stylelint-config-drupal/test/format-properties.css

Drupal stylelint configuration

/**
 * @file
 * Format properties test.
 *
 * @see https://www.drupal.org/docs/develop/standards/css/css-formatting-guidelines#s-properties
 */

/**
 * - In a declaration, the property name should be immediately followed by a
 *   colon, then a single space, and then the property’s value.
 * - Include a semi-colon at the end of all declarations, including the last
 *   declaration in a declaration block.
 */
.test {
  color: red;
}

/**
 * When hex values are used for colors, use lowercase and, if possible, the
 * shorthand syntax, e.g. #aaa. Colors may be expressed with any valid CSS
 * value, such as hex value, color keyword, rgb() or rgba().
 */
.test {
  background-color: #fff;
}
.test {
  background-color: #030303;
}
.test {
  background-color: rgba(100, 100, 100, 1);
}

/**
 * For property values that require quotes, use double quotes instead of single
 * quotes, e.g. font-family: "Arial Black", Arial, sans-serif; and
 * content: " ";.
 */
.test {
  content: " ";
  font-family: "Arial Black", Arial, sans-serif;
}

/**
 * If a property does not require quotes (e.g. url(), do not add them. This
 * means background-image: url(path/image.png) instead of
 * background-image: url("path/image.png")
 */
.test {
  background-image: url(path/image.png);
}

/**
 * Use rem units preceded by px units for a safe fallback, unless it creates an
 * undesired effect.
 */
.test {
  width: 24px;
  width: 1.5rem;
}

/**
 * Quote attribute values in selectors, e.g. input[type="checkbox"].
 */
.test[type="checkbox"] {
  content: "";
}

/**
 * Where allowed, avoid specifying units for zero-values, e.g. use margin: 0;
 * instead of margin: 0px;.
 */
.test {
  text-shadow: 0 0 2px #ddd;
}

/**
 * Include a space after each comma in comma-separated property or function
 * values.
 */
.test {
  background: #000, #111, #222;
}

/**
 * - Do not use spaces around the parentheses in a function,
 * e.g. color: rgba(0, 0, 0, 0.8);
 * - Use lower case function names, correct: color: rgba(0, 0, 0, 0.8);
 * incorrect: color: RGBA(0, 0, 0, 0.8);
 */
.test {
  color: rgba(0, 0, 0, 0.8);
}