For learning styleguide development.
# Install nodejs tools.
$ yarn
# Install Gulp CLI.
$ npm i -g gulp-cli
# or
$ yarn global add gulp-cli
# Install Pattern Lab.
$ composer install
$ gulp
Using BackstopJS.
# Generate reference images.
$ gulp visual-regression:ref
# Start test.
$ gulp visual-regression:test
# You can use filter option.
$ gulp visual-regression:test --filter <scenario.label>
# Approving test results.
$ gulp visual-regression:approve