Bug 1445934 [wpt PR 9919] - DOM: reset target/relatedTarget, a=testonly

Automatic update from web-platform-testsDOM: reset target/relatedTarget

For whatwg/dom#585.

wpt-commits: 2f758ac5c16e44915f270ceec31a84eed8f85769
wpt-pr: 9919
wpt-commits: 2f758ac5c16e44915f270ceec31a84eed8f85769
wpt-pr: 9919

testing/web-platform/meta/MANIFEST.json

@@ -321178,6 +321178,12 @@
      {}
     ]
    ],
+   "dom/events/relatedTarget.window.js": [
+    [
+     "/dom/events/relatedTarget.window.html",
+     {}
+    ]
+   ],
    "dom/historical.html": [
     [
      "/dom/historical.html",
@@ -546791,6 +546797,10 @@
    "40ab5636653dfd105738ab38e7d22316132eb630",
    "testharness"
   ],
+  "dom/events/relatedTarget.window.js": [
+   "0426d2ecae3f3562be175e4364353d979365ed1c",
+   "testharness"
+  ],
   "dom/historical.html": [
    "ccf3d9d2d8eb3e7353ecedd8a4d8ba232f9374ec",
    "testharness"

testing/web-platform/tests/dom/events/relatedTarget.window.js

@@ -0,0 +1,85 @@
+// https://dom.spec.whatwg.org/#concept-event-dispatch
+
+const host = document.createElement("div"),
+      child = host.appendChild(document.createElement("p")),
+      shadow = host.attachShadow({ mode: "closed" }),
+      slot = shadow.appendChild(document.createElement("slot"));
+
+test(() => {
+  for (target of [shadow, slot]) {
+    for (relatedTarget of [new XMLHttpRequest(), self, host]) {
+      const event = new FocusEvent("demo", { relatedTarget: relatedTarget });
+      target.dispatchEvent(event);
+      assert_equals(event.target, null);
+      assert_equals(event.relatedTarget, null);
+    }
+  }
+}, "Reset if target pointed to a shadow tree");
+
+test(() => {
+  for (relatedTarget of [shadow, slot]) {
+    for (target of [new XMLHttpRequest(), self, host]) {
+      const event = new FocusEvent("demo", { relatedTarget: relatedTarget });
+      target.dispatchEvent(event);
+      assert_equals(event.target, null);
+      assert_equals(event.relatedTarget, null);
+    }
+  }
+}, "Reset if relatedTarget pointed to a shadow tree");
+
+async_test(t => {
+  const shadowChild = shadow.appendChild(document.createElement("div"));
+  shadowChild.addEventListener("demo", t.step_func(() => document.body.appendChild(shadowChild)));
+  const event = new FocusEvent("demo", { relatedTarget: new XMLHttpRequest() });
+  shadowChild.dispatchEvent(event);
+  assert_equals(shadowChild.parentNode, document.body);
+  assert_equals(event.target, null);
+  assert_equals(event.relatedTarget, null);
+  shadowChild.remove();
+  t.done();
+}, "Reset if target pointed to a shadow tree pre-dispatch");
+
+async_test(t => {
+  const shadowChild = shadow.appendChild(document.createElement("div"));
+  shadowChild.addEventListener("demo", t.step_func(() => document.body.appendChild(shadowChild)));
+  const event = new FocusEvent("demo", { relatedTarget: shadowChild });
+  document.body.dispatchEvent(event);
+  assert_equals(shadowChild.parentNode, document.body);
+  assert_equals(event.target, null);
+  assert_equals(event.relatedTarget, null);
+  shadowChild.remove();
+  t.done();
+}, "Reset if relatedTarget pointed to a shadow tree pre-dispatch");
+
+async_test(t => {
+  const event = new FocusEvent("heya", { relatedTarget: shadow, cancelable: true }),
+        callback = t.unreached_func();
+  host.addEventListener("heya", callback);
+  t.add_cleanup(() => host.removeEventListener("heya", callback));
+  event.preventDefault();
+  assert_true(event.defaultPrevented);
+  assert_false(host.dispatchEvent(event));
+  assert_equals(event.target, null);
+  assert_equals(event.relatedTarget, null);
+  // Check that the dispatch flag is cleared
+  event.initEvent("x");
+  assert_equals(event.type, "x");
+  t.done();
+}, "Reset targets on early return");
+
+async_test(t => {
+  const input = document.body.appendChild(document.createElement("input")),
+        event = new MouseEvent("click", { relatedTarget: shadow });
+  let seen = false;
+  t.add_cleanup(() => input.remove());
+  input.type = "checkbox";
+  input.oninput = t.step_func(() => {
+    assert_equals(event.target, null);
+    assert_equals(event.relatedTarget, null);
+    assert_equals(event.composedPath().length, 0);
+    seen = true;
+  });
+  assert_true(input.dispatchEvent(event));
+  assert_true(seen);
+  t.done();
+}, "Reset targets before activation behavior");