone interpreter/compiler, a text editor and a command line to compile/run my software or my tests (I love test driven development). I really like it this way, since I have the feeling of being in complete control over the tools. However, editing JavaScript I need to put statements in a text file , open my web browser and click on reload. I don't feel comfortable with it, as I cannot really see what is going on (besides some alert boxes).
Can you suggest me (I'm on a Mac) another workflow? Perhaps with a debugger? Is there a standalone JavaScript interpreter?
Opera, Internet Explorer, Chrome and Safari all come with good debuggers built in (links go to information about the debuggers).
They are all modeled after Firebug, an extension for Firefox (and the existence of which is why Firefox doesn't have one built in).
Firebug has a javascript debugger,a console, and a command line. I couldn't live without it.
Firebug is a firefox extension. They do have firebug lite for other browsers.
As far as workflow goes... Ctrl+S, Alt+Tab, F5 over and over again.
I would throw in validation there as well, use jslint either via one of the available command line tools, or via eg. Aptana which has builtin validation.
Setting up a simple build script is also preferable. I do it with all my projects and lets it handle validation, conditional code (debug versions etc) and minifying.
This http://github.com/oyvindkinsey/easyXDM/blob/master/build.xml is for instance the build setup for easyXDM. It does everything from pushing out new versions to the website to creating documentation and zip files..
I have a few scripts on a site I recently started maintaining. I get those Object Not Found errors in IE6 (which Firefox fails to report in its Error Console?). What's the best way to debug these- any good cross-browser-compatible IDEs, or javascript debugging libraries of some sort?
There's no cross-browser JS debugger that I know of (because most browsers use different JS engines).
For firefox, I'd definitely recommend firebug (http://www.getfirebug.com)
For IE, the best I've found is Microsoft Script Debugger (http://www.microsoft.com/downloads/details.aspx?familyid=2f465be0-94fd-4569-b3c4-dffdf19ccd99&displaylang=en). If you have Office installed, you may also have Microsoft Script Editor installed. To use either of these, you need to turn on script debugging in IE. (uncheck Tools -> Internet Options -> Advanced -> Disable Script debugging).
You could also use Firebug Lite - which will work in IE & Opera. It's an external lib that will help you track down problems. It's sometimes more convenient than dealing with the MS Script Debugger.
Firebug
It's only for firefox but it should let you figure out what's happening on IE especially once you have the script line numbers.
You can use Visual Studio and enable debugging in browser
You can install FireBug plugin for Firefox, it's really good!
You can try to install IE8 beta 2 and use it in compatibility mode with built-in debugger.
Also in any line of your JS code you can write
debugger;
and this will be threated as breakpoint for any of the debug tools you use.
Cheers!
Aptana Studio provides JavaScript debugging for Firefox and IE
Firebug is the best all around client-side debugger. I frequently use it to debug CSS code as well as javascript. It allows you to easily find offending areas of code. I especially like the ability to modify tag attributes in the firebug pane and see the effects immediately before committing. Very useful for anyone designing websites.
You could use this tool apparently - Microsoft Script Debugger
Personally I try to go through the code and figure out what's going on - it gives you the line number where it goes wrong right?
To make the Microsoft Script Debugger more user friendly (and to add javascript error messages that actually are helpful to IE), I highly recommend Companion.JS.
Firebug seems to be the most useful so far. When a page is running on firebug, it can be very handy to log messages into firebug via javascript calls to console.log('your log message'); but don't execute that code in IE since the console object is only in scope when firebug is running.
For IE, other folks have mentioned the Script Debugger. Although it is not primarily for javascript debugging, it can be useful to also add the IE developer toolbar, which allows you to easily and dynamically inspect the style and other properties of your page's DOM.
In response to mopoke, for IE6 you definitely want to use Visual Studio for debugging if you can get it. For all intents and purposes, the MS script debugger is useless. You're better off using some form of tracing (not alerts) than using the MS script debugger. Dojo Toolkit, for instance, provides a debug console for tracing, but you can write your own by dumping messages to a secondary window or div.
The script debugger needlessly prompts you on each error in IE6 and even then doesn't give you enough state context to make it useful in a sufficiently complex JS app. Visual Studio is more tightly integrated and much friendlier. Just my experience.