Testing a Property in a Lightning Web Component

Alain,
That is the same documentation I've been using. That is basically my Trial 2 approach, but document.body.appendChild(element) is before the element assignment. I tried it in that order as well, but it didn't work. The error I get back is the querySelector doesn't find the element. However, when I default the value in my code to true for showDesktopView (which I cannot leave it like that), the query selector does find the "Name" element it is looking for.

This is a closer representation of my code following what you suggested, but doens't work: it('Displays Contact Name field', () => { const element = createElement('c-test', { is: testLWC }); document.body.appendChild(element); element.showDesktopView = true; getRecordWireAdapter.emit(mockGetRecord); // Resolve a promise to wait for a rerender of the new content. return Promise.resolve().then(() => { const content = element.shadowRoot.querySelector('.myclass'); const nameField = mockGetRecord.fields.Name.value; console.log('Expected: ' + nameField) console.log('Found: ' + content.textContent); expect(content.textContent).toBe(nameField);
The error I get back is "TypeError: Cannot read property 'textContent' of null" which is recieved when the querySelector doesn't find the rendered element. Again, the test case does pass if I default the showDesktopView to true.