selector-max-compound-selectors

Limit the number of compound selectors in a selector.

   div .bar[data-val] > a.baz + .boom > #lorem {}
/* ↑   ↑                ↑       ↑       ↑
   ↑   ↑                ↑       ↑       ↑
  Lv1 Lv2              Lv3     Lv4     Lv5  -- these are compound selectors */

A compound selector is a chain of one or more simple (tag, class, ID, universal, attribute) selectors. If there is more than one compound selector in a complete selector, they will be separated by combinators (e.g. , +, >). One reason why you might want to limit the number of compound selectors is described in the SMACSS book.

This rule resolves nested selectors before counting the depth of a selector. Each selector in a selector list is evaluated separately.

warning

The :not() pseudo-class is considered one compound selector irrespective to the complexity of the selector inside it. The rule does process that inner selector, but does so separately, independent of the main selector.

The message secondary option can accept the arguments of this rule.

Options

int: Maximum compound selectors allowed.

For example, with 3:

The following patterns are considered problems:

.foo .bar .baz .lorem {}

.foo .baz {
  & > .bar .lorem {}
}

The following patterns are not considered problems:

div {}

.foo div {}

#foo #bar > #baz {}

.foo + div :not (a b ~ c) {} /* `a b ~ c` is inside `:not()`, so it is evaluated separately */

Optional secondary options

ignoreSelectors: ["/regex/", /regex/, "non-regex"]

Ignore some compound selectors. This may be useful for deep selectors like Vue's ::v-deep or Angular's ::ng-deep that behave more like combinators than compound selectors.

For example, with 2.

Given:

["::v-deep", "/ignored/", ":not"]

The following patterns are considered problems:

.foo .bar ::v-deep .baz {}

p a :not(.foo .bar .baz) {}

.foo .bar > .baz.ignored {}

.foo .bar > .ignored.baz {}

The following patterns are not considered problems:

.foo::v-deep .bar {}

.foo ::v-deep .baz {}

p a :not(.foo .bar) {}

.foo {
  &.some-ignored-class ::v-deep > .bar {}
}

.foo .bar > .ignored.ignored {}

.foo .bar > .ignored .ignored {}