Because engines, components shared across the site should be in an in-repo addon called osf-components. Therefore, to generate a component named component-name, you would use the command:
ember g component -ir osf-components component-name
To test all blueprints, use:
yarn test:blueprints
Or, if you just want to run a specific test:
npx mocha ./node-tests/blueprints/handbook-component-test.js