Ask Claude to Find Inconsistencies Between Related Files That Should Match

Code that should be consistent across files often isn't — a column was added to the migration but not the model's fillable array, or the frontend form sends fields the API doesn't accept. Claude reads both sides and finds the gaps.

"Check that the User model matches its migration — fillable fields, casts, 
relationships, and any columns that exist in the database but aren't in the model"

Claude compares the migration, model, factory, and tests, then flags every inconsistency — a column with no cast, a relationship with no foreign key, or a factory that creates data the validation would reject.

This works for any pair of files that should agree:

# Frontend forms vs API validation
"Check that the registration form sends exactly the fields the 
RegisterController validates — no missing fields, no extra ones"

# TypeScript types vs API responses
"Compare the TypeScript User interface with the UserResource — 
find fields that exist in one but not the other"

# Config references vs actual config
"Check that every config key referenced in the code actually exists 
in the config files"

# Route names vs usage
"Find route names used in the code that don't exist in the routes 
file, and routes defined but never referenced"

# Test data vs validation rules
"Check that the test factories create data that passes the 
validation rules — find any factory values that would fail validation"

Claude catches drift that's invisible to linters:

• Schema drift — migration adds a column, model doesn't know about it
• API contract drift — backend changed a response field, frontend still expects the old name
• Validation drift — form request has rules for fields that were removed from the form
• Test drift — tests assert old behavior after a refactor changed the expected output
• Config drift — code references config keys that were renamed or removed

Inconsistencies between related files are the hardest bugs to find because each file looks correct in isolation — Claude reads them together and spots what doesn't match.

via Claude Code