Testing Locally:
asdf plugin test <plugin-name> <plugin-url> [--asdf-tool-version <version>] [--asdf-plugin-gitref <git-ref>] [test-command*]
#
asdf plugin test spectral https://github.com/vbyrd/asdf-spectral.git "spectral --version"
Tests are automatically run in GitHub Actions on push and PR.