Nesting Depth

Rule nesting-depth will enforce how deeply a selector can be nested.

Options

• max-depth: number (defaults to 2)

Examples

When enabled (assuming max-depth: 2) the deepest element (&:hover and &--modifier) are at at depth 2. Any nested selector deeper is disallowed:

.foo {
  .baz {
    &:hover {
      // Deepest Nest Allowed
    }
  }
}

.block {
  &__element {
    &--modifier {
      // Deepest Nest Allowed
    }
  }
}

Nesting Depth

Rule nesting-depth will enforce how deeply a selector can be nested.

Options

• max-depth: number (defaults to 2)

Examples

When enabled (assuming max-depth: 2) the deepest element (&:hover and &--modifier) are at at depth 2. Any nested selector deeper is disallowed:

.foo {
  .baz {
    &:hover {
      // Deepest Nest Allowed
    }
  }
}

.block {
  &__element {
    &--modifier {
      // Deepest Nest Allowed
    }
  }
}

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;
      }
    }
  }
}

No CSS Comments

Rule no-css-comments will enforce the use of Sass single-line comments and disallow CSS comments. Bang comments (/*! */, will be printed even in minified mode) are still allowed.

Examples

When enabled the following are allowed:

// This is a good comment

// =========
// This is a good comment
// =========

//////////////////
// This is a good comment
//////////////////

/*! This is a good bang comment */

/*!
  * This is a good bang comment
**/

When enabled the following are disallowed:

/* This comment will appear in your compiled css */

/*
 * Mulitline comments are bad
 */

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;
      }
    }
  }
}

No Mergeable Selectors

Rule no-mergeable-selectors will enforce that selectors aren't repeated and that their properties are merged. You may also pass a whitelist of selectors you wish to exclude from merging.

Options

• whitelist: [array of selectors] (defaults to empty array [])

Examples

When enabled with the default options, the following will generate a warning/error :

.foo {
  content: 'bar';
}

//duplicate selector
.foo {
  color: red;
}

h1,
h2,
h3 {
  content: '';
}

// mergeable idents
h1, h2, h3 {
  content: '';
}

.test {
  .bar {
    color: blue;
  }
}

// 2 mergeable selectors .test & .test .bar
.test {
  .bar {
    color: red;
  }
}

When whitelist: ['div p', 'div a'] the following will be allowed and no longer generate any mergeable warnings or errors:

div p {
  color: red;
}

// will not be warned as mergeable / duplicate
div p {
  content: '';
}

div a {
  color: blue;
}

// will not be warned as mergeable / duplicate
div a {
  content: '';
}

Note for Sass syntax users

Due to a bug in the current version of the AST we use, gonzales-pe, we are currently unable to enforce this rule within media queries, SCSS syntax is unaffected. We hope to rectify this soon.

No CSS Comments

Rule no-css-comments will enforce the use of Sass single-line comments and disallow CSS comments. Bang comments (/*! */, will be printed even in minified mode) are still allowed.

Examples

When enabled the following are allowed:

// This is a good comment

// =========
// This is a good comment
// =========

//////////////////
// This is a good comment
//////////////////

/*! This is a good bang comment */

/*!
  * This is a good bang comment
**/

When enabled the following are disallowed:

/* This comment will appear in your compiled css */

/*
 * Mulitline comments are bad
 */

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;
      }
    }
  }
}

No CSS Comments

Rule no-css-comments will enforce the use of Sass single-line comments and disallow CSS comments. Bang comments (/*! */, will be printed even in minified mode) are still allowed.

Examples

When enabled the following are allowed:

// This is a good comment

// =========
// This is a good comment
// =========

//////////////////
// This is a good comment
//////////////////

/*! This is a good bang comment */

/*!
  * This is a good bang comment
**/

When enabled the following are disallowed:

/* This comment will appear in your compiled css */

/*
 * Mulitline comments are bad
 */

No CSS Comments

Rule no-css-comments will enforce the use of Sass single-line comments and disallow CSS comments. Bang comments (/*! */, will be printed even in minified mode) are still allowed.

Examples

When enabled the following are allowed:

// This is a good comment

// =========
// This is a good comment
// =========

//////////////////
// This is a good comment
//////////////////

/*! This is a good bang comment */

/*!
  * This is a good bang comment
**/

When enabled the following are disallowed:

/* This comment will appear in your compiled css */

/*
 * Mulitline comments are bad
 */

No CSS Comments

Rule no-css-comments will enforce the use of Sass single-line comments and disallow CSS comments. Bang comments (/*! */, will be printed even in minified mode) are still allowed.

Examples

When enabled the following are allowed:

// This is a good comment

// =========
// This is a good comment
// =========

//////////////////
// This is a good comment
//////////////////

/*! This is a good bang comment */

/*!
  * This is a good bang comment
**/

When enabled the following are disallowed:

/* This comment will appear in your compiled css */

/*
 * Mulitline comments are bad
 */

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;
      }
    }
  }
}

No CSS Comments

Rule no-css-comments will enforce the use of Sass single-line comments and disallow CSS comments. Bang comments (/*! */, will be printed even in minified mode) are still allowed.

Examples

When enabled the following are allowed:

// This is a good comment

// =========
// This is a good comment
// =========

//////////////////
// This is a good comment
//////////////////

/*! This is a good bang comment */

/*!
  * This is a good bang comment
**/

When enabled the following are disallowed:

/* This comment will appear in your compiled css */

/*
 * Mulitline comments are bad
 */

No Vendor Prefixes

Rule no-vendor-prefixes will enforce that vendor prefixes are not allowed to be used.

List of prefixes affected by default: * webkit * moz * ms

Options

• additional-identifiers: [array of additional prefixes to check for] (defaults to empty array [])
• excluded-identifiers: [array of prefixes to exclude checking for] (defaults to empty array [])
• ignore-non-standard: true:false (defaults to false)

Examples

When enabled, the following are disallowed:

@-webkit-keyframes anim {
  0% { opacity: 0; }
}

.ms-block {
  -ms-hyphenate-limit-lines: no-limit;
}

::-moz-placeholder {
  content: '';
}

.foo {
  -webkit-transition: none;
}

.bar {
  position: -moz-sticky;
}

Additional Identifiers

When additional-identifiers contains a custom prefix value of khtml as show below

no-vendor-prefixes:
  - 1
  -
    additional-identifiers:
      - khtml

The following would now also be disallowed

.baz {
  position: -khtml-sticky;
}

Excluded Identifiers

When excluded-identifiers contains currently disallowed prefix values such as webkit and moz as show below

no-vendor-prefixes:
  - 1
  -
    excluded-identifiers:
      - webkit
      - moz

The following would now be allowed

@-webkit-keyframes anim {
  0% { opacity: 0; }
}

::-moz-placeholder {
  content: '';
}

.foo {
  -webkit-transition: none;
}

.bar {
  position: -moz-sticky;
}

While the following would remain disallowed

.ms-block {
  -ms-hyphenate-limit-lines: no-limit;
}

Ignore Non Standard

ignore-non-standard is an option that allows you to specify whether only standard properties from our properties list should be affected by this rule or if any prefixed property / element should be affected.

When ignore-non-standard is set to false the following are disallowed, when ignore-non-standard is set to true the following are allowed:

html {
  -webkit-tap-highlight-color: $link-color-hover;
}

button::-moz-focus-inner,
input::-moz-focus-inner {
  border: 0;
  padding: 0;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  height: auto;
}