stylus/vendor-overwrites/codemirror/addon/lint/stylelint-config.js

window.stylelintDefaultConfig = (defaultSeverity => ({
  // 'sugarss' is a indent-based syntax like Sass or Stylus
  // ref: https://github.com/postcss/postcss#syntaxes
  syntax: 'sugarss',
  // ** recommended rules **
  // ref: https://github.com/stylelint/stylelint-config-recommended/blob/master/index.js
  rules: {
    'at-rule-no-unknown': [true, defaultSeverity],
    'block-no-empty': [true, defaultSeverity],
    'color-no-invalid-hex': [true, defaultSeverity],
    'comment-no-empty': [true, defaultSeverity],
    'declaration-block-no-duplicate-properties': [ true, {
      'ignore': ['consecutive-duplicates-with-different-values'],
      'severity': 'warning'
    }],
    'declaration-block-no-redundant-longhand-properties': [true, defaultSeverity],
    'declaration-block-no-shorthand-property-overrides': [true, defaultSeverity],
    'font-family-no-duplicate-names': [true, defaultSeverity],
    'function-calc-no-unspaced-operator': [true, defaultSeverity],
    'function-linear-gradient-no-nonstandard-direction': [true, defaultSeverity],
    'keyframe-declaration-no-important': [true, defaultSeverity],
    'media-feature-name-no-unknown': [true, defaultSeverity],
    'no-empty-source': false, /* recommended true */
    'no-extra-semicolons': [true, defaultSeverity],
    'no-invalid-double-slash-comments': [true, defaultSeverity],
    'property-no-unknown': [true, defaultSeverity],
    'selector-pseudo-class-no-unknown': [true, defaultSeverity],
    'selector-pseudo-element-no-unknown': [true, defaultSeverity],
    'selector-type-no-unknown': [true, defaultSeverity],
    'shorthand-property-no-redundant-values': [true, defaultSeverity],
    'string-no-newline': [true, defaultSeverity],
    'unit-no-unknown': [true, defaultSeverity]

    // ** stylistic rules **
    /*
    '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-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',
    'comment-empty-line-before': [
      'always',
      {
        'except': [
          'first-nested'
        ],
        'ignore': [
          'stylelint-commands'
        ]
      }
    ],
    '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-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-declaration',
          'first-nested'
        ],
        'ignore': [
          'after-comment',
          'inside-single-line-block'
        ]
      }
    ],
    'function-comma-newline-after': 'always-multi-line',
    'function-comma-space-after': 'always-single-line',
    'function-comma-space-before': 'never',
    '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': 2,
    '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-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-eol-whitespace': true,
    'no-missing-end-of-source-newline': true,
    'number-leading-zero': 'always',
    'number-no-trailing-zeros': true,
    'property-case': 'lower',
    '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-parentheses-space-inside': 'never',
    'selector-pseudo-element-case': 'lower',
    'selector-pseudo-element-colon-notation': 'double',
    'selector-type-case': 'lower',
    'unit-case': 'lower',
    '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
    */
  }
}))({severity: 'warning'});