chromium/third_party/blink/web_tests/external/wpt/css/cssom/cssstyledeclaration-csstext-setter.window.js

// https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-csstext

[
  document.body,
  document.createElement("cool-beans")
].forEach(element => {
  test(t => {
    t.add_cleanup(() => element.removeAttribute("style"));

    element.style.background = "red";
    assert_equals(element.getAttribute("style"), "background: red;");

    element.style.cssText = "background:red";
    assert_equals(element.getAttribute("style"), "background: red;");
  }, `cssText setter should set style attribute even when there are no style changes (${element.localName})`);

  test(t => {
    t.add_cleanup(() => element.removeAttribute("style"));

    element.setAttribute("style", "background:   red");
    assert_equals(element.getAttribute("style"), "background:   red");

    element.style.cssText = "background:red";
    assert_equals(element.getAttribute("style"), "background: red;");
  }, `cssText setter should set style attribute even when there are no style changes, part 2 (${element.localName})`);

  test(t => {
    t.add_cleanup(() => element.removeAttribute("style"));

    element.setAttribute("style", "background:   red");
    assert_equals(element.getAttribute("style"), "background:   red");

    element.style.cssText = "background:red "; // trailing space
    assert_equals(element.getAttribute("style"), "background: red;");
  }, `cssText setter should set style attribute even when there are no style changes, part 3 (${element.localName})`);

  test(t => {
    t.add_cleanup(() => element.removeAttribute("style"));

    element.setAttribute("style", "background:   red");
    assert_equals(element.getAttribute("style"), "background:   red");

    element.style.cssText = "background:red;";
    assert_equals(element.getAttribute("style"), "background: red;");
  }, `cssText setter should set style attribute even when there are no style changes, part 4 (${element.localName})`);
});

test(t => {
  const style = document.createElement("style");
  t.add_cleanup(() => {
    document.body.removeAttribute("style");
    style.remove();
  });
  style.textContent = `[style="background: red;"] { background:white !important; }`;
  document.body.appendChild(style);

  document.body.setAttribute("style", "background:red");
  assert_true(document.body.matches("[style=\"background:red\"]"));
  assert_equals(getComputedStyle(document.body).backgroundColor, "rgb(255, 0, 0)");

  document.body.style.cssText = "background:red";
  assert_equals(getComputedStyle(document.body).backgroundColor, "rgb(255, 255, 255)");
  assert_true(document.body.matches("[style=\"background: red;\"]"));
}, `cssText setter and selector invalidation`);