Cypress Server process memory between spec files remains unresolved in Cypress 14

Answer

As of Cypress 14 there is no automatic garbage‑collection or process recycling for the Cypress Server between spec files. The server remains a single long‑lived Node process for the entire cypress run invocation, and no configuration flag currently triggers a restart between specs.

Likely explanation

The Cypress Server (the Node‑side process that drives the browser, handles commands, and, when using component testing, hosts the Vite dev server) is intentionally kept alive to avoid the overhead of spawning a new process for each spec. This design means that any retained references—such as custom command caches, Cypress aliases, Vite module graphs, WebSocket connections, or timers—can accumulate across specs, leading to the observed memory growth.

Confirmed facts

• Cypress 14 docs state that the experimental Server mode for component testing keeps the backend server alive across specs; there is no built‑in “reset server” option.
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• The Node 18+ requirement only ensures the server can use modern JavaScript features; it does not change the server’s lifecycle.
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• Configuration such as video, screenshotOnRunFailure, trashAssetsBeforeRuns, or clearCookies/clearLocalStorage affects browser‑side resources but does not force the Server process to restart.

Steps needed for this case

1. Isolate specs by process: run each spec in a separate Cypress invocation, e.g.

   for spec in cypress/e2e/**/*.cy.js; do
     npx cypress run --spec "$spec"
   done

   This guarantees a fresh Server process per spec.
2. Reduce per‑spec overhead: disable video and screenshots if they are not required (video: false, screenshotOnRunFailure: false) to lower baseline memory usage.
3. Clean Cypress state: after each spec (or in a afterEach hook) explicitly clear aliases and cached DOM references:

   afterEach(() => {
     // clear Cypress aliases
     Object.keys(this).forEach(k => delete this[k]);
     // optional: clear cookies/localStorage
     cy.clearCookies();
     cy.clearLocalStorage();
   });

4. Monitor memory: use OS tools (Task Manager, top, ps) or Chrome DevTools Memory tab to take heap snapshots before and after each spec; look for detached DOM nodes or lingering event listeners.

Missing diagnostic detail

To refine the recommendation, please confirm whether the memory growth is observed in end‑to‑end tests or in component testing (where the Server mode is active). The answer influences whether you need to focus on Vite dev‑server cleanup or primarily on browser‑side cleanup.