1 files changed, 245 insertions, 0 deletions
diff --git a/testing/web-platform/tests/css/css-properties-values-api/resources/utils.js b/testing/web-platform/tests/css/css-properties-values-api/resources/utils.js
new file mode 100644
index 0000000000..a952a4feed
--- /dev/null
+++ b/testing/web-platform/tests/css/css-properties-values-api/resources/utils.js
@@ -0,0 +1,245 @@
+let next_property_id = 1;
+
+// Generate a unique property name on the form --prop-N.
+function generate_name() {
+  return `--prop-${next_property_id++}`;
+}
+
+// Produce a compatible initial value for the specified syntax.
+function any_initial_value(syntax) {
+  let components = syntax.split('|').map(x => x.trim())
+  let first_component = components[0];
+
+  if (first_component.endsWith('+') || first_component.endsWith('#'))
+    first_component = first_component.slice(0, -1);
+
+  switch (first_component) {
+    case '*':
+    case '<custom-ident>':
+      return 'NULL';
+    case '<angle>':
+      return '0deg';
+    case '<color>':
+      return 'rgb(0, 0, 0)';
+    case '<image>':
+    case '<url>':
+      return 'url(0)';
+    case '<integer>':
+    case '<length-percentage>':
+    case '<length>':
+    case '<number>':
+      return '0';
+    case '<percentage>':
+      return '0%';
+    case '<resolution>':
+      return '0dpi';
+    case '<time>':
+      return '0s';
+    case '<transform-function>':
+    case '<transform-list>':
+      return 'matrix(0, 0, 0, 0, 0, 0)';
+    default:
+      // We assume syntax is a specific custom ident.
+      return first_component;
+  }
+}
+
+// Registers a unique property on the form '--prop-N' and returns the name.
+// Any value except 'syntax' may be omitted, in which case the property will
+// not inherit, and some undefined (but compatible) initial value will be
+// generated. If a single string is used as the argument, it is assumed to be
+// the syntax.
+function generate_property(reg) {
+  // Verify that only valid keys are specified. This prevents the caller from
+  // accidentally supplying 'inherited' instead of 'inherits', for example.
+  if (typeof(reg) === 'object') {
+    const permitted = new Set(['name', 'syntax', 'initialValue', 'inherits']);
+    if (!Object.keys(reg).every(k => permitted.has(k)))
+      throw new Error('generate_property: invalid parameter');
+  }
+
+  let syntax = typeof(reg) === 'string' ? reg : reg.syntax;
+  let initial = typeof(reg.initialValue) === 'undefined' ? any_initial_value(syntax)
+                                                         : reg.initialValue;
+  let inherits = typeof(reg.inherits) === 'undefined' ? false : reg.inherits;
+
+  let name = generate_name();
+  CSS.registerProperty({
+    name: name,
+    syntax: syntax,
+    initialValue: initial,
+    inherits: inherits
+  });
+  return name;
+}
+
+function all_syntaxes() {
+  return [
+    '*',
+    '<angle>',
+    '<color>',
+    '<custom-ident>',
+    '<image>',
+    '<integer>',
+    '<length-percentage>',
+    '<length>',
+    '<number>',
+    '<percentage>',
+    '<resolution>',
+    '<time>',
+    '<transform-function>',
+    '<transform-list>',
+    '<url>'
+  ]
+}
+
+function with_style_node(text, fn) {
+  let node = document.createElement('style');
+  node.textContent = text;
+  try {
+    document.body.append(node);
+    fn(node);
+  } finally {
+    node.remove();
+  }
+}
+
+function with_at_property(desc, fn) {
+  let name = typeof(desc.name) === 'undefined' ? generate_name() : desc.name;
+  let text = `@property ${name} {`;
+  if (typeof(desc.syntax) !== 'undefined')
+    text += `syntax:${desc.syntax};`;
+  if (typeof(desc.initialValue) !== 'undefined')
+    text += `initial-value:${desc.initialValue};`;
+  if (typeof(desc.inherits) !== 'undefined')
+    text += `inherits:${desc.inherits};`;
+  text += '}';
+  with_style_node(text, (node) => fn(name, node.sheet.rules[0]));
+}
+
+function test_with_at_property(desc, fn, description) {
+  test(() => with_at_property(desc, fn), description);
+}
+
+function test_with_style_node(text, fn, description) {
+  test(() => with_style_node(text, fn), description);
+}
+
+function animation_test(property, values, description) {
+  const name = generate_name();
+  property.name = name;
+  CSS.registerProperty(property);
+
+  test(() => {
+    const duration = 1000;
+    const keyframes = {};
+    keyframes[name] = values.keyframes;
+
+    const iterations = 3;
+    const composite = values.composite || "replace";
+    const iterationComposite = values.iterationComposite || "replace";
+    const animation = target.animate(keyframes, { composite, iterationComposite, iterations, duration });
+    animation.pause();
+    // We seek to the middle of the third iteration which will allow to test cases where
+    // iterationComposite is set to something other than "replace".
+    animation.currentTime = duration * 2.5;
+
+    const assert_equals_function = values.assert_function || assert_equals;
+    assert_equals_function(getComputedStyle(target).getPropertyValue(name), values.expected);
+  }, description);
+};
+
+function discrete_animation_test(syntax, fromValue, toValue, description) {
+  test(() => {
+    const name = generate_name();
+
+    CSS.registerProperty({
+      name,
+      syntax,
+      inherits: false,
+      initialValue: fromValue
+    });
+
+    const duration = 1000;
+    const keyframes = [];
+    keyframes[name] = toValue;
+    const animation = target.animate(keyframes, duration);
+    animation.pause();
+
+    const checkAtProgress = (progress, expected) => {
+      animation.currentTime = duration * 0.25;
+      assert_equals(getComputedStyle(target).getPropertyValue(name), fromValue, `The correct value is used at progress = ${progress}`);
+    };
+
+    checkAtProgress(0, fromValue);
+    checkAtProgress(0.25, fromValue);
+    checkAtProgress(0.49, fromValue);
+    checkAtProgress(0.5, toValue);
+    checkAtProgress(0.75, toValue);
+    checkAtProgress(1, toValue);
+  }, description || `Animating a custom property of type ${syntax} is discrete`);
+}
+
+function transition_test(options, description) {
+  promise_test(async () => {
+    const customProperty = generate_name();
+
+    options.transitionProperty ??= customProperty;
+
+    CSS.registerProperty({
+      name: customProperty,
+      syntax: options.syntax,
+      inherits: false,
+      initialValue: options.from
+    });
+
+    assert_equals(getComputedStyle(target).getPropertyValue(customProperty), options.from, "Element has the expected initial value");
+
+    const transitionEventPromise = new Promise(resolve => {
+      let listener = event => {
+          target.removeEventListener("transitionrun", listener);
+          assert_equals(event.propertyName, customProperty, "TransitionEvent has the expected property name");
+          resolve();
+      };
+      target.addEventListener("transitionrun", listener);
+    });
+
+    target.style.transition = `${options.transitionProperty} 1s -500ms linear`;
+    if (options.behavior) {
+      target.style.transitionBehavior = options.behavior;
+    }
+    target.style.setProperty(customProperty, options.to);
+
+    const animations = target.getAnimations();
+    assert_equals(animations.length, 1, "A single animation is running");
+
+    const transition = animations[0];
+    assert_class_string(transition, "CSSTransition", "A CSSTransition is running");
+
+    transition.pause();
+    assert_equals(getComputedStyle(target).getPropertyValue(customProperty), options.expected, "Element has the expected animated value");
+
+    await transitionEventPromise;
+  }, description);
+}
+
+function no_transition_test(options, description) {
+  test(() => {
+    const customProperty = generate_name();
+
+    CSS.registerProperty({
+      name: customProperty,
+      syntax: options.syntax,
+      inherits: false,
+      initialValue: options.from
+    });
+
+    assert_equals(getComputedStyle(target).getPropertyValue(customProperty), options.from, "Element has the expected initial value");
+
+    target.style.transition = `${customProperty} 1s -500ms linear`;
+    target.style.setProperty(customProperty, options.to);
+
+    assert_equals(target.getAnimations().length, 0, "No animation was created");
+    assert_equals(getComputedStyle(target).getPropertyValue(customProperty), options.to, "Element has the expected final value");
+  }, description);
+};