testing

@anexileddev

Provides testing patterns for FastAPI endpoints and Svelte 5 components using pytest and Vitest. USE WHEN the user asks to "write tests for a FastAPI endpoint", "test a Svelte component", "set up pytest fixtures", "configure Vitest for SvelteKit", "mock dependencies in tests", "test SSE streaming endpoints", or works with pytest, httpx AsyncClient, Vitest, @testing-library/svelte, MSW, pytest-anyio. DO NOT USE for general testing theory unrelated to FastAPI or Svelte.