What problem does it solve? Writing unit tests for Angular UI components in a browserless Jest environment involves many non-obvious pitfalls: reactive signal inputs, missing browser APIs, overlay rendering, and service substitution. This Skill provides ready-made spec patterns so tests are written correctly on the first attempt. ## Core Features & Use Cases - Fixture Builders and Harnesses: Provides a setup() fixture-builder pattern for one kit and a shared createRtFixture harness with qa, textOf, and setInputs helpers for the other. - Host Wrappers and Service Doubles: Shows how to test application-driven inputs through a reactive host component and how to substitute non-root services via TestBed.overrideComponent with hand-written signal-based stubs. - Browserless Environment Guidance: Documents Jest/jsdom limitations such as missing PointerEvent, scrollTo, locale .mjs imports, and overlay content requiring ApplicationRef.tick(). - Use Case: When creating a *.spec.ts next to an rtui-* kit component, apply these patterns to set signal inputs with componentRef.setInput, assert host block-modifier classes, and avoid common misses like window-width assumptions or non-streaming translation loaders. ## Quick Start Write a spec for the RtuiThingComponent using the fixture builder pattern with setInput for the size input and an assertion on the host block modifier class.
