.stylelintrc

---
extends:
  - stylelint-config-standard
  - stylelint-config-recommended-scss
plugins:
  - stylelint-order
rules:
  # Disallow @debug
  # https://stylelint.io/user-guide/rules/at-rule-disallowed-list
  at-rule-disallowed-list:
  - debug

  # This rule is disabled because our house style has a lot of at-rules
  # via SCSS where new lines are used indiscriminately for readability.
  # https://stylelint.io/user-guide/rules/at-rule-empty-line-before
  at-rule-empty-line-before: null

  # This is disabled for SCSS as it prevents SCSS specific @ rules (such as @if)
  # https://stylelint.io/user-guide/rules/at-rule-no-unknown
  at-rule-no-unknown: null

  # Unknown rule
  # Always require a newline after a closing brace of a rule
  # https://stylelint.io/user-guide/rules/block-closing-brace-newline-after
  # block-closing-brace-newline-after:
  # - always
  #   # Exceptions for conditionals, particularly useful for SCSS.
  # - ignoreAtRules:
  #   - if
  #   - else

  # Disallow using CSS named colours
  # https://stylelint.io/user-guide/rules/color-named
  color-named: never

  # Require 6 character hex definitions when 3 would work
  # https://stylelint.io/user-guide/rules/color-hex-length
  color-hex-length: long

  # Require all rules to be multiline
  # https://stylelint.io/user-guide/rules/declaration-block-single-line-max-declarations
  declaration-block-single-line-max-declarations: 0

  # Its common for us to break up groups of CSS with an empty line
  # https://stylelint.io/user-guide/rules/declaration-empty-line-before
  declaration-empty-line-before: null

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

  # Properties and values that are disallowed
  # https://stylelint.io/user-guide/rules/declaration-property-value-disallowed-list
  declaration-property-value-disallowed-list:
    /transition/:
    - /all/

  # Disallow unknown functions
  # https://stylelint.io/user-guide/rules/list/function-no-unknown/
  function-no-unknown: null

  # Disallow scheme relative URLs such as //www.simonwhatley.co.uk
  # https://stylelint.io/user-guide/rules/function-url-no-scheme-relative
  function-url-no-scheme-relative: true

  # Always require quotes in url function calls
  # https://stylelint.io/user-guide/rules/function-url-quotes
  function-url-quotes: always

  # Disallow absolute URLs with scheme other than data, assets should be local
  # https://stylelint.io/user-guide/rules/function-url-scheme-allowed-list
  function-url-scheme-allowed-list:
  - data

  # Specify string or URL notation for @import rules.
  # https://stylelint.io/user-guide/rules/import-notation
  import-notation: string

  # Disallow deep nesting, ideally only exceptions (such as .js-enabled) should
  # have nesting
  # https://stylelint.io/user-guide/rules/max-nesting-depth
  max-nesting-depth:
  - 2
  - ignore:
    - blockless-at-rules
    - pseudo-classes

  # This rules attempts to prevent defining defining rules with a more
  # specific selector than a previous one, where they may override. This
  # is disables as it conflicts with our common usage of nesting rules
  # within a BEM modifier where a selector may be more or less specific
  # than a previous rule.
  # https://stylelint.io/user-guide/rules/no-descending-specificity
  no-descending-specificity: null

  # Unknown rule
  # Disallow prefixing decimals with a 0
  # https://stylelint.io/user-guide/rules/number-leading-zero
  # number-leading-zero: never

  # Require all class selectors to be in a hyphenated BEM format
  # https://stylelint.io/user-guide/rules/selector-class-pattern
  selector-class-pattern:
  # a loose interpretation on hyphenathed BEM in order to allow BEM
  # style and govuk-! overrides
  - ^[a-z]([a-z0-9-_!])*$
  - resolveNestedSelectors: true
    message: >-
      Class names may only contain [a-z0-9-_!] characters and must start with [a-z]

  # Require any allowed id selectors to be in a hyphenated lowercase form
  # https://stylelint.io/user-guide/rules/selector-id-pattern
  selector-id-pattern:
  - ^[a-z]([a-z0-9-])*$
  - resolveNestedSelectors: true
    message: >-
      Ids may only contain [a-z0-9-] characters and must start with [a-z]

  # Disallow all ids in selectors
  # https://stylelint.io/user-guide/rules/selector-max-id
  selector-max-id: 0

  # Disallows qualifying a selector based on the element
  # https://stylelint.io/user-guide/rules/selector-no-qualifying-type
  selector-no-qualifying-type:
  - true
    # allowed for input[type=button] and similar
  - ignore:
    - attribute

  # Require single colons for defining pseudo-elements
  # IE8 and below do not support the modern double colon approach. Although
  # few projects support IE8, wed prefer to not exclude compatibility for
  # purely syntactic reasons.
  # https://stylelint.io/user-guide/rules/selector-pseudo-element-colon-notation
  selector-pseudo-element-colon-notation: single

  # Disallow redundant properties in rules (for example: margin: 1px 1px 1px;)
  # https://stylelint.io/user-guide/rules/shorthand-property-no-redundant-values
  shorthand-property-no-redundant-values: true

  # Require a new line after a @else { } statement
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-else-closing-brace-newline-after
  scss/at-else-closing-brace-newline-after: always-last-in-chain

  # Require a space after an @else {} before the next @else rule
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-else-closing-brace-space-after
  scss/at-else-closing-brace-space-after: always-intermediate

  # Disallow empty lines before an @else statement
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-else-empty-line-before
  scss/at-else-empty-line-before: never

  # Only allow @extend with a placeholder
  # https://github.com/kristerkari/stylelint-scss/blob/master/src/rules/at-extend-no-missing-placeholder
  scss/at-extend-no-missing-placeholder: true

  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-function-pattern
  scss/at-function-pattern:
  - ^_?([a-z0-9-])*$
  - message: >-
      Function names may only contain [a-z0-9-] characters and may start with an underscore

  # Require a new line character at the termination of a group of @if / @else
  # definitions
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-if-closing-brace-newline-after
  scss/at-if-closing-brace-newline-after: always-last-in-chain

  # Require a space between an @if {} ending and an @else beginning
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-if-closing-brace-space-after
  scss/at-if-closing-brace-space-after: always-intermediate

  # Disallow importing partials with a underscore prefix
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-import-no-partial-leading-underscore
  scss/at-import-no-partial-leading-underscore: true

  # Disallow importing partials with a underscore prefix
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-import-partial-extension
  scss/at-import-partial-extension: never

  # Disallow parenthesis when including a mixin with no parameters
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-mixin-argumentless-call-parentheses
  scss/at-mixin-argumentless-call-parentheses: never

  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-mixin-pattern
  scss/at-mixin-pattern:
  - ^_?([a-z0-9-])*$
  - message: >-
      Mixin names may only contain [a-z0-9-] characters and may start with an underscore

  # This lints that only @ rules known to SCSS are allowed
  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/at-rule-no-unknown
  scss/at-rule-no-unknown: true

  # Disable CSS style comments in SCSS
  # https://github.com/kristerkari/stylelint-scss/blob/master/src/rules/comment-no-loud
  scss/comment-no-loud: true

  # https://github.com/kristerkari/stylelint-scss/tree/master/src/rules/dollar-variable-pattern
  scss/dollar-variable-pattern:
  - ^_?([a-z0-9-])*$
  - message: >-
      Variable names may only contain [a-z0-9-] characters and may start with an underscore

  # Require spaces around operators
  # https://github.com/kristerkari/stylelint-scss/blob/master/src/rules/operator-no-unspaced
  scss/operator-no-unspaced: true

  # https://github.com/kristerkari/stylelint-scss/blob/master/src/rules/percent-placeholder-pattern
  scss/percent-placeholder-pattern:
  - ^[a-z0-9-_]*$
  - message: >-
      Placeholders may only contain [a-z0-9-_] characters

  # https://github.com/hudochenkov/stylelint-order/blob/master/rules/properties-order/README.md
  order/properties-order:
  - content
  - quotes
  # Box-sizing - Allow here until global is decided
  - box-sizing

  - display
  - visibility

  - position
  - z-index
  - top
  - right
  - bottom
  - left

  - width
  - min-width
  - max-width
  - height
  - min-height
  - max-height

  - margin
  - margin-top
  - margin-right
  - margin-bottom
  - margin-left

  - padding
  - padding-top
  - padding-right
  - padding-bottom
  - padding-left

  - float
  - clear

  - overflow
  - overflow-x
  - overflow-y

  - clip
  - clip-path
  - zoom
  - resize

  - columns

  - table-layout
  - empty-cells
  - caption-side
  - border-spacing
  - border-collapse

  - list-style
  - list-style-position
  - list-style-type
  - list-style-image

  - transform
  - transition
  - animation

  - border
  - border-top
  - border-right
  - border-bottom
  - border-left

  - border-width
  - border-top-width
  - border-right-width
  - border-bottom-width
  - border-left-width

  - border-style
  - border-top-style
  - border-right-style
  - border-bottom-style
  - border-left-style

  - border-radius
  - border-top-left-radius
  - border-top-right-radius
  - border-bottom-left-radius
  - border-bottom-right-radius

  - border-color
  - border-top-color
  - border-right-color
  - border-bottom-color
  - border-left-color

  - outline
  - outline-color
  - outline-offset
  - outline-style
  - outline-width

  - opacity
  # Color has been moved to ensure it appears before background
  - color
  - background
  - background-color
  - background-image
  - background-repeat
  - background-position
  - background-size
  - box-shadow
  - fill

  - font
  - font-family
  - font-size
  - font-style
  - font-variant
  - font-weight

  - font-emphasize

  - letter-spacing
  - line-height
  - list-style
  - word-spacing

  - text-align
  - text-align-last
  - text-decoration
  - text-indent
  - text-justify
  - text-overflow
  - text-overflow-ellipsis
  - text-overflow-mode
  - text-rendering
  - text-outline
  - text-shadow
  - text-transform
  - text-wrap
  - word-wrap
  - word-break

  - text-emphasis

  - vertical-align
  - white-space
  - word-spacing
  - hyphens

  - src
  - cursor
  - -webkit-appearance