Write and reason about tests, covering behavior, edge cases, and errors.
$npx -y skills add byronxlg/skillfold --skill testingInstalls into the current project.
Run `npx skills use "https://github.com/byronxlg/skillfold" --skill "byronxlg/skillfold/testing"` and follow the generated skill instructions now. Read its complete output, redirecting it to a temporary file first if necessary. Resolve relative paths from the supporting-files directory it provides.
Use the skills in "https://github.com/byronxlg/skillfold" that are relevant to the current task. Run `npx skills add "https://github.com/byronxlg/skillfold"` and select the relevant skills, then follow their instructions.