test(integration-karma): add tests for objects with computed key

packages/@lwc/integration-karma/test/lwc-on/index.spec.js

@@ -8,8 +8,7 @@ import Lifecycle from 'x/lifecycle';
 import Rerender from 'x/rerender';
 import RerenderLoop from 'x/rerenderLoop';
 import PublicProp from 'x/publicProp';
-
-// import { catchUnhandledRejectionsAndErrors, spyConsole } from 'test-utils';
+import ComputedKey from 'x/computedKey';
 
 describe('lwc:on', () => {
     it('adds multiple event listeners', () => {
@@ -346,4 +345,15 @@ describe('lwc:on', () => {
         button.click();
         expect(testFn).toHaveBeenCalled();
     });
+
+    it('works properly with objects whose keys are computed', () => {
+        const element = createElement('x-computed-key', { is: ComputedKey });
+        const testFn = jasmine.createSpy('test function');
+        element.testFn = testFn;
+        document.body.appendChild(element);
+        const button = element.shadowRoot.querySelector('button');
+
+        button.click();
+        expect(testFn).toHaveBeenCalled();
+    });
 });

packages/@lwc/integration-karma/test/lwc-on/x/computedKey/computedKey.html

@@ -0,0 +1,3 @@
+<template>
+    <button lwc:on={eventHandlers}>Click Me</button>
+</template> 

packages/@lwc/integration-karma/test/lwc-on/x/computedKey/computedKey.js

@@ -0,0 +1,20 @@
+import { LightningElement, api } from 'lwc';
+
+let testFn;
+const mouseover = 'click';
+
+export default class ComputedKey extends LightningElement {
+    @api
+    get testFn() {
+        return testFn;
+    }
+    set testFn(val) {
+        testFn = val;
+    }
+
+    eventHandlers = {
+        [mouseover]: function () {
+            testFn();
+        },
+    };
+}