Developing and Documenting Locust
You want to contribute to Locust? Great! Here is a list of open bugs/feature requests.
Install Locust for development
Fork Locust on GitHub and then
# clone the repo:
$ git clone git://github.com/<YourName>/locust.git
# install the poetry build system, see https://python-poetry.org/docs/#installation
# install the required poetry plugins:
$ poetry self add "poethepoet[poetry_plugin]"
$ poetry self add "poetry-dynamic-versioning[plugin]"
# perform an editable install of the "locust" package along with the dev and test packages:
$ poetry install --with dev,test
Now the poetry run locust
command will run your code (with no need for reinstalling after making changes).
To contribute your changes, push to a branch in your repo and then open a PR on github.
If you install pre-commit, linting and format checks/fixes will be automatically performed before each commit.
Before you open a pull request, make sure all the tests work. And if you are adding a feature, make sure it is documented (in docs/*.rst
).
If you’re in a hurry or don’t have access to a development environment, you can simply use Codespaces, the github cloud development environment. On your fork page, just click on Code then on Create codespace on <branch name>, and voila, your ready to code and test.
Testing your changes
We use tox to automate tests across multiple Python versions:
$ tox
...
py39: commands[1]> python3 -m unittest discover
...
To only run a specific suite or specific test you can call pytest directly:
$ pytest locust/test/test_main.py::DistributedIntegrationTests::test_distributed_tags
Debugging
Formatting and linting
Locust uses ruff for formatting and linting. The build will fail if code does not adhere to it. If you run vscode it will automatically run every time you save a file, but if your editor doesn’t support it you can run it manually:
$ ruff --fix <file_or_folder_to_be_formatted>
$ ruff format <file_or_folder_to_be_formatted>
You can validate the whole project using tox:
$ tox -e ruff
ruff: install_deps> python -I -m pip install ruff==0.1.13
ruff: commands[0]> ruff check .
ruff: commands[1]> ruff format --check
104 files already formatted
ruff: OK (1.41=setup[1.39]+cmd[0.01,0.01] seconds)
congratulations :) (1.47 seconds)
Build documentation
The documentation source is in the docs/ directory. To build the documentation you’ll need to Install Locust for development then
Install the documentation requirements:
$ poetry install --with docs
Build the documentation locally:
$ make build_docs
View your generated documentation by opening docs/_build/index.html
.
Making changes to Locust’s Web UI
The Web UI is built using React and Typescript
Setup
Node
Install node using nvm to easily switch between node version
Copy and run the install line from nvm (starts with curl/wget …)
Verify nvm was installed correctly
$ nvm --version
Install the proper Node version according to engines in the
locust/webui/package.json
$ nvm install {version}
$ nvm alias default {version}
Yarn
Install Yarn from their official website (avoid installing through Node if possible)
Verify yarn was installed correctly
$ yarn --version
Next, install all dependencies
$ cd locust/webui
$ yarn
Developing
To develop while running a locust instance, run yarn watch
. This will output the static files to the dist
directory. Vite will automatically detect any changed files and re-build as needed. Simply refresh the page to view the changes
In certain situations (usually when styling), you may want to develop the frontend without running a locust instance. Running yarn dev
will start the Vite dev server and allow for viewing your changes.
To compile the webui, run yarn build
The frontend can additionally be built using make:
$ make frontend_build
Linting
Run yarn lint
to detect lint failures in the frontend project. Running yarn lint --fix
will resolve any issues that are automatically resolvable. Your IDE can additionally be configured with ESLint to resolve these issues on save.
Formatting
Run yarn format
to fix any formatting issues in the frontend project. Once again your IDE can be configured to automatically format on save.
Typechecking
We use Typescript in the frontend project. Run yarn type-check
to find any issues.