vitest-testinglisted

# Vitest Testing ## Running Tests ```bash # Run all tests npx vitest run # Run in watch mode npx vitest # Run with coverage npx vitest run --coverage # Run a specific test file npx vitest run src/utils/stats.test.ts # Run tests matching a pattern npx vitest run -t "rolling average" ``` ## Test File Naming - Unit tests: `<module>.test.ts` co-located with the source file - Integration tests: `<feature>.integration.test.ts` in a `__tests__/` directory ## Test Structure ```typescript import { describe, it, expect, beforeEach, vi } from 'vitest'; describe('ModuleName', () => { describe('functionName', () => { it('should describe expected behavior', () => { // Arrange const input = createTestInput(); // Act const result = functionName(input); // Assert expect(result).toEqual(expectedOutput); }); it('should handle edge case', () => { expect(() => functionName(null)).toThrow('Expected valid input'); }); }); }); ``` ## Best Practices - Test behavior, not implementation. If internal refactoring breaks tests, the tests are too coupled. - Use descriptive test names: `should calculate rolling AHI average with gaps in data` - Test edge cases: empty arrays, single elements, NaN values, boundary conditions. - Mock external dependencies (IndexedDB, OPFS, Web Workers) using `vi.mock()`. - Use `beforeEach` for setup, not shared mutable state. - For statistical functions, compare against known values from reference imp