component-fixtures

Isolated UI fixtures for screenshot testing are created by structuring fixture files with shadow DOM-safe CSS and mockable dependencies, allowing components to render deterministically without the full application shell for consistent visual regression coverage.

Component fixtures are isolated rendering environments needed for visual regression testing when you want to preview and screenshot UI elements independently, requiring service injection and mockable dependencies to avoid flaky renders caused by the full application shell.

Screenshot testing works with shadow DOM components in VS Code by applying shadow DOM-safe CSS within themed fixture rendering, providing the necessary editor and workbench services to complex components for deterministic visual captures.

To render Dark and Light themed variants for component screenshot testing, use a service-aware fixture setup that automatically builds theme variants, allowing side-by-side visual state comparison and reliable visual regression coverage across themes.

UI component screenshots look flaky or incomplete during visual regression testing when components lack mockable dependencies and service-aware setup; isolating components in fixtures with shadow DOM-safe CSS prevents incomplete renders caused by missing workbench services.