css/css-shadow-parts/interaction-with-pseudo-elements.html

<!DOCTYPE html>
<html>
  <head>
    <title>CSS Shadow Parts - Interaction with pseudo-elements</title>
    <meta href="mailto:fergal@chromium.org" rel="author" title="Fergal Daly">
    <link href="http://www.google.com/" rel="author" title="Google">
    <link href="https://drafts.csswg.org/css-shadow-parts/" rel="help">
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <script src="support/shadow-helper.js"></script>
  </head>
  <body>
    <style>
      #c-e::part(before-p)::before { color: green; }
      #c-e::part(after-p)::after { color: green; }
      #c-e::part(placeholder-p)::placeholder { color: green; }
      #c-e::part(selection-p)::selection { color: green; }
      #c-e::part(first-line-p)::first-line { color: green; }
      #c-e::part(first-letter-p)::first-letter { color: green; }
    </style>
    <script>installCustomElement("custom-element", "custom-element-template");</script>
    <template id="custom-element-template">
      <style>
        #before-i::before { content: "this text"; color: red; }
        #after-i::after { content: "this text"; color: red; }
        #placeholder-i::placeholder { color: red; }
        #selection-i::selection { color: red; }
        #first-line-i::first-line { color: red; }
        #first-letter-i::first-letter { color: red; }
      </style>
      <div>
        The following text should be green:
        <span id="before-i" part="before-p"></span>
      </div>
      <div>
        The following text should be green:
        <span id="after-i" part="after-p"></span>
      </div>
      <div>
        The following text should be green:
        <input id="placeholder-i" part="placeholder-p" placeholder="this text"></input>
      </div>
      <div>
        The selected text should be green:
        <div id="selection-i" part="selection-p">select some text</div>
      </div>
      <div>
        The following text should be green:
        <div id="first-line-i" part="first-line-p">this text<br>Not this</div>
      </div>
      <div>
        The first letter should be green:
        <div id="first-letter-i" part="first-letter-p"><p>this text</p></div>
      </div>
    </template>
    <custom-element id="c-e"></custom-element>
    <script>
      "use strict";
      const colorGreen = "rgb(0, 128, 0)";
      test(function() {
        const el = getElementByShadowIds(document, ["c-e", "before-i"]);
        assert_equals(window.getComputedStyle(el, '::before').color, colorGreen);
      }, "::before in selected host is styled");
      test(function() {
        const el = getElementByShadowIds(document, ["c-e", "after-i"]);
        assert_equals(window.getComputedStyle(el, '::after').color, colorGreen);
      }, "::after in selected host is styled");
      test(function() {
        const el = getElementByShadowIds(document, ["c-e", "placeholder-i"]);
        assert_equals(window.getComputedStyle(el, '::placeholder').color, colorGreen);
      }, "::placeholder in selected host is styled");
      test(function() {
        const el = getElementByShadowIds(document, ["c-e", "selection-i"]);
        assert_equals(window.getComputedStyle(el, '::selection').color, colorGreen);
      }, "::selection in selected host is styled");
      test(function() {
        const el = getElementByShadowIds(document, ["c-e", "first-line-i"]);
        assert_equals(window.getComputedStyle(el, '::first-line').color, colorGreen);
      }, "::first-line in selected host is styled");
      test(function() {
        const el = getElementByShadowIds(document, ["c-e", "first-letter-i"]);
        assert_equals(window.getComputedStyle(el, '::first-letter').color, colorGreen);
      }, "::first-letter in selected host is styled");
    </script>
  </body>
</html>