test: 💍 fix test by stubbing writeText

The hds copy button uses the browser clipboard api. The writeText
api can fail if the window is not active. This does not happen in
practice because the window has to be active to be clicked by the
user. But in tests with synthetic triggers this can fail.

Stubbing the writeText method is also how hds tests their
component:
https://github.com/hashicorp/design-system/blob/990981b5741f9a6bf28d100c330b7865ba74e506/showcase/tests/integration/components/hds/copy/button/index-test.gts#L20

Author: hashicc

addons/rose/package.json

@@ -86,6 +86,7 @@
     "prettier": "^3.3.3",
     "qunit": "^2.22.0",
     "qunit-dom": "^3.2.1",
+    "sinon": "^19.0.2",
     "stylelint": "^15.11.0",
     "stylelint-config-prettier-scss": "^0.0.1",
     "stylelint-config-standard-scss": "^11.0.0",

addons/rose/tests/integration/components/rose/code-editor/toolbar-test.js

@@ -7,6 +7,7 @@ import { module, test } from 'qunit';
 import { setupRenderingTest } from 'ember-qunit';
 import { click, render } from '@ember/test-helpers';
 import { hbs } from 'ember-cli-htmlbars';
+import sinon from 'sinon';
 
 module('Integration | Component | rose/code-editor/toolbar', function (hooks) {
   setupRenderingTest(hooks);
@@ -43,6 +44,9 @@ module('Integration | Component | rose/code-editor/toolbar', function (hooks) {
   });
 
   test('it calls onCopy callback', async function (assert) {
+    // `writeText` could fail if the document is not in focus which is common during test runs
+    sinon.stub(window.navigator.clipboard, 'writeText').resolves();
+
     const onCopy = () => {
       this.set('called', true);
     };
@@ -53,8 +57,9 @@ module('Integration | Component | rose/code-editor/toolbar', function (hooks) {
     assert.dom(toolbarSelector).isVisible();
     assert.dom(copyButtonSelector).isVisible();
     assert.dom(menuDividerSelector).doesNotExist();
-
     await click(copyButtonSelector);
     assert.true(this.called);
+
+    sinon.restore();
   });
 });