tl;dr: join Discord, be courteous, follow the steps below to set up a development environment; if you stick around and contribute, you can join the team and get commit access.
If you are here because you just want to test the bleeding-edge (unreleased) DevTools functionality, follow our beta testing guidance.
We gladly accept contributions via GitHub pull requests! We encourage you to read the
Welcome remarks in the Flutter
framework's contributing guide, as all of that information applies to contributing to the flutter/devtools
repo as well.
We prioritize reviewing PRs that address issues with the following labels:
good-first-issue: Small and easy issues that can be tackled by a first-time contributor.contributions-welcome: Issues of any size or difficulty that we consider high-priority fixes.
We communicate primarily over GitHub and Discord on the #hackers-devtools channel.
Before contributing code:
-
Complete the Contributor License Agreement. You can do this online, and it only takes a minute.
-
Review the DevTools style guide, which uses a combination of Dart and Flutter best practices.
Before setting up your DevTools environment, please make sure you have
cloned the Flutter SDK from GitHub
and added the included flutter and dart executables to your PATH environment variable (see Flutter
instructions for how to update your PATH).
Typing which flutter and which dart (or where.exe flutter and where.exe dart for Windows)
into your terminal should print the path to the binaries from the Flutter SDK you cloned from GitHub.
Be sure to run flutter doctor -v to ensure your Flutter environment is set up correctly.
If you plan to develop on macOS or run a test app on an iOS simulator, you will need
to ensure CocoaPods is setup correctly.
-
Fork the DevTools repo to your own Github account, and then clone it using SSH.
- If you haven't already, you may need to generate a new SSH key to connect to Github with SSH.
- Make sure to configure Git to keep your fork in sync with the upstream DevTools repo.
-
Ensure that you have access to the DevTools repo management tool exectuable,
dt:- Run
flutter pub geton thedevtools/tooldirectory - Add the
devtools/tool/binfolder to yourPATHenvironment variable:- MacOS Users
-
add the following to your
~/.zshrcfile (or~/.bashrc,~/.bash_profileif you use Bash), replacing<DEVTOOLS_DIR>with the absolute path to your DevTools repo:export PATH=$PATH:<DEVTOOLS_DIR>/tool/bin
-
- Windows Users
- Open "Edit environment variables for your account" from Control Panel
- Locate the
Pathvariable and click Edit - Click the New button and paste in
<DEVTOOLS_DIR>/tool/bin, replacing<DEVTOOLS_DIR>with the absolute path to your DevTools repo.
- MacOS Users
Explore the commands and helpers that
dtprovides by runningdt -h. - Run
-
Optional: enable and activate DCM (Dart Code Metrics) - see the DCM section below
We recommend using VS Code for your DevTools development environment because this gives you
access to some advanced development and configuration features. When you open DevTools in VS Code,
open the top-level devtools/ directory in your VS Code workspace. This will give you access to a set
of launch configurations for running and debugging DevTools:
-
Ensure your local Flutter SDK, DevTools dependencies, and generated code are up-to-date:
dt sync --update-on-path
Warning: this will delete any local changes in your Flutter SDK you checked out from git.
-
Create a branch from your cloned DevTools repo:
git checkout -b myBranch
-
Implement your changes, and commit to your branch:
git commit -m “description”
If your improvement is user-facing, document it in the same PR.
-
Push to your branch to GitHub:
git push origin myBranch
-
Navigate to the Pull Requests tab in the main DevTools repo. You should see a popup to create a pull request from the branch in your cloned repo to the DevTools
masterbranch. Create a pull request.
-
If at any time you need to re-sync your branch, run:
dt syncThis command will:
- pull the latest code from the upstream DevTools master branch
- update
tool/flutter-sdkto the Flutter version DevTools is built and tested with on the CI - upgrade dependencies
- perform code generation
Optionally, pass the
--update-on-pathflag to also update your local Flutter SDK git checkout along with thetool/flutter-sdk. -
If you want to upgrade dependencies and re-generate code (like mocks), but do not want to merge
upstream/masteror update your Flutter SDK version, instead rundt generate-code --upgrade -
To update DCM to the same version as on GitHub bots with apt-get or brew:
-
Locate, copy and run the
apt-getcommand searching by searching for "install dcm" in build.yaml. -
Using the DCM version you just copied in the previous step (without the
-1suffix), installdcmusing homebrew:brew install cqlabs/dcm/dcm@<version on bots without -1>
You can check your local version to verify it matches the version in build.yaml:
dcm --version.If the version of DCM used on the bots is outdated, consider contributing a PR to update the version on the bots to the latest.
-
Please see DEBUGGING.md for guidance on running and debugging DevTools.
Please see TESTING.md for guidance on running and writing tests.
Enabling and activating DCM is optional. When you open a PR, the CI bots will show you any DCM warnings introduced by your change which should be fixed before submitting.
-
Contributors who work at Google: you can use the Google-purchased license key to activate DCM. See go/dash-devexp-dcm-keys.
-
All other contributors: please follow instructions at https://dcm.dev/pricing/. You can either use the free tier of DCM, or purchase a team license. Note that the free tier doesn't support all the rules of the paid tier, so you will also need to consult the output of the Dart Code Metrics workflow on Github when you open your PR.
To enable DCM:
- Install the executable for your target platform. You can refer to this guide.
- Get the license key and activate DCM. To do so, run
dcm activate --license-key=YOUR_KEYfrom the console. - Install the extension for your IDE. If you use VS Code, you can get it from the marketplace. If you use IntelliJ IDEA or Android Studio, you can find the plugin here.
- Reload the IDE.
Note: DCM issues can be distinguished from the Dart analyzer issues by their name: DCM rule names contain dashes
-instead of underscores_. Some of the issues can be fixed via CLI; to do so, rundcm fixfor any directory. To applydcm fixon a file save in the IDE, refer to this guide.
All content not authored by the Flutter team (which includes both sponsored and open-source contributors)
must go in the third_party directory. As an expedient to make the third_party code works well with our
build scripts, code in third_party should be given a stub pubspec.yaml file so that you can reference
the resources from the packages directory from packages/devtools_app/web/index.html.
