Bug 1087872 - Tests for dynamic change of ruby frames. r=bz,dbaron

layout/reftests/css-ruby/dynamic-insertion.js

@@ -0,0 +1,42 @@
+window.onload = function() {
+  // Force a reflow before any changes.
+  document.body.clientWidth;
+
+  var elems = document.querySelectorAll('[data-insert]');
+  Array.from(elems).forEach(function(e) {
+    var parent, ref;
+    switch (e.dataset.insert) {
+      case 'start':
+        parent = e;
+        ref = e.firstChild;
+        break;
+
+      case 'end':
+        parent = e;
+        ref = null;
+        break;
+
+      case 'before':
+        parent = e.parentNode;
+        ref = e;
+        break;
+
+      case 'after':
+        parent = e.parentNode;
+        ref = e.nextSibling;
+        break;
+    }
+
+    var elem, textnode;
+    if ('text' in e.dataset) {
+      textnode = document.createTextNode(e.dataset.text);
+    }
+    if ('tag' in e.dataset) {
+      elem = document.createElement(e.dataset.tag);
+      if (textnode) {
+        elem.appendChild(textnode);
+      }
+    }
+    parent.insertBefore(elem ? elem : textnode, ref);
+  });
+};