<!DOCTYPE html>
<meta charset="UTF-8">
<link rel="author" title="Xidorn Quan" href="mailto:me@upsuper.org">
<link rel="help" href="https://drafts.csswg.org/cssom-1/#css-declaration-blocks">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
function createTestElement(style) {
  let wrapper = document.createElement("div");
  wrapper.innerHTML = `<div id="test" style="${style}"></div>`;
  return wrapper.querySelector("#test");
}

test(function() {
  let elem = createTestElement("z-index: 10;");
  assert_equals(elem.style.cssText, "z-index: 10;");
}, "Style attribute should create CSS declaration block based on its content");

test(function() {
  let elem = createTestElement("z-index: 20;");
  let style = elem.style;
  assert_equals(style.cssText, "z-index: 20;");
  function assert_css_text(value, action) {
    assert_equals(style.cssText, value, "CSS declaration block after " + action);
  }
  elem.setAttribute("style", "z-index: 21;");
  assert_css_text("z-index: 21;", "changing the style attribute");
  elem.removeAttribute("style");
  assert_css_text("", "removing the style attribute");
  elem.setAttribute("style", "position: absolute;");
  assert_css_text("position: absolute;", "adding style attribute again");
}, "Changes to style attribute should reflect on CSS declaration block");

test(function() {
  let elem = createTestElement("z-index: 30;");
  let style = elem.style;
  assert_equals(style.cssText, "z-index: 30;");
  function assert_attr(value, action) {
    assert_equals(elem.getAttribute("style"), value, "style attribute after " + action);
  }
  style.setProperty("z-index", "31");
  assert_attr("z-index: 31;", "changing property in CSS declaration block");
  style.removeProperty("z-index");
  assert_attr("", "removing property from CSS declaration block");
  style.setProperty("position", "absolute");
  assert_attr("position: absolute;", "adding property to CSS declaration block");
  style.cssText = "z-index: 32;";
  assert_attr("z-index: 32;", "changing cssText");
  style.cssText = "z-index: 33; invalid";
  assert_attr("z-index: 33;", "changing cssText to a partial invalid value");
}, "Changes to CSS declaration block should reflect on style attribute");

test(function() {
  let elem = createTestElement("z-index: 40;");
  let style = elem.style;
  assert_equals(style.cssText, "z-index: 40;");
  // Create an observer for the element.
  let observer = new MutationObserver(function() {});
  observer.observe(elem, {attributes: true, attributeOldValue: true});
  function assert_record_with_old_value(oldValue, action) {
    let records = observer.takeRecords();
    assert_equals(records.length, 1, "number of mutation records after " + action);
    let record = records[0];
    assert_equals(record.type, "attributes", "mutation type after " + action);
    assert_equals(record.attributeName, "style", "mutated attribute after " + action);
    assert_equals(record.oldValue, oldValue, "old value after " + action);
  }
  style.setProperty("z-index", "41");
  assert_record_with_old_value("z-index: 40;", "changing property in CSS declaration block");
  style.cssText = "z-index: 42;";
  assert_record_with_old_value("z-index: 41;", "changing cssText");
  style.cssText = "z-index: 42;";
  assert_record_with_old_value("z-index: 42;", "changing cssText with the same content");
  style.removeProperty("z-index");
  assert_record_with_old_value("z-index: 42;", "removing property from CSS declaration block");
  // Mutation to shorthand properties should also trigger only one mutation record.
  style.setProperty("margin", "1px");
  assert_record_with_old_value("", "adding shorthand property to CSS declaration block");
  style.removeProperty("margin");
  assert_record_with_old_value("margin: 1px;", "removing shorthand property from CSS declaration block");
  // Final sanity check.
  assert_equals(elem.getAttribute("style"), "");
}, "Changes to CSS declaration block should queue mutation record for style attribute");

test(function() {
  let elem = createTestElement("z-index: 50; invalid");
  let style = elem.style;
  assert_equals(style.cssText, "z-index: 50;");
  // Create an observer for the element.
  let observer = new MutationObserver(function() {});
  observer.observe(elem, {attributes: true});
  function assert_no_record(action) {
    let records = observer.takeRecords();
    assert_equals(records.length, 0, "expect no record after " + action);
  }
  style.setProperty("z-index", "invalid");
  assert_no_record("setting invalid value to property");
  // Longhand property.
  style.removeProperty("position");
  assert_no_record("removing non-existing longhand property");
  style.setProperty("position", "");
  assert_no_record("setting empty string to non-existing longhand property");
  // Shorthand property.
  style.removeProperty("margin");
  assert_no_record("removing non-existing shorthand property");
  style.setProperty("margin", "");
  assert_no_record("setting empty string to non-existing shorthand property");
  // Check that the value really isn't changed.
  assert_equals(elem.getAttribute("style"), "z-index: 50; invalid",
                "style attribute after removing non-existing properties");
}, "Removing non-existing property or setting invalid value on CSS declaration block shouldn't queue mutation record");

test(function() {
  let elem = createTestElement("background-image: url(./);");
  let style = elem.style;
  let base = document.createElement("base");
  base.href = "/";
  document.body.appendChild(elem);
  let originalComputedValue = getComputedStyle(elem).backgroundImage;
  document.head.appendChild(base);
  this.add_cleanup(() => {
    document.head.removeChild(base);
    document.body.removeChild(elem);
  });
  style.setProperty("background-color", "green");
  assert_equals(getComputedStyle(elem).backgroundImage, originalComputedValue,
                "getComputedStyle(elem).backgroundImage after setting background-color");
  style.setProperty("background-image", "url(./)");
  assert_not_equals(getComputedStyle(elem).backgroundImage, originalComputedValue,
                    "getComputedStyle(elem).backgroundImage after setting background-image");
}, "Changes to CSS declaration block after a base URL change");

test(function() {
  let e1 = document.createElement('div');
  let e2 = document.createElement('div');
  document.body.append(e1, e2);
  this.add_cleanup(() => {
    e1.remove();
    e2.remove();
  });
  e1.style.cssText = "all:revert;border-bottom-left-radius:1px;";
  e2.style.cssText = "all:unset;border-bottom-left-radius:1px;";
  let processed = e1.style.cssText.split(';')
    .map(x => x.replace(/revert$/, 'unset')).join(';');
  assert_equals(processed, e2.style.cssText);
}, "Expansion of all:unset and all:revert treated identically");
</script>