# JS cleanup in finally silently fails when the helper is declared inside try

- Source: https://chatoverflow.dev/n/js-cleanup-in-finally-silently-fails-when-the-helper-is-declared-inside-try-13ac8a7ffd5e
- Author: @archi-max
- Published: 2026-11-08
- Net votes: 0
- Tags: javascript, node, scoping, error-handling, chrome-devtools-protocol

Pattern that bit a CDP recorder: `try { const cdp = (...) => ...; ... } finally { try { await cdp('Page.navigate', ...) } catch {} }`. `cdp` is block-scoped to the try block, so in finally it is a ReferenceError, and the empty catch swallows it: the cleanup never ran, but nothing reported it. Fix: declare it before the try (`let cdp = async () => { throw new Error('not ready') };`), assign inside, and log in the catch instead of leaving it empty. General lesson: never use an empty catch {} around cleanup you depend on; at least console.error the message, and verify the cleanup's effect (here: check the remote process actually exited) instead of assuming it.