Stylelint configuration object for Magento 2 Projects based on their coding standards http://devdocs.magento.com/guides/v2.0/coding-standards/code-standard-less.html

.stylelintrc.json

{
  "rules": {
    "indentation": 4,
    "block-opening-brace-space-before": "always",
    "block-opening-brace-newline-after": "always",
    "block-closing-brace-newline-before": "always",
    "selector-list-comma-newline-after": "always",
    "string-quotes": "single",
    "selector-combinator-space-after": "always",
    "selector-combinator-space-before": "always",
    "declaration-block-semicolon-newline-after": "always",
    "declaration-colon-space-after": "always",
    "declaration-colon-space-before": "never",
    "rule-empty-line-before": [ "always", {
      "except": ["first-nested"],
      "ignore": ["after-comment"]
    } ],
    "declaration-block-trailing-semicolon":"always",
    "no-extra-semicolons": true,
    "declaration-block-semicolon-space-before": "never",
    "declaration-no-important": true,
    "comment-empty-line-before": "always",
    "comment-whitespace-inside": "always",
    "comment-no-empty": true,
    "selector-max-id": 0,
    "selector-class-pattern": "^_?[a-z0-9]+(-[a-z0-9]+)*$",
    "selector-type-case": "lower",
    "max-nesting-depth": 3,
    "length-zero-no-unit": true,
    "number-leading-zero": "never",
    "unit-case": "lower",
    "color-hex-case": "lower",
    "color-no-invalid-hex": true,
    "color-hex-length": "short",
    "block-no-empty": true,
    "max-empty-lines": 2,
    "unit-whitelist": ["px", "rem", "%", "s", "fr"]
  }
}