Change Range.getBoundingClientRect() when the first rect is empty

third_party/WebKit/LayoutTests/fast/dom/Range/get-bounding-client-rect-empty-and-non-empty.html

+<!DOCTPYE html>
+<script src="../../../resources/testharness.js"></script>
+<script src="../../../resources/testharnessreport.js"></script>
+<style>
+html, body {
+  margin: 0;
+}
+
+#container > div {
+  font-size: 10px;
+  width: 5ch;
+  border: thin solid black;
+}
+</style>
+<div id="log"></div>
+<div id="container">
+  <div title="normal wrap">0123 456</div>
+  <div title="normal wrap, space overflows">01234 567</div>
+  <div title="pre-wrap" style="white-space: pre-wrap">0123 45678</div>
+  <div title="pre-wrap, space overflows" style="white-space: pre-wrap">01234 5678</div>
+  <div title="break-word" style="word-wrap: break-word">0123456789</div>
+  <div title="pre" style="white-space:pre">a
+b<span></span>b</div>
+</div>
+<script>
+var range = document.createRange();
+
+Array.prototype.forEach.call(container.children, function (element) {

[eae, 2016/05/05 13:28:29]

Please don't do this. Data driven tests like this are very hard to debug and
reason about. 

Instead please explicitly assert the individual conditions you want to test.

[kojii, 2016/05/06 06:11:02]

Done, I'm not certain if I understand this correctly though, appreciate to tell
me so if I misunderstand.

+  var name = element.title;
+  var node = element.firstChild;
+  for (var i = 0; i < node.textContent.length; i++) {
+    range.setStart(node, i);
+    range.setEnd(node, i + 1);
+    var rects = range.getClientRects();
+    var bounds = range.getBoundingClientRect();
+    if (rects.length <= 1)
+      continue;
+    // If all rects are empty, bounds should be rects[0].
+    if (bounds.width == 0 || bounds.height == 0) {
+      test(function () {
+        assert_equals_rect(bounds, rects[0]);
+      }, name + "[" + i + "]isEmpty: " + rectToString(bounds) + " from " + rectsToString(rects));
+    }
+    test(function () {
+      assert_equals(bounds.height, rects[0].height);
+    }, name + "[" + i + "].height: " + rectToString(bounds) + " from " + rectsToString(rects));
+  }
+});
+
+function assert_equals_rect(actual, expected, description) {
+  for (var prop in expected)
+    assert_equals(actual[prop], expected[prop], description + "." + prop);
+}
+function rectsToString(rects) {
+  return "[" + Array.prototype.map.call(rects, rectToString).join() + "]";
+}
+
+function rectToString(r) {
+  return "(" + r.left + "," + r.top + "-" + r.width + "," + r.height + ")";
+}
+</script>