Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

Hex Notation

Rule hex-notation will enforce the case of hexadecimal values

Options

• style: lowercase/uppercase (defaults to lowercase)

Examples

When style: lowercase, the following are allowed. When style: uppercase, the following are disallowed:

$foo-color: #fff;

.bar {
  background: linear-gradient(top, #cc2, #44d);
}

.baz {
  color: #12a;
}

When style: uppercase, the following are allowed. When style: lowercase, the following are disallowed:

$foo-color: #FFF;

.bar {
  background: linear-gradient(top, #CC2, #44D);
}

.baz {
  color: #12A;
}

In both cases the following will be allowed as the values contain only numbers:

.qux {
  color: #123;
}

Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

Space Before Colon

Rule space-before-colon will enforce whether or not a space should be included before a colon (:).

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  content: 'bar';
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  content :'bar';
}

For more information visit Source: http://eslint.org/docs/rules/

For more information visit Source: http://eslint.org/docs/rules/

Property Sort Order

Rule property-sort-order will enforce the order in which declarations are written.

Options

• order: 'alphabetical', 'concentric', 'recess', 'smacss', or [array of properties] (defaults to alphabetical. Unknown properties are sorted alphabetically)
• ignore-custom-properties: true/false (defaults to false)

Property orders: https://github.com/sasstools/sass-lint/tree/develop/lib/config/property-sort-orders

Examples

When enabled (assuming order: alphabetical), the following are allowed:

.foo {
  content: 'baz';
  height: 100vh;
  width: 100vw;
}

When enabled (assuming order: alphabetical), the following are disallowed:

.foo {
  width: 100vw;
  height: 100vh;
  content: 'baz';
}

Custom Sort Orders

You have the option to create your own custom property sort orders. These are specified in your .sass-lint.yml file as below:

property-sort-order:
  - 1
  -
    order:
      - border
      - display
      - color

When the custom order is specified as above, the following are allowed:

.foo {
  border: 1px solid blue;
  display: block;
  color: red;
}

When the custom order is specified as above, the following are disallowed:

.foo {
  display: block;
  color: red;
  border: 1px solid blue;
}

Ignore Custom Properties

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be allowed

.foo {
  border: 1px solid blue;
  color: red;
  composes: heading;
  display: block;
}

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be disallowed

.foo {
  composes: heading; // not in alphabetical order
  border: 1px solid blue;
  color: red;
  display: block;
}

When ignore-custom-properties: true (assume order: 'alphabetical') the following would be allowed

.foo {
  composes: heading; // custom properties ignored
  border: 1px solid blue;
  color: red;
  display: block;
}

Property Sort Order

Rule property-sort-order will enforce the order in which declarations are written.

Options

• order: 'alphabetical', 'concentric', 'recess', 'smacss', or [array of properties] (defaults to alphabetical. Unknown properties are sorted alphabetically)
• ignore-custom-properties: true/false (defaults to false)

Property orders: https://github.com/sasstools/sass-lint/tree/develop/lib/config/property-sort-orders

Examples

When enabled (assuming order: alphabetical), the following are allowed:

.foo {
  content: 'baz';
  height: 100vh;
  width: 100vw;
}

When enabled (assuming order: alphabetical), the following are disallowed:

.foo {
  width: 100vw;
  height: 100vh;
  content: 'baz';
}

Custom Sort Orders

You have the option to create your own custom property sort orders. These are specified in your .sass-lint.yml file as below:

property-sort-order:
  - 1
  -
    order:
      - border
      - display
      - color

When the custom order is specified as above, the following are allowed:

.foo {
  border: 1px solid blue;
  display: block;
  color: red;
}

When the custom order is specified as above, the following are disallowed:

.foo {
  display: block;
  color: red;
  border: 1px solid blue;
}

Ignore Custom Properties

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be allowed

.foo {
  border: 1px solid blue;
  color: red;
  composes: heading;
  display: block;
}

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be disallowed

.foo {
  composes: heading; // not in alphabetical order
  border: 1px solid blue;
  color: red;
  display: block;
}

When ignore-custom-properties: true (assume order: 'alphabetical') the following would be allowed

.foo {
  composes: heading; // custom properties ignored
  border: 1px solid blue;
  color: red;
  display: block;
}

Class Name Format

Rule class-name-format will enforce a convention for class names.

Options

• allow-leading-underscore: true/false (defaults to true)
• convention: 'hyphenatedlowercase' (default), camelcase, snakecase, strictbem, hyphenatedbem, or a Regular Expression that the class name must match (e.g. ^[_A-Z]+$)
• convention-explanation: Custom explanation to display to the user if a class doesn't adhere to the convention
• ignore: Array of names to ignore

Example 1

Settings: - allow-leading-underscore: true - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &._with-leading-underscore {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 2

Settings: - allow-leading-underscore: false - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &.another-hyphenated-lowercase {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

._with-leading-underscore {
  content: '';
}

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 3

Settings: - convention: camelcase

When enabled, the following are allowed:

.camelCase {
  content: '';
}

.foo {
  @extend .anotherCamelCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 4

Settings: - convention: pascalcase

When enabled, the following are allowed:

.PascalCase {
  content: '';
}

.Foo {
  @extend .AnotherPascalCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 5

Settings: - convention: snakecase

When enabled, the following are allowed:

.snake_case {
  content: '';
}

.foo {
  @extend .another_snake_case;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 6

Settings: - convention: strictbem

When enabled, the following are allowed:

.block-name__elem-name {
  content: '';
}

.owner-name_mod-name_mod-val {
  content: '';
}

.block-name__elem-name_mod-bool {
  content: '';
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 7

Settings: - convention: hyphenatedbem

When enabled, the following are allowed:

.site-search {
  color: blue;
  width: 50px;
  height: 100%;
}

.site-search__field {
  text-decoration: underline;
}

.site-search--full {
  color: green;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 8

Settings: - convention: ^[_A-Z]+$ - convention-explanation: 'Class must contain only uppercase letters and underscores'

When enabled, the following are allowed:

.SCREAMING_SNAKE_CASE {
  content: '';
}

.foo {
  @extend .SCREAMING_SNAKE_CASE;
}

When enabled, the following are disallowed:

(Each line with a class will report Class must contain only uppercase letters and underscores when linted.)

.HYPHENATED-UPPERCASE {
  content: '';
}

.snake_case {
  content: '';
}

.foo {
  @extend .camelCase;
}

Class Name Format

Rule class-name-format will enforce a convention for class names.

Options

• allow-leading-underscore: true/false (defaults to true)
• convention: 'hyphenatedlowercase' (default), camelcase, snakecase, strictbem, hyphenatedbem, or a Regular Expression that the class name must match (e.g. ^[_A-Z]+$)
• convention-explanation: Custom explanation to display to the user if a class doesn't adhere to the convention
• ignore: Array of names to ignore

Example 1

Settings: - allow-leading-underscore: true - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &._with-leading-underscore {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 2

Settings: - allow-leading-underscore: false - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &.another-hyphenated-lowercase {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

._with-leading-underscore {
  content: '';
}

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 3

Settings: - convention: camelcase

When enabled, the following are allowed:

.camelCase {
  content: '';
}

.foo {
  @extend .anotherCamelCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 4

Settings: - convention: pascalcase

When enabled, the following are allowed:

.PascalCase {
  content: '';
}

.Foo {
  @extend .AnotherPascalCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 5

Settings: - convention: snakecase

When enabled, the following are allowed:

.snake_case {
  content: '';
}

.foo {
  @extend .another_snake_case;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 6

Settings: - convention: strictbem

When enabled, the following are allowed:

.block-name__elem-name {
  content: '';
}

.owner-name_mod-name_mod-val {
  content: '';
}

.block-name__elem-name_mod-bool {
  content: '';
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 7

Settings: - convention: hyphenatedbem

When enabled, the following are allowed:

.site-search {
  color: blue;
  width: 50px;
  height: 100%;
}

.site-search__field {
  text-decoration: underline;
}

.site-search--full {
  color: green;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 8

Settings: - convention: ^[_A-Z]+$ - convention-explanation: 'Class must contain only uppercase letters and underscores'

When enabled, the following are allowed:

.SCREAMING_SNAKE_CASE {
  content: '';
}

.foo {
  @extend .SCREAMING_SNAKE_CASE;
}

When enabled, the following are disallowed:

(Each line with a class will report Class must contain only uppercase letters and underscores when linted.)

.HYPHENATED-UPPERCASE {
  content: '';
}

.snake_case {
  content: '';
}

.foo {
  @extend .camelCase;
}

Class Name Format

Rule class-name-format will enforce a convention for class names.

Options

• allow-leading-underscore: true/false (defaults to true)
• convention: 'hyphenatedlowercase' (default), camelcase, snakecase, strictbem, hyphenatedbem, or a Regular Expression that the class name must match (e.g. ^[_A-Z]+$)
• convention-explanation: Custom explanation to display to the user if a class doesn't adhere to the convention
• ignore: Array of names to ignore

Example 1

Settings: - allow-leading-underscore: true - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &._with-leading-underscore {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 2

Settings: - allow-leading-underscore: false - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &.another-hyphenated-lowercase {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

._with-leading-underscore {
  content: '';
}

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 3

Settings: - convention: camelcase

When enabled, the following are allowed:

.camelCase {
  content: '';
}

.foo {
  @extend .anotherCamelCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 4

Settings: - convention: pascalcase

When enabled, the following are allowed:

.PascalCase {
  content: '';
}

.Foo {
  @extend .AnotherPascalCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 5

Settings: - convention: snakecase

When enabled, the following are allowed:

.snake_case {
  content: '';
}

.foo {
  @extend .another_snake_case;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 6

Settings: - convention: strictbem

When enabled, the following are allowed:

.block-name__elem-name {
  content: '';
}

.owner-name_mod-name_mod-val {
  content: '';
}

.block-name__elem-name_mod-bool {
  content: '';
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 7

Settings: - convention: hyphenatedbem

When enabled, the following are allowed:

.site-search {
  color: blue;
  width: 50px;
  height: 100%;
}

.site-search__field {
  text-decoration: underline;
}

.site-search--full {
  color: green;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 8

Settings: - convention: ^[_A-Z]+$ - convention-explanation: 'Class must contain only uppercase letters and underscores'

When enabled, the following are allowed:

.SCREAMING_SNAKE_CASE {
  content: '';
}

.foo {
  @extend .SCREAMING_SNAKE_CASE;
}

When enabled, the following are disallowed:

(Each line with a class will report Class must contain only uppercase letters and underscores when linted.)

.HYPHENATED-UPPERCASE {
  content: '';
}

.snake_case {
  content: '';
}

.foo {
  @extend .camelCase;
}

Border Zero

Rule border-zero will enforce whether one should use 0 or none when specifying a zero border value

Options

• convention: '0'/'none' (defaults to 0)

If an invalid convention is provided the rule will default back to convention: '0'. An extra warning/error will also be thrown on line 1 column 1 of a file with a lint issue to inform you of this fact.

Examples

When convention: '0', the following are allowed. When convention: 'none', the following are disallowed:

.foo {
  border: 0;
}

.bar {
  border-right: 0;
}

When convention: 'none', the following are allowed. When convention: '0', the following are disallowed:

.foo {
  border: none;
}

.bar {
  border-left: none;
}

Invalid conventions

When the invalid convention convention: 'zero' is supplied, the following are allowed as the rule defaults to convention: '0'.

.foo {
  border: none;
}

.bar {
  border-left: 0;
}

Class Name Format

Rule class-name-format will enforce a convention for class names.

Options

• allow-leading-underscore: true/false (defaults to true)
• convention: 'hyphenatedlowercase' (default), camelcase, snakecase, strictbem, hyphenatedbem, or a Regular Expression that the class name must match (e.g. ^[_A-Z]+$)
• convention-explanation: Custom explanation to display to the user if a class doesn't adhere to the convention
• ignore: Array of names to ignore

Example 1

Settings: - allow-leading-underscore: true - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &._with-leading-underscore {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 2

Settings: - allow-leading-underscore: false - convention: hyphenatedlowercase

When enabled, the following are allowed:

.hyphenated-lowercase {
  content: '';

  &.another-hyphenated-lowercase {
    content: '';
  }
}

.foo {
  @extend .hyphenated-lowercase;
}

When enabled, the following are disallowed:

._with-leading-underscore {
  content: '';
}

.HYPHENATED-UPPERCASE {
  content: '';
}

.camelCase {
  content: '';

  @extend .snake_case;
}

Example 3

Settings: - convention: camelcase

When enabled, the following are allowed:

.camelCase {
  content: '';
}

.foo {
  @extend .anotherCamelCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 4

Settings: - convention: pascalcase

When enabled, the following are allowed:

.PascalCase {
  content: '';
}

.Foo {
  @extend .AnotherPascalCase;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .snake_case;
}

Example 5

Settings: - convention: snakecase

When enabled, the following are allowed:

.snake_case {
  content: '';
}

.foo {
  @extend .another_snake_case;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 6

Settings: - convention: strictbem

When enabled, the following are allowed:

.block-name__elem-name {
  content: '';
}

.owner-name_mod-name_mod-val {
  content: '';
}

.block-name__elem-name_mod-bool {
  content: '';
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 7

Settings: - convention: hyphenatedbem

When enabled, the following are allowed:

.site-search {
  color: blue;
  width: 50px;
  height: 100%;
}

.site-search__field {
  text-decoration: underline;
}

.site-search--full {
  color: green;
}

When enabled, the following are disallowed:

.HYPHENATED-UPPERCASE {
  content: '';
}

.foo {
  @extend .camelCase;
}

Example 8

Settings: - convention: ^[_A-Z]+$ - convention-explanation: 'Class must contain only uppercase letters and underscores'

When enabled, the following are allowed:

.SCREAMING_SNAKE_CASE {
  content: '';
}

.foo {
  @extend .SCREAMING_SNAKE_CASE;
}

When enabled, the following are disallowed:

(Each line with a class will report Class must contain only uppercase letters and underscores when linted.)

.HYPHENATED-UPPERCASE {
  content: '';
}

.snake_case {
  content: '';
}

.foo {
  @extend .camelCase;
}

Leading Zero

Rule leading-zero will enforce whether or not decimal numbers should include a leading zero.

Options

• include: true/false (defaults to false)

Examples

When include: false, the following are allowed. When include: true, the following are disallowed:

.foo {
  font-size: .5em;
}

When include: true, the following are allowed. When include: false, the following are disallowed:

.foo {
  font-size: 0.5em;
}

Property Sort Order

Rule property-sort-order will enforce the order in which declarations are written.

Options

• order: 'alphabetical', 'concentric', 'recess', 'smacss', or [array of properties] (defaults to alphabetical. Unknown properties are sorted alphabetically)
• ignore-custom-properties: true/false (defaults to false)

Property orders: https://github.com/sasstools/sass-lint/tree/develop/lib/config/property-sort-orders

Examples

When enabled (assuming order: alphabetical), the following are allowed:

.foo {
  content: 'baz';
  height: 100vh;
  width: 100vw;
}

When enabled (assuming order: alphabetical), the following are disallowed:

.foo {
  width: 100vw;
  height: 100vh;
  content: 'baz';
}

Custom Sort Orders

You have the option to create your own custom property sort orders. These are specified in your .sass-lint.yml file as below:

property-sort-order:
  - 1
  -
    order:
      - border
      - display
      - color

When the custom order is specified as above, the following are allowed:

.foo {
  border: 1px solid blue;
  display: block;
  color: red;
}

When the custom order is specified as above, the following are disallowed:

.foo {
  display: block;
  color: red;
  border: 1px solid blue;
}

Ignore Custom Properties

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be allowed

.foo {
  border: 1px solid blue;
  color: red;
  composes: heading;
  display: block;
}

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be disallowed

.foo {
  composes: heading; // not in alphabetical order
  border: 1px solid blue;
  color: red;
  display: block;
}

When ignore-custom-properties: true (assume order: 'alphabetical') the following would be allowed

.foo {
  composes: heading; // custom properties ignored
  border: 1px solid blue;
  color: red;
  display: block;
}

Property Sort Order

Rule property-sort-order will enforce the order in which declarations are written.

Options

• order: 'alphabetical', 'concentric', 'recess', 'smacss', or [array of properties] (defaults to alphabetical. Unknown properties are sorted alphabetically)
• ignore-custom-properties: true/false (defaults to false)

Property orders: https://github.com/sasstools/sass-lint/tree/develop/lib/config/property-sort-orders

Examples

When enabled (assuming order: alphabetical), the following are allowed:

.foo {
  content: 'baz';
  height: 100vh;
  width: 100vw;
}

When enabled (assuming order: alphabetical), the following are disallowed:

.foo {
  width: 100vw;
  height: 100vh;
  content: 'baz';
}

Custom Sort Orders

You have the option to create your own custom property sort orders. These are specified in your .sass-lint.yml file as below:

property-sort-order:
  - 1
  -
    order:
      - border
      - display
      - color

When the custom order is specified as above, the following are allowed:

.foo {
  border: 1px solid blue;
  display: block;
  color: red;
}

When the custom order is specified as above, the following are disallowed:

.foo {
  display: block;
  color: red;
  border: 1px solid blue;
}

Ignore Custom Properties

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be allowed

.foo {
  border: 1px solid blue;
  color: red;
  composes: heading;
  display: block;
}

When ignore-custom-properties: false (assume order: 'alphabetical') the following would be disallowed

.foo {
  composes: heading; // not in alphabetical order
  border: 1px solid blue;
  color: red;
  display: block;
}

When ignore-custom-properties: true (assume order: 'alphabetical') the following would be allowed

.foo {
  composes: heading; // custom properties ignored
  border: 1px solid blue;
  color: red;
  display: block;
}