stylelint
A linter that helps you avoid errors and enforce conventions
stylelint understands the latest CSS syntax including custom properties and level 4 selectors. Extracts embedded styles from HTML, markdown and CSS-in-JS object & template literals. Parses CSS-like syntaxes like SCSS, Sass, Less and SugarSS. Has over 170 built-in rules to catch errors, apply limits and enforce stylistic conventions. Supports plugins so you can create your own rules or make use of plugins written by the community.