1 files changed, 47 insertions, 0 deletions
diff --git a/testing/web-platform/tests/html/semantics/selectors/pseudo-classes/dir-dynamic.html b/testing/web-platform/tests/html/semantics/selectors/pseudo-classes/dir-dynamic.html
new file mode 100644
index 0000000000..8f2951f8ef
--- /dev/null
+++ b/testing/web-platform/tests/html/semantics/selectors/pseudo-classes/dir-dynamic.html
@@ -0,0 +1,47 @@
+<!doctype html>
+<html>
+<head>
+  <meta charset="utf-8">
+  <script src="/resources/testharness.js"></script>
+  <script src="/resources/testharnessreport.js"></script>
+  <link rel="author" title="Vincent Hilla" href="mailto:vhilla@mozilla.com">
+  <link rel="help" href="https://html.spec.whatwg.org/#the-directionality">
+</head>
+<body>
+  <input id="inp"/>
+  <textarea id="ta"></textarea>
+  <div id="div"></div>
+  <pre id="pre"></pre>
+
+  <script>
+    function doTest(e) {
+      e.dir = "ltr";
+      assert_true(e.matches(":dir(ltr)"), "dir to ltr on " + e.tagName + " element");
+
+      e.dir = "rtl";
+      assert_true(e.matches(":dir(rtl)"), "dir to rtl on " + e.tagName + " element");
+
+      e.dir = "auto";
+      assert_true(e.matches(":dir(ltr)"), "dir to auto, empty text on " + e.tagName + " element");
+
+      e.value = "\u05D0;";
+      e.textContent = "\u05D0;";
+      assert_true(e.matches(":dir(rtl)"), "auto dir, text to Hebrew on " + e.tagName + " element");
+
+      e.dir = "ltr";
+      assert_true(e.matches(":dir(ltr)"), "dir to ltr, Hebrew text on " + e.tagName + " element");
+
+      e.dir = "auto";
+      assert_true(e.matches(":dir(rtl)"), "dir to auto, Hebrew text on " + e.tagName + " element");
+
+      e.removeAttribute("dir");
+      assert_true(e.matches(":dir(ltr)"), "dir removed, Hebrew text on " + e.tagName + " element");
+    }
+
+    const elements = [inp, ta, div, pre];
+    for (const e of elements) {
+      test(() => doTest(e), "Dynamically changing dir, text on " + e.tagName.toLowerCase() + " element");
+    }
+  </script>
+</body>
+</html>