The gaps in your test suite that let bugs escape
The happy path is tested, but what about nulls, empty arrays, and boundary conditions?
Tests that pass sometimes and fail others — the silent killers of CI/CD confidence
Tests that depend on each other or share mutable state — debugging nightmares
From unit tests to E2E, Test Analyst reviews them all
Function and class level testing
Component interaction testing
End-to-end user flow testing
Endpoint and contract testing
UI regression detection
Load and benchmark testing
Real examples of test improvements
describe('calculateDiscount', () => {
it('applies 10% for orders over $100', () => {
expect(calculateDiscount(150)).toBe(15)
})
it('applies 5% for orders over $50', () => {
expect(calculateDiscount(75)).toBe(3.75)
})
// What about $0? Negative? Exactly $50? $100?
})Missing boundary tests: $0, $50, $100, negative
describe('calculateDiscount', () => {
it('applies 10% for orders over $100', () => {
expect(calculateDiscount(150)).toBe(15)
})
it('applies 5% for orders over $50', () => {
expect(calculateDiscount(75)).toBe(3.75)
})
it('returns 0 for orders at boundary', () => {
expect(calculateDiscount(50)).toBe(0)
expect(calculateDiscount(100)).toBe(5) // 5% tier
})
it('handles zero and negative gracefully', () => {
expect(calculateDiscount(0)).toBe(0)
expect(calculateDiscount(-10)).toBe(0)
})
})Add edge cases for boundaries and invalid inputs
it('shows notification after save', async () => {
await user.click(saveButton)
// Flaky! Depends on timing
await waitFor(() => {
expect(screen.getByText('Saved!')).toBeVisible()
})
// Even worse: arbitrary timeout
await new Promise(r => setTimeout(r, 100))
expect(notificationCount).toBe(1)
})Arbitrary timeouts and timing assumptions
it('shows notification after save', async () => {
await user.click(saveButton)
// Wait for specific state change
await waitFor(() => {
expect(screen.getByRole('alert')).toHaveTextContent('Saved!')
})
// Assert on observable behavior, not timing
expect(
await screen.findByRole('alert', { name: /saved/i })
).toBeVisible()
})Wait for observable state changes, not time
let testUser: User
beforeAll(async () => {
// Shared across ALL tests — mutations leak!
testUser = await createUser({ name: 'Test' })
})
it('updates user name', async () => {
await updateUser(testUser.id, { name: 'Updated' })
// Now testUser.name is 'Updated' for all following tests
})
it('checks original name', () => {
// FAILS! Previous test mutated shared state
expect(testUser.name).toBe('Test')
})Shared state in beforeAll leaks between tests
describe('user updates', () => {
let testUser: User
beforeEach(async () => {
// Fresh user for EACH test
testUser = await createUser({ name: 'Test' })
})
afterEach(async () => {
await deleteUser(testUser.id)
})
it('updates user name', async () => {
await updateUser(testUser.id, { name: 'Updated' })
expect(testUser.name).toBe('Updated')
})
it('checks original name', () => {
// Works! Fresh testUser with original name
expect(testUser.name).toBe('Test')
})
})Use beforeEach for test isolation
Test Analyst doesn't just count tests — it analyzes what they actually test. It finds the gaps between what your tests cover and what your code needs.
Maps code paths to find untested branches
Identifies timing and order dependencies
Recommends specific test cases to add
Analyze Test Coverage
Maps which code paths are tested and which aren't
Identify Weak Spots
Finds edge cases and error conditions without tests
Detect Anti-patterns
Spots flaky patterns and isolation issues
Suggest Improvements
Recommends specific test cases to add
Bad tests are worse than no tests — they give false confidence
Tests that cover edge cases catch bugs before users do
No more "retry until green" — tests pass or fail for real reasons
Good tests let you change code with confidence
100% coverage means nothing if tests don't catch bugs.
Test Analyst ensures your tests actually work.
Let Test Analyst find the gaps in your test suite. Free for 14 days, no credit card required.