Unit test coverage above 60%

Having test files is necessary but not sufficient — a test suite that only renders components without crashing and ignores business logic in src/lib/ provides false confidence. ISO 25010:2011 §6.5.5 requires that reliability verification covers the critical paths. A payment calculation function, a permission check, or a data transformation that is never tested will eventually receive a change that breaks it; without a coverage gate, no one learns about it until a user reports a wrong order total or a privilege escalation.

Prioritize business logic over UI rendering — pure functions in src/lib/, src/utils/, and src/services/ are the highest-return coverage targets. Enforce a minimum in your test config:

// vitest.config.ts
import { defineConfig } from 'vitest/config'
export default defineConfig({
  test: {
    coverage: {
      provider: 'v8',
      thresholds: {
        lines: 60,
        functions: 60,
        branches: 50,
      },
      exclude: ['**/*.config.*', 'src/app/**', 'src/components/**'],
    },
  },
})

Run npx vitest run --coverage to see your current baseline before writing new tests.