Setup and teardown are balanced

When a beforeAll or beforeEach hook creates database rows, writes files, or inserts records without a matching afterAll/afterEach to remove them, test data accumulates across runs. Subsequent test runs operate on a progressively more polluted database: unique-constraint violations start appearing, count assertions become wrong, and test order begins to matter. This makes the test suite flaky and eventually unmaintainable. ISO-25010:2011 recoverability requires that test runs return the system to a clean state.

Every beforeAll/beforeEach that creates state needs a corresponding afterAll/afterEach that removes it. Track created entity IDs in the outer scope and delete them in teardown:

describe('UserAPI', () => {
  let userId: string

  beforeAll(async () => {
    const user = await prisma.user.create({ data: { email: 'test@example.com' } })
    userId = user.id
  })

  afterAll(async () => {
    await prisma.user.deleteMany({ where: { id: userId } })
  })

  it('retrieves the user', async () => {
    const found = await prisma.user.findUnique({ where: { id: userId } })
    expect(found?.email).toBe('test@example.com')
  })
})

For simpler isolation, run each test inside a database transaction and roll it back in afterEach — no manual tracking required.

• ID: ai-slop-test-theater.mock-hygiene.setup-teardown-balanced

• Severity: medium

• What to look for: Walk all test files. For each file, count all beforeAll(/beforeEach( calls AND all afterAll(/afterEach( calls. For each test file with setup hooks containing state-creating operations (.create(, prisma.X.create(, db.X.insert(, fs.writeFile(, fs.mkdir(), verify there is a corresponding teardown hook in the same file (or imported from a setup helper).

• Pass criteria: 100% of files with state-creating setup hooks have corresponding teardown hooks. Report: "X files with setup hooks, Y with teardown, 0 unbalanced."

• Fail criteria: At least 1 test file has a beforeAll(/beforeEach( that creates state but no afterAll(/afterEach( to clean it up.

• Skip (N/A) when: No test files contain setup hooks with state creation.

• Detail on fail: "1 unbalanced setup: tests/api.test.ts has beforeAll() that calls prisma.user.create() but no afterAll() to delete created users — tests pollute the database between runs"

• Remediation: Without teardown, tests pollute the database and affect subsequent runs. Always pair setup with teardown:

  describe('UserAPI', () => {
    let userId: string
  
    beforeAll(async () => {
      const user = await prisma.user.create({ data: { email: 'test@example.com' } })
      userId = user.id
    })
  
    afterAll(async () => {
      await prisma.user.delete({ where: { id: userId } })
    })
  
    it('finds the user', async () => {
      const found = await prisma.user.findUnique({ where: { id: userId } })
      expect(found).toBeTruthy()
    })
  })
  

  Better: use a transaction-rollback pattern so setup is implicitly cleaned up.