generator-mc-d8-theme/generators/app/templates/stylelintrc.yml

Yeoman generator for creating Drupal 8 component based themes.

# Custom configuration for Stylelint.
#

# Preset all items to warning to prevent breaking themes.
# Delete line to activate linter build-breaking errors.
defaultSeverity: warning

# Plugins integrated.
plugins:
  - stylelint-scss

  # Rules are grouped in 3 categories and then by the context they apply to.
  # - Possible errors
  # - Limit language features
  # - Stylistic issues
rules:

  ### Possible errors
  ## Color.
  # Disallow invalid hex colors.
  # https://stylelint.io/user-guide/rules/color-no-invalid-hex/
  color-no-invalid-hex: true

  ## Font family.
  # Disallow duplicate font family names.
  # https://stylelint.io/user-guide/rules/font-family-no-duplicate-names/
  font-family-no-duplicate-names: true

  # Disallow duplicate font family names.
  # https://stylelint.io/user-guide/rules/font-family-no-duplicate-names/
  font-family-no-missing-generic-family-keyword: true

  ## Function.
  # Disallow an invalid expression within calc functions.
  # https://stylelint.io/user-guide/rules/function-calc-no-invalid/
  function-calc-no-invalid: true

  # Include spaces around operators.
  # https://stylelint.io/user-guide/rules/function-calc-no-unspaced-operator/
  function-calc-no-unspaced-operator: true

  # Prevent invalid linear-gradient syntax.
  # https://stylelint.io/user-guide/rules/function-linear-gradient-no-nonstandard-direction/
  function-linear-gradient-no-nonstandard-direction: true

  ## String.
  # Require escaped new lines in strings.
  # https://stylelint.io/user-guide/rules/string-no-newline/
  string-no-newline: true

  ## Unit.
  # Disallow unknown units.
  # https://stylelint.io/user-guide/rules/unit-no-unknown/
  unit-no-unknown: true

  ## Property.
  # Disallow unknown properties.
  # https://stylelint.io/user-guide/rules/property-no-unknown/
  property-no-unknown: true

  ## Keyframe declaration.
  # Disallow `!important` within keyframe declarations.
  # https://stylelint.io/user-guide/rules/keyframe-declaration-no-important/
  keyframe-declaration-no-important: true

  ## Declaration block.
  # Disallow duplicate properties within declaration blocks.
  # https://stylelint.io/user-guide/rules/declaration-block-no-duplicate-properties/
  declaration-block-no-duplicate-properties:
    - true
    - ignore:
        - consecutive-duplicates-with-different-values

  # Disallow shorthand properties that override related longhand properties.
  # https://stylelint.io/user-guide/rules/declaration-block-no-shorthand-property-overrides/
  declaration-block-no-shorthand-property-overrides: true

  ## Block.
  # Disallow empty blocks.
  # https://stylelint.io/user-guide/rules/block-no-empty/
  block-no-empty: true

  ## Selector.
  # Disallow unknown pseudo-class selectors.
  # https://stylelint.io/user-guide/rules/selector-pseudo-class-no-unknown/
  selector-pseudo-class-no-unknown: true

  # Disallow unknown pseudo-element selectors.
  # https://stylelint.io/user-guide/rules/selector-pseudo-element-no-unknown/
  selector-pseudo-element-no-unknown: true

  # Disallow unknown type selectors.
  # https://stylelint.io/user-guide/rules/selector-type-no-unknown/
  selector-type-no-unknown: true

  ## Media feature
  # Disallow unknown media feature names.
  # https://stylelint.io/user-guide/rules/media-feature-name-no-unknown/
  media-feature-name-no-unknown: true

  ## At-rule
  # Disallow unknown at-rules.
  # https://stylelint.io/user-guide/rules/at-rule-no-unknown/
  #at-rule-no-unknown:
  #  - true
  #  - ignoreAtRules:
  #      - 'include'

  ## Comment
  # Disallow empty comments.
  # https://stylelint.io/user-guide/rules/comment-no-empty/
  comment-no-empty: true

  ## General / Sheet
  # Disallow duplicate @import rules within a stylesheet.
  # https://stylelint.io/user-guide/rules/no-duplicate-at-import-rules/
  no-duplicate-at-import-rules: true

  # Disallow duplicate selectors.
  # https://stylelint.io/user-guide/rules/no-duplicate-selectors/
  no-duplicate-selectors: true

  # Disallow empty sources.
  # https://stylelint.io/user-guide/rules/no-empty-source/
  # Rule canceled out due to lack of understanding.
  no-empty-source: null
  # Disallow extra semicolons.
  # https://stylelint.io/user-guide/rules/no-extra-semicolons/
  no-extra-semicolons: true

  # Disallow double-slash comments in css (not scss)
  # This issue only affects *.css files.
  # https://stylelint.io/user-guide/rules/no-invalid-double-slash-comments/
  no-invalid-double-slash-comments: true

  # -----------------------

  ### Limit language features
  ## Color
  # Disallow named colors.
  # https://stylelint.io/user-guide/rules/color-named/
  color-named:
    - never
    - ignore:
        - inside-function

  ## Shorthand property
  # Disallow redundant values in shorthand properties.
  # https://github.com/stylelint/stylelint/blob/master/lib/rules/shorthand-property-no-redundant-values/README.md
  shorthand-property-no-redundant-values: true

  ## Value
  # Disallow vendor prefixes for values.
  # https://stylelint.io/user-guide/rules/value-no-vendor-prefix/
  value-no-vendor-prefix: true

  ## Property
  # Disallow vendor prefixes for properties.
  # https://stylelint.io/user-guide/rules/property-no-vendor-prefix/
  property-no-vendor-prefix: true

  ## Declaration
  # Disallow !important within declarations.
  # https://stylelint.io/user-guide/rules/declaration-no-important/
  declaration-no-important: true

  # Specify a blacklist of disallowed property and value pairs within declarations.
  # https://stylelint.io/user-guide/rules/declaration-property-value-blacklist/
  declaration-property-value-disallowed-list:
    # Prefer the terser border: 0 over border: none.
    //bborder\b/:
      - none

  ## Selector
  # Limit the number of adjacent empty lines within selectors.
  # https://stylelint.io/user-guide/rules/selector-max-empty-lines/
  selector-max-empty-lines: 0

  # Disallow qualifying a selector by type.
  # https://stylelint.io/user-guide/rules/selector-no-qualifying-type/
  selector-no-qualifying-type:
    - true
    - ignore:
        - attribute

  # -----------------------

  ### Stylistic issues

  # Specify indentation.
  # https://stylelint.io/user-guide/rules/indentation/
  indentation: 2

  ## Color
  # Specify lowercase or uppercase for hex colors.
  # https://stylelint.io/user-guide/rules/color-hex-case/
  color-hex-case: lower

  ## Function
  # Require a single space after the commas of functions.
  # https://stylelint.io/user-guide/rules/function-comma-space-after/
  function-comma-space-after: always

  # Disallow whitespace before the commas of functions.
  # https://stylelint.io/user-guide/rules/function-comma-space-before/
  function-comma-space-before: never

  # Specify lowercase for function names.
  # https://stylelint.io/user-guide/rules/function-name-case/
  function-name-case: lower

  # Disallow whitespace on the inside of the parentheses of functions.
  # https://stylelint.io/user-guide/rules/function-parentheses-space-inside/
  function-parentheses-space-inside: never

  # Require quotes for urls.
  # https://stylelint.io/user-guide/rules/function-url-quotes/
  function-url-quotes: always

  # Require whitespace after functions.
  # https://stylelint.io/user-guide/rules/function-whitespace-after/
  function-whitespace-after: always

  ## Number
  # Require a leading zero for fractional numbers less than 1.
  # https://stylelint.io/user-guide/rules/number-leading-zero/
  number-leading-zero: always

  # Disallow trailing zeros in numbers
  # https://stylelint.io/user-guide/rules/number-no-trailing-zeros/
  number-no-trailing-zeros: true

  ## String
  # Prefer single quotes.
  # https://stylelint.io/user-guide/rules/string-quotes/
  string-quotes: single

  ## Length
  # Disallow units for zero lengths.
  # https://stylelint.io/user-guide/rules/length-zero-no-unit/
  length-zero-no-unit: true

  ## Unit
  # Specify lowercase or uppercase for units.
  # https://stylelint.io/user-guide/rules/unit-case/
  unit-case: lower

  ## Value
  # Specify lowercase for keywords values.
  # https://stylelint.io/user-guide/rules/value-keyword-case/
  value-keyword-case: lower

  ## Value list
  # Require a newline after the commas of value lists.
  # https://stylelint.io/user-guide/rules/value-list-comma-newline-after/
  value-list-comma-newline-after: always-multi-line

  # Disallow whitespace before the commas in multi-line value lists.
  # https://stylelint.io/user-guide/rules/value-list-comma-newline-before/
  value-list-comma-newline-before: never-multi-line

  # Require a single space after the commas of value lists.
  # https://stylelint.io/user-guide/rules/value-list-comma-space-after/
  value-list-comma-space-after: always-single-line

  # Disallow whitespace before the commas of value lists.
  # https://stylelint.io/user-guide/rules/value-list-comma-space-before/
  value-list-comma-space-before: never

  # Limit the number of adjacent empty lines within value lists.
  # https://stylelint.io/user-guide/rules/value-list-max-empty-lines/
  value-list-max-empty-lines: 0

  ## Property
  # Specify lowercase for properties.
  # https://stylelint.io/user-guide/rules/property-case/
  property-case: lower

  ## Declaration
  # Never allow whitespace after the bang of declarations.
  # https://stylelint.io/user-guide/rules/declaration-bang-space-after/
  declaration-bang-space-after: never

  # Require a single spacebefore the bang of declarations.
  # https://stylelint.io/user-guide/rules/declaration-bang-space-before/
  declaration-bang-space-before: always

  # Require a newline after the colon, when the values are multi-line, of declarations.
  # https://stylelint.io/user-guide/rules/declaration-colon-newline-after/
  declaration-colon-newline-after: always-multi-line

  # Require a single space after the colon of declarations.
  # https://stylelint.io/user-guide/rules/declaration-colon-space-after/
  declaration-colon-space-after: always-single-line

  # Never allow whitespace before the colon of declarations.
  # https://stylelint.io/user-guide/rules/declaration-colon-space-before/
  declaration-colon-space-before: never

  # Never have empty lines before declarations in a block.
  # https://stylelint.io/user-guide/rules/declaration-empty-line-before/
  declaration-empty-line-before: never

  ## Declaration Block
  # Always have a new line after a ;.
  # https://stylelint.io/user-guide/rules/declaration-block-semicolon-newline-after/
  declaration-block-semicolon-newline-after: always

  # Never include a new line before a ;.
  # https://stylelint.io/user-guide/rules/declaration-block-semicolon-newline-before/
  declaration-block-semicolon-newline-before: never-multi-line

  # Never allow a space after the ; when on a single line.
  # https://stylelint.io/user-guide/rules/declaration-block-semicolon-space-after/
  declaration-block-semicolon-space-after: never-single-line

  # Never allow a space before the ;.
  # https://stylelint.io/user-guide/rules/declaration-block-semicolon-space-before/
  declaration-block-semicolon-space-before: never

  # Always include a trailing ; in a declaration block.
  # https://stylelint.io/user-guide/rules/declaration-block-trailing-semicolon/
  declaration-block-trailing-semicolon: always

  ## Block.
  ### These are typically managed by Prettier.
  # Do not include an empty line before the closing brace of a block.
  # https://stylelint.io/user-guide/rules/block-closing-brace-empty-line-before/
  block-closing-brace-empty-line-before: never

  # Always incluse a new line after a block's closing brace.
  # https://stylelint.io/user-guide/rules/block-closing-brace-newline-after/
  block-closing-brace-newline-after: always

  # Require a new line before the closing brace of a block.
  # https://stylelint.io/user-guide/rules/block-closing-brace-newline-before/
  block-closing-brace-newline-before: always

  # To ensure consistency with single/multi line blocks, enforce a new line after the opening brace of a block.
  # https://stylelint.io/user-guide/rules/block-opening-brace-newline-after/
  block-opening-brace-newline-after: always

  ## Selector
  # Disallow whitespace on the inside of the brackets within attribute selectors.
  # https://stylelint.io/user-guide/rules/selector-attribute-brackets-space-inside/
  selector-attribute-brackets-space-inside: never

  # Disallow whitespace after operators within attribute selectors.
  # https://stylelint.io/user-guide/rules/selector-attribute-operator-space-after/
  selector-attribute-operator-space-after: never

  # Disallow whitespace before operators within attribute selectors.
  # https://stylelint.io/user-guide/rules/selector-attribute-operator-space-before/
  selector-attribute-operator-space-before: never

  # Require quotes for attribute values.
  # https://stylelint.io/user-guide/rules/selector-attribute-quotes/
  selector-attribute-quotes: always

  # Require a single space or disallow whitespace after the combinators of selectors.
  # https://stylelint.io/user-guide/rules/selector-combinator-space-after/
  selector-combinator-space-after: always

  # Require a single space before the combinators of selectors.
  # https://stylelint.io/user-guide/rules/selector-combinator-space-before/
  selector-combinator-space-before: always

  # Disallow non-space characters for descendant combinators of selectors.
  # https://stylelint.io/user-guide/rules/selector-descendant-combinator-no-non-space/
  selector-descendant-combinator-no-non-space: true

  # Specify lowercase for pseudo-class selectors.
  # https://stylelint.io/user-guide/rules/selector-pseudo-class-case/
  selector-pseudo-class-case: lower

  # Disallow whitespace on the inside of the parentheses within pseudo-class selectors.
  # https://stylelint.io/user-guide/rules/selector-pseudo-class-parentheses-space-inside/
  selector-pseudo-class-parentheses-space-inside: never

  # Specify lowercase for pseudo-element selectors.
  # https://stylelint.io/user-guide/rules/selector-pseudo-element-case/
  selector-pseudo-element-case: lower

  # Specify double colon notation for applicable pseudo-elements.
  # https://stylelint.io/user-guide/rules/selector-pseudo-element-colon-notation/
  selector-pseudo-element-colon-notation: double

  # Specify lowercase for type selectors.
  # https://stylelint.io/user-guide/rules/selector-type-case/
  selector-type-case: lower

  ## Selector List
  # Require a newline after the commas of selector lists.
  # https://stylelint.io/user-guide/rules/selector-list-comma-newline-after/
  selector-list-comma-newline-after: always

  # Disallow whitespace before the commas of selector lists.
  # https://stylelint.io/user-guide/rules/selector-list-comma-space-before/
  selector-list-comma-space-before: never

  ## Rule
  # Require empty lines before rules.
  # https://stylelint.io/user-guide/rules/rule-empty-line-before/
  # Note that `rule-non-nested-empty-line-before` is Deprecated per https://github.com/18F/stylelint-rules/issues/26
  rule-empty-line-before:
    - always
    - ignore:
        - after-comment

  # Prefer newline at the end of a file.
  # https://stylelint.io/user-guide/rules/no-missing-end-of-source-newline/
  no-missing-end-of-source-newline: true