length-zero-no-unit

Disallow units for zero lengths.

a { top: 0px; }
/**      ↑↑
 * This zero and this type of length unit */

Lengths refer to distance measurements. A length is a dimension, which is a number immediately followed by a unit identifier. However, for zero lengths the unit identifier is optional. The length units are: em, ex, ch, vw, vh, cm, mm, in, pt, pc, px, rem, vmin, and vmax.

This rule ignores lengths within math functions (e.g. calc).

The fix option can automatically fix all of the problems reported by this rule.

Options

true

The following patterns are considered problems:

a { top: 0px }

a { top: 0.000em }

The following patterns are not considered problems:

a { top: 0 } /* no unit */

a { transition-delay: 0s; } /* dimension */

a { top: 2in; }

a { top: 1.001vh }

Optional secondary options

ignore: ["custom-properties"]

"custom-properties"

Ignore units for zero length in custom properties.

The following pattern is not considered a problem:

a { --x: 0px; }

ignoreFunctions: ["/regex/", /regex/, "string"]

Given:

["var", "/^--/"]

The following patterns are not considered problems:

a { top: var(--foo, 0px); }

a { top: --bar(0px); }