[BUGFIX beta] fix mouseEnter/Leave event delegation w/o jQuery for SVG & IE11

packages/@ember/-internals/glimmer/tests/integration/event-dispatcher-test.js

@@ -202,6 +202,62 @@ moduleFor(
       assert.strictEqual(receivedLeaveEvents[0].target, outer);
     }
 
+    ['@test delegated event listeners work for mouseEnter on SVG elements'](assert) {
+      let receivedEnterEvents = [];
+      let receivedLeaveEvents = [];
+
+      this.registerComponent('x-foo', {
+        ComponentClass: Component.extend({
+          tagName: 'svg',
+          mouseEnter(event) {
+            receivedEnterEvents.push(event);
+          },
+          mouseLeave(event) {
+            receivedLeaveEvents.push(event);
+          },
+        }),
+        template: `<g id="inner"></g>`,
+      });
+
+      this.render(`{{x-foo id="outer"}}`);
+
+      let parent = this.element;
+      let outer = this.$('#outer')[0];
+      let inner = this.$('#inner')[0];
+
+      // mouse moves over #outer
+      this.runTask(() => {
+        this.$(outer).trigger('mouseenter', { canBubble: false, relatedTarget: parent });
+        this.$(outer).trigger('mouseover', { relatedTarget: parent });
+        this.$(parent).trigger('mouseout', { relatedTarget: outer });
+      });
+      assert.equal(receivedEnterEvents.length, 1, 'mouseenter event was triggered');
+      assert.strictEqual(receivedEnterEvents[0].target, outer);
+
+      // mouse moves over #inner
+      this.runTask(() => {
+        this.$(inner).trigger('mouseover', { relatedTarget: outer });
+        this.$(outer).trigger('mouseout', { relatedTarget: inner });
+      });
+      assert.equal(receivedEnterEvents.length, 1, 'mouseenter event was not triggered again');
+
+      // mouse moves out of #inner
+      this.runTask(() => {
+        this.$(inner).trigger('mouseout', { relatedTarget: outer });
+        this.$(outer).trigger('mouseover', { relatedTarget: inner });
+      });
+      assert.equal(receivedLeaveEvents.length, 0, 'mouseleave event was not triggered');
+
+      // mouse moves out of #outer
+      this.runTask(() => {
+        this.$(outer).trigger('mouseleave', { canBubble: false, relatedTarget: parent });
+        this.$(outer).trigger('mouseout', { relatedTarget: parent });
+        this.$(parent).trigger('mouseover', { relatedTarget: outer });
+      });
+      assert.equal(receivedLeaveEvents.length, 1, 'mouseleave event was triggered');
+      assert.strictEqual(receivedLeaveEvents[0].target, outer);
+    }
+
     ['@test delegated event listeners work for mouseEnter/Leave with skipped events'](assert) {
       let receivedEnterEvents = [];
       let receivedLeaveEvents = [];

packages/@ember/-internals/views/lib/system/event_dispatcher.js

@@ -7,6 +7,7 @@ import jQuery, { jQueryDisabled } from './jquery';
 import ActionManager from './action_manager';
 import fallbackViewRegistry from '../compat/fallback-view-registry';
 import addJQueryEventDeprecation from './jquery_event_deprecation';
+import { contains } from './utils';
 
 /**
 @module ember
@@ -335,7 +336,7 @@ export default EmberObject.extend({
           while (
             target &&
             target.nodeType === 1 &&
-            (!related || (related !== target && !target.contains(related)))
+            (related === null || (related !== target && !contains(target, related)))
           ) {
             // mouseEnter/Leave don't bubble, so there is no logic to prevent it as with other events
             if (viewRegistry[target.id]) {

packages/@ember/-internals/views/lib/system/utils.js

@@ -199,3 +199,15 @@ export const elMatches =
 export function matches(el, selector) {
   return elMatches.call(el, selector);
 }
+
+export function contains(a, b) {
+  if (a.contains !== undefined) {
+    return a.contains(b);
+  }
+  while ((b = b.parentNode)) {
+    if (b === a) {
+      return true;
+    }
+  }
+  return false;
+}