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

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

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;
}

Indentation

Rule indentation will enforce an indentation size (tabs and spaces) and it will also ensure that tabs and spaces are not mixed.

The mixed spaces and tabs warnings check will take into account what you have set in your config file whether it should expect to see spaces or tabs. If it encounters a tab anywhere in a file when your rule config doesn't specify tabs it will flag a lint warning, Similarly for any whitespace using spaces when tabs are specified. Obviously spaces between properties and values etc are ignored.

Options

• size: number or 'tab' (defaults to 2 spaces)

Examples

When enabled (assuming size: 2) the following are allowed:

.foo {
  content: 'bar';

  .baz {
    content: 'qux';

    // Waldo
    &--waldo {
      content: 'alpha';
    }
  }
}

When enabled (assuming size: 2) the following are disallowed:

.foo {
content: 'bar';
   .baz {
  content: 'qux';
  // Waldo
      &--waldo {
        content: 'alpha';
      }
    }
}

Indentation

Rule indentation will enforce an indentation size (tabs and spaces) and it will also ensure that tabs and spaces are not mixed.

The mixed spaces and tabs warnings check will take into account what you have set in your config file whether it should expect to see spaces or tabs. If it encounters a tab anywhere in a file when your rule config doesn't specify tabs it will flag a lint warning, Similarly for any whitespace using spaces when tabs are specified. Obviously spaces between properties and values etc are ignored.

Options

• size: number or 'tab' (defaults to 2 spaces)

Examples

When enabled (assuming size: 2) the following are allowed:

.foo {
  content: 'bar';

  .baz {
    content: 'qux';

    // Waldo
    &--waldo {
      content: 'alpha';
    }
  }
}

When enabled (assuming size: 2) the following are disallowed:

.foo {
content: 'bar';
   .baz {
  content: 'qux';
  // Waldo
      &--waldo {
        content: 'alpha';
      }
    }
}

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;
}

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;
}

Zero Unit

Rule zero-unit will enforce whether or not values of 0 used for length should be unitless.

Options

• include: true/false (defaults to false)

Examples

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

.foo {
  margin: 0;
}

.bar {
  padding: 5px 0 0;
}

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

.foo {
  margin: 0px;
}

.bar {
  padding: 5px 0px 0px;
}

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;
}

Force Pseudo Nesting

Rule force-pseudo-nesting will enforce the nesting of pseudo elements/classes.

Examples

When enabled, the following are disallowed: ```scss p:nth-of-type(2) { margin: 0; }

.parent { .child { p::first-line { color: #ff0000; } } }

.parent { .child { .sub p::first-line { color: #ff0000; } } } ```

When enabled, the following are allowed:

p {
  &:nth-of-type(2) {
    margin: 0;
  }
}

.parent {
  .child {
    p {
      &::first-line {
        color: #ff0000;
      }
    }
  }
}

.parent {
  .child {
    .sub p {
      &::first-line {
        color: #ff0000;
      }
    }
  }
}

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;
}

No Important

Rule no-important will enforce that important declarations are not allowed to be used.

Examples

When enabled, the following are disallowed:

.foo {
  content: 'bar' !important;
}

Space Before Bang

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

Options

• include: true/false (defaults to true)

Examples

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

.foo {
  content: 'bar' !important;
}

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

.foo {
  content: 'bar'!important;
}

Space Before Bang

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

Options

• include: true/false (defaults to true)

Examples

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

.foo {
  content: 'bar' !important;
}

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

.foo {
  content: 'bar'!important;
}