IntersectionObserver: convert tests to testharness.js

third_party/WebKit/LayoutTests/intersection-observer/resources/intersection-observer-test-utils.js

+// Here's how waitForNotification works:
+//
+// - myTestFunction0()
+//   - waitForNotification(myTestFunction1)
+//     - requestAnimationFrame()
+//   - Modify DOM in a way that should trigger an IntersectionObserver callback.
+// - BeginFrame
+//   - requestAnimationFrame handler runs
+//     - First setTimeout()
+//   - Style, layout, paint
+//   - IntersectionObserver generates new notifications
+//     - Posts a task to deliver notifications
+// - First setTimeout handler runs
+//   - Second setTimeout()
+// - Task to deliver IntersectionObserver notifications runs
+//   - IntersectionObserver callbacks run
+// - Second setTimeout handler runs
+//   - myTestFunction1()
+//     - [optional] waitForNotification(myTestFunction2)
+//       - requestAnimationFrame()
+//     - Verify newly-arrived IntersectionObserver notifications
+//     - [optional] Modify DOM to trigger new notifications
+function waitForNotification(f) {
+  requestAnimationFrame(function() {
+    setTimeout(function() { setTimeout(f); });
+  });
+}
+
+// The timing of when runTestCycle is called is important.  It should be
+// called:
+//
+//   - Before or during the window load event, or
+//   - Inside of a prior runTestCycle callback, *before* any assert_* methods
+//     are called.
+//
+// Following these rules will ensure that the test suite will not abort before
+// all test steps have run.
+function runTestCycle(f, description) {
+  async_test(function(t) {
+    waitForNotification(t.step_func_done(f));
+  }, description);
+}
+
+// Root bounds for a root with an overflow clip as defined by:
+//   http://wicg.github.io/IntersectionObserver/#intersectionobserver-root-intersection-rectangle
+function contentBounds(root) {
+  var left = root.offsetLeft + root.clientLeft;
+  var right = left + root.clientWidth;
+  var top = root.offsetTop + root.clientTop;
+  var bottom = top + root.clientHeight;
+  return [left, right, top, bottom];
+}
+
+// Root bounds for a root without an overflow clip as defined by:
+//   http://wicg.github.io/IntersectionObserver/#intersectionobserver-root-intersection-rectangle
+function borderBoxBounds(root) {
+  var left = root.offsetLeft;
+  var right = left + root.offsetWidth;
+  var top = root.offsetTop;
+  var bottom = top + root.offsetHeight;
+  return [left, right, top, bottom];
+}
+
+function rectArea(rect) {
+  return (rect.left - rect.right) * (rect.bottom - rect.top);
+}
+
+function checkRect(actual, expected, description) {
+  if (!expected.length)
+    return;
+  assert_equals(actual.left, expected[0], description + '.left');
+  assert_equals(actual.right, expected[1], description + '.right');
+  assert_equals(actual.top, expected[2], description + '.top');
+  assert_equals(actual.bottom, expected[3], description + '.bottom');
+}
+
+function checkLastEntry(entries, i, expected) {
+  assert_equals(entries.length, i + 1, 'entries.length');
+  if (expected) {
+    checkRect(
+        entries[i].boundingClientRect, expected.slice(0, 4),
+        'entries[' + i + '].boundingClientRect');
+    checkRect(
+        entries[i].intersectionRect, expected.slice(4, 8),
+        'entries[' + i + '].intersectionRect');
+    checkRect(
+        entries[i].rootBounds, expected.slice(8, 12),
+        'entries[' + i + '].rootBounds');
+  }
+}
+
+function checkJsonEntry(actual, expected) {
+  checkRect(
+      actual.boundingClientRect, expected.boundingClientRect,
+      'entry.boundingClientRect');
+  checkRect(
+      actual.intersectionRect, expected.intersectionRect,
+      'entry.intersectionRect');
+  if (actual.rootBounds == 'null')
+    assert_equals(expected.rootBounds, 'null', 'rootBounds is null');
+  else
+    checkRect(actual.rootBounds, expected.rootBounds, 'entry.rootBounds');
+  assert_equals(actual.target, expected.target);
+}
+
+function checkJsonEntries(actual, expected, description) {
+  test(function() {
+    assert_equals(actual.length, expected.length);
+    for (var i = 0; i < actual.length; i++)
+      checkJsonEntry(actual[i], expected[i]);
+  }, description);
+}