component-fixtures

Create a file ending in .fixture.ts under src/vs/workbench/test/browser/componentFixtures/ that exports a default defineThemedFixtureGroup. Each fixture uses defineComponentFixture with a render function that builds the widget inside the provided container.

Use createEditorServices to get a TestInstantiationService with base editor services pre-registered, then register additional services via the additionalServices callback. Create mock instances with the mock<T>() helper from base/test/common/mock.js and register them with reg.defineInstance.

Flickering usually comes from reparenting DOM elements after async waits, which invalidates absolute positioning and triggers focus loss. Render the widget in-place with the correct DOM structure from the start instead of moving it between parents.

Fixtures render inside shadow DOM, so CSS rules scoped to deep ancestor selectors like .workbench .sidebar .my-view will not match. Recreate the expected ancestor class structure in the fixture, or refactor the component CSS to use self-contained selectors.

Yes, pass pre-filled data through the constructor or options to initialize the component directly into the completed state. For example, set isUsed: true and provide answer data on a question carousel model rather than simulating the full interaction flow.