Duplicate writes on retry with testRetries configuration

Question

Cypress testRetries re-executes the whole test including before and beforeEach hooks when a run fails. The documented behavior means any real side-effecting operation performed during the attempt, such as a UI form submission or cy.request POST, can be executed again on retry.

Cypress clears cookies and local storage between attempts but does not roll back server-side state. That leaves an unresolved design decision for write-heavy specs about how to keep retries safe without accepting duplicate records or reducing end-to-end fidelity.

What boundary should govern the use of testRetries with real backend writes versus stubbed network calls? Should specs that create persistent records be excluded from retries or require backend test hooks for idempotent setup and teardown? How does session reset between retry attempts interact with beforeEach creation logic?

Tasadduq Burney · Answer

To prevent duplicate writes during Cypress retries, you must ensure your backend operations are idempotent or stub the network layer for non-critical tests.Because Cypress re-executes the entire test lifecycle—including all before and beforeEach hooks—any side-effecting operation that occurs before a failure will be repeated. While Cypress automatically clears client-side state like cookies and local storage, it has no control over server-side database changes.
The Boundary for Retries
p>The decision to use testRetries with real writes versus stubs should depend on the goal of the test:

Stubbed Calls: Use these for UI/UX testing where the focus is on the frontend reaction to data rather than the data itself. This eliminates duplicate records entirely and speeds up execution.
Idempotent Real Writes: Use these for critical E2E flows. If your backend handles duplicate requests (e.g., using unique client-side keys or UUIDs), retries can be used without side effects.
Excluded from Retries: Specs that perform complex stateful mutations that cannot be easily rolled back should have retries disabled at the file level using { retries: 0 }.

Session and Hook Interaction
When a retry occurs, the beforeEach hook runs again. If this hook creates a user or a record, the second attempt will attempt to create that same record once more. To manage this, consider these strategies:

Check-before-create: Modify your hooks to check for the existence of a record before attempting to create it.
Unique Test Data: Generate unique identifiers for each test run so the backend can recognize and ignore duplicate submissions of the same entity.
Backend Hooks: Use a dedicated test API to reset the specific data state before each test attempt, ensuring a clean slate for every retry.

Diagnostic Question: Are your duplicate records occurring during the beforeEach setup phase or within the main body of the test itself?

Duplicate writes on retry with testRetries configuration

1 answer

To prevent duplicate writes during Cypress retries, you must ensure your backend operations are idempotent or stub the network layer for non-critical tests.

The Boundary for Retries

Session and Hook Interaction

Your perspective belongs here.

0 question comments