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How to Refactor Across Your Whole Codebase in Cursor

Use codebase-wide context and Composer to apply a structural refactor that spans many files at once.

10 minAdvanced

Some refactors are too large to scope file by file: replacing a logging call everywhere, switching a date library, moving a util to a new location. Cursor can index your whole codebase and let Composer reason across it. This guide walks through a real refactor, replacing scattered console.log calls with a structured logger, while keeping the change safe to review.

A project indexed by Cursor (indexing runs automatically on open)
A clear before and after state for the refactor
A passing test suite or type checker to verify against

Confirm the codebase is indexed

Cursor builds a searchable index of your project so it can find references on its own. Check the indexing status in settings. A complete index means Composer can locate every call site without you listing files.

Scope the refactor with @codebase

In Composer, reference @codebase and describe the full transformation. Tell it the new pattern and ask it to find every occurrence of the old one. Being explicit about the import path of the new helper prevents wrong guesses.

Composer prompt

@codebase Replace every console.log call with logger.info from
src/lib/logger.ts. Add the import where missing. Leave console.error
calls untouched. List the files you changed when you finish.

Composer - Multi-file refactor

Explorer

checkout.ts

auth.ts

cart.ts

api.ts

src/checkout.ts

1+ import { logger } from './lib/logger';

3 function pay(order) {

4- console.log('charging', order.id);

5+ logger.info('charging', { orderId: order.id });

6 }

Composer groups the diff by file so you can step through each one.

Review file by file

Large refactors are where mistakes hide. Step through each file in the diff. Watch for the edge cases you flagged, such as console.error being left alone, and reject any file where the change looks wrong.

Run the checks

zsh - verify the refactor

$npm run typecheck

No errors found.

$npm test

Tests: 88 passed

$git grep -n 'console.log' src | wc -l

Refactor on a branch

Create a dedicated branch before a large automated refactor. If the diff is wrong, you can reset cleanly without untangling it from other work.

Result: every console.log across the codebase becomes a structured logger call with the right import added, verified by the type checker, tests, and a grep that returns zero remaining matches.