gen-test

Generate a Vitest test file for the specified source file. The test file must be co-located with the source file (e.g., foo.ts -> foo.test.ts).

Arguments

The user will provide a file path or describe the module to test.

Component tests (anything that renders JSX)

• The very first line must be // @vitest-environment jsdom — no blank lines above it
• Use @testing-library/react for rendering and querying (render, screen)
• Use @testing-library/jest-dom matchers (e.g., toHaveTextContent, toBeInTheDocument)
• Query by accessible roles (getByRole, getByLabelText) rather than test IDs
• Next.js pages/layouts use export default — import accordingly

Example shape:

// @vitest-environment jsdom
import { render, screen } from '@testing-library/react'
import MyPage from './page'

describe(`MyPage`, () => {
  it(`should render the heading`, () => {
    render(<MyPage />)
    expect(screen.getByRole(`heading`)).toHaveTextContent(`Expected text`)
  })
})

API route tests (anything under src/app/api/)

• Do NOT add the jsdom pragma
• Call route handler functions (GET, POST, etc.) directly — they return a standard Response
• Use the Drizzle db instance directly for database assertions
• Clean up database state in beforeEach
• Use @/db and @/const/... path aliases for imports

Example shape:

import { db } from '@/db'
import { myTable } from '@/db/schema'
import { GET } from './route'

beforeEach(async () => {
  await db.delete(myTable)
})

describe(`/api/my-endpoint`, () => {
  it(`should return success`, async () => {
    const response = await GET()

    expect(response.status).toBe(200)
    expect(await response.json()).toEqual({ success: true })
  })
})

General conventions

• Use backtick strings for describe and it labels (not single/double quotes)
• Follow AAA pattern: Arrange, Act, Assert (with blank lines separating each phase when all three are present)
• Use descriptive test names: it('returns 404 when resource not found')
• Named exports only — no default exports (except Next.js page/layout components)
• One describe block per logical unit; nest when testing sub-behaviors