5.4 just fmt and just lint

Read the tutorial. Build it yourself is the other way to read this part.

This walk goes through rahuldave/cheesecracker on GitHub. This part starts from the code at 7c1670fd52a0, partway through step-05. The code before this part

To look at this code on your machine, run these commands. The first one makes a clone, if this folder has none:

[ -d cheesecracker ] || git clone https://github.com/rahuldave/cheesecracker
cd cheesecracker
git fetch --quiet --tags --force origin
git switch --detach 7c1670fd52a0

just setup

The whole tutorial then makes a change in a hurry. It adds ruff, one tool that does two jobs. As a formatter, it lays out the code in one fixed way. As a linter, it checks the code against rules. The tutorial gives ruff the rules of flake8, an older linter. The formatter and the linter get a recipe each.

just fmt --check

@@ -44,3 +44,11 @@ stop:
 # Run the tests, and show which lines of the package api they ran. Extra arguments go to pytest: just cov tests/unit
 cov *args:
     uv run pytest --cov=api --cov-report=term-missing "$@"
+
+# Format the code, one way. Extra arguments go to ruff: just fmt --check, just fmt --diff
+fmt *args:
+    uv run ruff format "$@"
+
+# Check the code against the rules in pyproject.toml. Extra arguments go to ruff: just lint --fix
+lint *args:
+    uv run ruff check "$@"