test_getMatchingCSSRules_slotted.html

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<!DOCTYPE html>

<title>Test getMatchingCSSRules for pseudo elements</title>

<script src="/tests/SimpleTest/SimpleTest.js"></script>

<link rel="stylesheet" href="/tests/SimpleTest/test.css">

<div id="host">

  <test-element id="test1" slot="slot1">test1</test-element>

  <test-element id="test2" slot="slot2">test2</test-element>

</div>

<script>

  const host = document.getElementById("host");

  const shadow = host.attachShadow({ mode: "open" });

  shadow.innerHTML = `

    <style>

      #outer ::slotted(test-element) {

        color: red;

    </style>

    <div id="outer">

      <slot name="slot1"></slot>

    </div>

    <div id="nested">

      <slot name="slot2"></slot>

    </div>

`;

  const nested = shadow.querySelector("#nested").attachShadow({ mode: "open" });

  nested.innerHTML = `

    <style>

      #inner ::slotted(test-element) {

        font-weight: bold;

    </style>

    <div id="inner">

      <slot></slot>

    </div>

`;

  const InspectorUtils = SpecialPowers.InspectorUtils;

  function checkElementRules(id, text, property) {

    const element = document.getElementById(id);

    let slottedRules = InspectorUtils.getMatchingCSSRules(element);

    is(slottedRules.length, 1, "Slotted element has expected number of rules.");

    let slottedText = slottedRules[0].cssText;

    ok(slottedText.includes(text), "Slotted node has expected style content.");

    ok(slottedText.includes(property), "Has expected property.");

  info("Check that slotted rules are retrieved");

  checkElementRules("test1", "#outer ::slotted(test-element)", "color");

  info("Check that slotted rules are also retrieved for nested slots");

  checkElementRules("test2", "#inner ::slotted(test-element)", "font-weight");

</script>