6.9. Linting

Composer will install squizlabs/php_codesniffer package by default, which will install phpcs.

Run:

./vendor/bin/phpcs --standard=PSR12 \
    includes/ \
    public/*.php \
    tests/api/ \
    tests/runner_generate_db.php

Ensure that all code passes linting tests, because the CI will fail any pull request or merge that fails the linting.