👍🎉 First off, thanks for taking the time to contribute! 🎉👍
We respect your time and want to help you make the most of it as you learn more about this project.
What should I know before I get started?
The developer tools in most major browsers are just web applications. They are HTML & JS rendered by the browser and talk to the browser itself through an API that gives access to the page internals. This project is a brand new web application interface for JavaScript debugging designed for browsers and JS environments.
The debugger.html project is a JavaScript debugger built from the ground up using modern web application technologies. It is designed first for debugging Firefox but also for working with projects like Chrome and Node. The name debugger.html was chosen because this debugger interface is being written using modern web technologies where as the previous Firefox debugger was written in XUL.
devtools.html is the larger umbrella initiative that encompasses the debugger.html and several other devtools projects. The devtools.html project claims its origin from a demo for a Mozilla (Dec 2016) work week in Orlando, FL USA where the team worked under a tight deadline to provide a proof of concept of the Firefox developer tools running in pure HTML; even outside of Firefox. The code for that demo can be found on Github under @joewalker/devtools.html.
From that original demo the devtools.html project has progressed quite a bit. To learn more about it please read the devtools.html proposal document and take a look at the devtools.html meta bug for tracking progress.
The debugger.html project is targeted to land in Firefox for Firefox 52. However if you're looking to work directly on the DevTools project which ships developer tools for Firefox and Firefox Developer Edition right now you can find more information on the Mozilla wiki DevTools / Get Involved.
The debugger.html is a web application that makes a WebSocket connection to a debuggable target like the JavaScript engine of a web browser. The web application then interprets data and sends commands to the JS engine to manage the debugging environment; for example by creating a breakpoint or displaying that the JS engine is paused at a breakpoint.
First we need to get the web application running. Within the source code directory, from the command line run these commands.
npm install
- Install dependenciesnpm start
- Start development web server
Then, because npm start
will remain running, from another terminal window you can open http://localhost:8000 in your browser or type the following:
open http://localhost:8000
- Open in any modern browser
The following are instructions for getting Firefox, Chrome, and Node running with remote debugging turned on. Remote debugging is necessary for the debugger.html project to connect to these targets.
The following command will automatically start a remote debuggable version of Firefox using a temporary profile and set all the necessary preferences for you. This command runs Firefox in a selenium environment that is great for quick testing.
$ npm run firefox
- Restart your development server
ctrl+c
in the Terminal and runnpm start
again - Reload
localhost:8000
(you should now see a Firefox tabs section)
Command line option
Here are the instructions for running Firefox from the command line (MacOS + Firefox shown):
$ /Applications/Firefox.app/Contents/MacOS/firefox-bin --start-debugger-server 6080 -P development
If this command doesn't work for your OS or Firefox version see the other Firefox commands for running in a debuggable state
NOTE: The Firefox started from the npm run
command automatically sets the following necessary flags which you will need to do manually if you ran Firefox from the command line.
Navigate to about:config
and accept any warning message. Then search for the following preferences and double click them to toggle their values to the following.
devtools.debugger.remote-enabled
totrue
devtools.chrome.enabled
totrue
devtools.debugger.prompt-connection
tofalse
Once you have Firefox running in a debuggable state go back up to instructions for restarting your development server.
Start by running Chrome with remote debugging turned on, this command also creates a new temporary profile
/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --remote-debugging-port=9222 --no-first-run --user-data-dir=/tmp/chrome-dev-profile http://localhost:8000/todomvc/
If this command doesn't work for your OS or Chrome version see the other Chrome commands for running in a debuggable state
Now turn on Chrome debugging in the config by creating a local config file
- Edit the
config/local.json
you just created to change the value ofchrome.debug
to betrue
"chrome": {
"debug": true
}
- Restart your development server by typing
ctrl+c
in the Terminal and runnpm start
again - Reload
localhost:8000
(you should now see a Chrome tabs section)
Debugging node requires at least node v6.3.0 and running node with the inspect
flag turned on. Here's what running node looks like when running an example server.js
file.
$ node --inspect server.js
With node running in inspect mode go to your browser running localhost:8000
and click connect to Node
If you find an issue with the code please do file an issue and tag it with the label bug. We'll do our best to review the issue in a timely manner and respond.
We are actively investigating ways of support enhancement requests in the project so these instructions are subject to change. For now please create an issue, tag it with the enhancement label and we will attempt to respond.
Documentation is as important as code and we need your help to maintain clear and usable documentation. If you find an error in here or other project documentation please file an issue and tag it with the label docs.
We have a number of tools to help you with your code contributions, the following describes them all and how you can make use of them.
If this is your first time contributing any code take a look through the first-timers-only
issues:
- first-timers-only - issues which should have clear expectations and a mentor to help you through
If you've contributed to an open source project before, but would like to help this one please take a look through the up for grabs
issues:
- up for grabs - issues which should have clear requirements and a difficulty level set as a label
To begin your work make sure you follow these steps:
- Fork this project
- Create a branch to start your work
git checkout -b your-feature-name
- Commit your work
- Create a pull request
- Include screenshots and animated GIFs in your pull request whenever possible.
- List any steps necessary to trigger the feature you've created or bug you are fixing
- Always run the tests locally before creating your PR
- Request review from @jasonLaster or @jlongster by mentioning their names in the PR
Hot Reloading watches for changes in the React Components JS and CSS and propagates those changes up to the application without changing the state of the application. You want this turned on.
To enabled Hot Reloading:
- Create a local config file if you don't already have one
- Edit the
config/local.json
you just created to change the value ofhotReloading
to betrue
{
"hotReloading": true
}
- Restart your development server by typing
ctrl+c
in the Terminal and runnpm start
again
Read more about Hot Reloading
Your code must pass all tests to be merged in. Your tests should pass locally before you create a PR and the CI should run an automated test that also passes.
Here's how can run all the unit tests, lints, and integration tests at once:
$ npm run test-all
npm test
- Run tests headlessly- These are the basic unit tests which must always pass
npm run mocha-server
- Run tests in the browser once you openhttp://localhost:8003
- This runs tests in the browser and is useful for fixing errors in the karma tests
npm run cypress
- Run tests headlesslynpm run cypress-intermittents
- Runs tests 100 times and writes the output to cypress-run.logcypress open
- Run tests in the browser
Learn more about Cypress in our integration tests docs.
Run all of lint checks (JS + CSS) run the following command:
$ npm run lint
We use Stylelint to maintain our CSS styles. The .stylelintrc file contains the style definitions, please adhere to those styles when making changes.
To test your CSS changes run the command:
$ npm run lint-css
We use eslint to maintain our JavaScript styles. The .eslintrc file contains our style definitions, please adhere to those styles when making changes.
To test your JS changes run the command:
$ npm run lint-js
Storybook is our local development and testing utility that allows you to see how an individual component like the breakpoint list view or the call stack view react to any changes to style and code you've made.
$ npm run storybook
Read more information in storybook docs
All default config values are in config/development.json
, to override these values you need to create a local config file.
Here are the most common development configuration options:
logging
firefoxProxy
Enables logging the Firefox protocol in the terminal runningnpm start
chrome
debug
Enables listening for remotely debuggable Chrome browsers
hotReloading
enables Hot Reloading of CSS and React
For a list of all the configuration options see the config/README
- Copy the
config/development.json
toconfig/local.json