stylelint.config.js

module.exports = {
  plugins: [
    'stylelint-scss',
  ],
  rules: {
    'linebreaks': 'unix',
    'max-line-length': 160,
    'indentation': 2,
    'max-nesting-depth': 5,
    'selector-max-universal': 1,
    'selector-max-id': 0,
    'selector-max-class': 1,
    'selector-max-type': 2,
    'selector-max-attribute': 1,
    'selector-max-pseudo-class': 2,
    'selector-max-compound-selectors': 1,
    'selector-no-vendor-prefix': true,

    'scss/dollar-variable-pattern': '[a-z]+(-[a-z]+)*',
    'scss/at-extend-no-missing-placeholder': true,

    'declaration-property-value-blacklist': {
      '/^border/': ['none'],
    },

    'selector-pseudo-element-colon-notation': 'double',
    'color-hex-length': 'long',
    'declaration-block-semicolon-newline-after': 'always',
    'value-no-vendor-prefix': true,
    'declaration-no-important': true,


    /* *********** */
    /* FROM TYPO3: */
    /* *********** */
    /* *********** */

    'at-rule-empty-line-before': [
      'always',
      {
        'except': [
          'blockless-after-same-name-blockless',
          'first-nested',
        ],
        'ignore': [
          'after-comment',
        ],
      },
    ],
    'at-rule-name-case': 'lower',
    'at-rule-name-space-after': 'always-single-line',
    'at-rule-semicolon-newline-after': 'always',
    'block-closing-brace-empty-line-before': 'never',
    'block-closing-brace-newline-after': 'always',
    'block-closing-brace-newline-before': 'always-multi-line',
    'block-closing-brace-space-before': 'always-single-line',
    'block-no-empty': true,
    'block-opening-brace-newline-after': 'always-multi-line',
    'block-opening-brace-space-after': 'always-single-line',
    'block-opening-brace-space-before': 'always',
    'color-hex-case': 'lower',
    // 'color-hex-length': 'short',
    'color-no-invalid-hex': true,
    'comment-empty-line-before': [
      'always',
      {
        'except': [
          'first-nested',
        ],
        'ignore': [
          'stylelint-commands',
        ],
      },
    ],
    'comment-no-empty': true,
    'comment-whitespace-inside': 'always',
    'custom-property-empty-line-before': [
      'always',
      {
        'except': [
          'after-custom-property',
          'first-nested',
        ],
        'ignore': [
          'after-comment',
          'inside-single-line-block',
        ],
      },
    ],
    'declaration-bang-space-after': 'never',
    'declaration-bang-space-before': 'always',
    'declaration-block-no-duplicate-properties': [
      true,
      {
        'ignore': [
          'consecutive-duplicates-with-different-values',
        ],
      },
    ],
    'declaration-block-no-redundant-longhand-properties': true,
    'declaration-block-no-shorthand-property-overrides': true,
    // 'declaration-block-semicolon-newline-after': 'always-multi-line',
    'declaration-block-semicolon-space-after': 'always-single-line',
    'declaration-block-semicolon-space-before': 'never',
    'declaration-block-single-line-max-declarations': 1,
    'declaration-block-trailing-semicolon': 'always',
    'declaration-colon-newline-after': 'always-multi-line',
    'declaration-colon-space-after': 'always-single-line',
    'declaration-colon-space-before': 'never',
    'declaration-empty-line-before': [
      'always',
      {
        'except': [
          'after-comment',
          'after-declaration',
          'first-nested',
        ],
        'ignore': [
          'inside-single-line-block',
        ],
      },
    ],
    'font-family-no-duplicate-names': true,
    'function-calc-no-unspaced-operator': true,
    'function-comma-newline-after': 'always-multi-line',
    'function-comma-space-after': 'always-single-line',
    'function-comma-space-before': 'never',
    'function-linear-gradient-no-nonstandard-direction': true,
    'function-max-empty-lines': 0,
    'function-name-case': 'lower',
    'function-parentheses-newline-inside': 'always-multi-line',
    'function-parentheses-space-inside': 'never-single-line',
    'function-whitespace-after': 'always',
    // 'indentation': 4,
    'keyframe-declaration-no-important': true,
    'length-zero-no-unit': true,
    'max-empty-lines': 1,
    'media-feature-colon-space-after': 'always',
    'media-feature-colon-space-before': 'never',
    'media-feature-name-case': 'lower',
    'media-feature-name-no-unknown': true,
    'media-feature-parentheses-space-inside': 'never',
    'media-feature-range-operator-space-after': 'always',
    'media-feature-range-operator-space-before': 'always',
    'media-query-list-comma-newline-after': 'always-multi-line',
    'media-query-list-comma-space-after': 'always-single-line',
    'media-query-list-comma-space-before': 'never',
    'no-empty-source': true,
    'no-eol-whitespace': true,
    'no-extra-semicolons': true,
    'no-invalid-double-slash-comments': true,
    'no-missing-end-of-source-newline': true,
    'number-leading-zero': 'always',
    'number-no-trailing-zeros': true,
    'property-case': 'lower',
    'property-no-unknown': true,
    // 'rule-empty-line-before': [
    //   'always-multi-line',
    //   {
    //     'except': [
    //       'first-nested'
    //     ],
    //     'ignore': [
    //       'after-comment'
    //     ]
    //   }
    // ],
    'selector-attribute-brackets-space-inside': 'never',
    'selector-attribute-operator-space-after': 'never',
    'selector-attribute-operator-space-before': 'never',
    'selector-combinator-space-after': 'always',
    'selector-combinator-space-before': 'always',
    'selector-descendant-combinator-no-non-space': true,
    'selector-list-comma-newline-after': 'always',
    'selector-list-comma-space-before': 'never',
    'selector-max-empty-lines': 0,
    'selector-pseudo-class-case': 'lower',
    'selector-pseudo-class-no-unknown': true,
    'selector-pseudo-class-parentheses-space-inside': 'never',
    'selector-pseudo-element-case': 'lower',
    // 'selector-pseudo-element-colon-notation': 'single',
    'selector-pseudo-element-no-unknown': true,
    'selector-type-case': 'lower',
    'selector-type-no-unknown': true,
    'shorthand-property-no-redundant-values': true,
    'string-no-newline': true,
    'unit-case': 'lower',
    'unit-no-unknown': true,
    'value-list-comma-newline-after': 'always-multi-line',
    'value-list-comma-space-after': 'always-single-line',
    'value-list-comma-space-before': 'never',
    'value-list-max-empty-lines': 0,
  },
};