css/css-backgrounds/box-shadow-invalid-001.html

<!DOCTYPE html>

  <meta charset="UTF-8">

  <title>CSS Background and Borders Test: invalid box-shadow declarations</title>

  <!--

  Created: May 20th 2023

  Last modified: May 20th 2023

  -->

  <link rel="author" title="Gérard Talbot" href="http://www.gtalbot.org/BrowserBugsSection/css21testsuite/">
  <link rel="help" href="https://www.w3.org/TR/css-backgrounds-3/#box-shadow">
  <link rel="match" href="reference/ref-filled-green-100px-square.xht">

  <meta content="This test checks that 'box-shadow' accepts either the 'none' value or (exclusive or) a comma-separated list of shadows but not both at the same time." name="assert">
  <meta content="invalid" name="flags">

  <!--

  <shadow> = <color>? && [<length>{2} <length [0,∞]>? <length>?] && inset?

  The box-shadow property attaches one or more drop-shadows to
  the box. The property accepts either the none value, which
  indicates no shadows, or a comma-separated list of shadows,
  ordered front to back.

  -->

  <style>
  div
    {
      background-color: red;
      box-shadow: green 100px 100px inset;
      /*
      This inset 'box-shadow' declaration will paint and cover
      the inside of the red square. This way, we verify that
      the UA actually supports 'box-shadow'.
      */
      box-shadow: none, red 0px -100px, red 100px 0px, red 0px 100px, red -100px 0px; /* invalid */
      box-shadow: red 0px -100px, none, red 100px 0px, red 0px 100px, red -100px 0px; /* invalid */
      box-shadow: red 0px -100px, red 100px 0px, none, red 0px 100px, red -100px 0px; /* invalid */
      box-shadow: red 0px -100px, red 100px 0px, red 0px 100px, none, red -100px 0px; /* invalid */
      box-shadow: red 0px -100px, red 100px 0px, red 0px 100px, red -100px 0px, none; /* invalid */
      height: 100px;
      width: 100px;
   }
  </style>

  <p>Test passes if there is a filled green square and <strong>no red</strong>.

  <div></div>