Allow target to be mocked in sendEvent

src/support/sendEvent.ts

@@ -133,6 +133,14 @@ export default function sendEvent<I extends EventInit>(target: Element, type: st
 		(event as CustomEvent).initCustomEvent(type, bubbles!, cancelable!, {});
 	}
 	try {
+		if ('target' in initProps) {
+			Object.defineProperty(event, 'target', {
+				value: (<any> initProps).target,
+				writable: false,
+				enumerable: true,
+				configurable: false
+			});
+		}
 		deepAssign(event, initProps);
 	}
 	catch (e) { /* swallowing assignment errors when trying to overwrite native event properties */ }

tests/unit/support/sendEvent.ts

@@ -57,6 +57,30 @@ registerSuite({
 		});
 	},
 
+	'mock target'() {
+		const target = document.createElement('div');
+		document.body.appendChild(target);
+
+		const mockTarget = {} as HTMLDivElement;
+		let called = false;
+
+		function listener(evt: CustomEvent) {
+			assert.strictEqual(evt.target, mockTarget, 'Target of event should be mock target');
+			called = true;
+		}
+
+		target.addEventListener('click', listener);
+
+		sendEvent(target, 'click', {
+			eventInit: {
+				target: mockTarget
+			}
+		});
+		assert.isTrue(called, 'listener should have been called');
+
+		document.body.removeChild(target);
+	},
+
 	'MouseEvents'() {
 		const target = document.createElement('button');
 		document.body.appendChild(target);