Ask Claude to Rename a Variable, Function, or Class Across the Entire Codebase

IDE rename tools miss things. They catch direct references but skip string mentions, config keys, route names, documentation, and dynamic calls. Claude finds all of them.

"Rename the UserManager class to UserService everywhere in the codebase"

Claude searches for every occurrence — class definitions, imports, type hints, container bindings, config references, test mocks, comments that mention it, and documentation that references it — then renames them all consistently.

This goes beyond find-and-replace:

# Rename a function and update all callers
"Rename getUserData to fetchUserProfile everywhere — update the function, 
all call sites, any tests that mock it, and the API documentation"

# Rename with convention changes
"Rename the 'active' scope to 'published' on the Post model — update the scope, 
every query that uses it, tests, and any comments that reference it"

# Rename a database column and everything that references it
"Rename the 'fname' column to 'first_name' — write the migration, update the model, 
update every query, form, validation rule, and API response that uses it"

# Rename a route and update all links
"Rename the 'user.settings' route to 'user.preferences' — update the route 
definition, every route() call, any redirects, and navigation links"

Claude handles the nuances that simple search-and-replace can't:

• Case variations — renames user_manager, UserManager, userManager, and USER_MANAGER appropriately
• Partial matches — knows that renaming User shouldn't rename UserService or getCurrentUser
• Dynamic references — finds string-based lookups like app('user.manager') or config('services.user_manager')
• Test assertions — updates assertion messages and mock expectations, not just the code under test
• Related names — asks if you also want to rename related things (e.g., the database table, the migration, the factory)

After the rename, run your tests to verify nothing was missed:

"Now run the tests to make sure the rename didn't break anything"

A bad name is a bug that compounds over time — let Claude do the rename properly so you stop working around it.

via Claude Code