README.md

declaration-nested-properties-no-divided-groups

Disallow nested properties of the same "namespace" be divided into multiple groups.

/* Such groups: */
font: { /* `font` is a "namespace" */
  size: 16px;
  weight: 700;
}

A "namespace" is everything before the first - in property names, e.g. margin in margin-bottom. It is the "namespace" that is used as a root identifier for a nested properties group (font in the example above).

Sass official docs on nested properties.

The following patterns are considered warnings:

a {
  background: url(img.png) center {
    size: auto;
  }
  background: {
    repeat: no-repeat;
  }
}

The following patterns are not considered warnings:

a {
  background: url(img.png) center {
    size: auto;
  }
  background-repeat: no-repeat;
}

a {
  background: url(img.png) center no-repeat {
    color: red;
  }
  margin: 10px {
    left: 1px;
  }
}

a {
  background: url(img.png) center {
    size: auto;
  }
  background :red {
    repeat: no-repeat;
  }
}
/* There is no space after the colon in `background :red` so it is considered A SELECTOR and is compiled into: 

a background :red {
  color: blue;
}

*/