Missing test fixture or seed data

What this failure means

A test failed because it could not load a required fixture file, seed record, or test helper resource that was expected to exist before the test ran.

Symptoms

Faultline looks for one or more of these log fragments:

fixture not found
missing fixture
fixture file missing
no such file or directory
FileNotFoundError
FactoryBot
factory_bot
factory not registered

Diagnosis

A test failed because it could not load a required fixture file, seed record, or test helper resource that was expected to exist before the test ran.

Fix steps

1. Run the database seed step before the test suite: rails db:seed, npm run db:seed, python manage.py loaddata, or the project equivalent.

2. Check if the fixture file was recently renamed or deleted:

   git log --diff-filter=D --name-only --pretty=format: -- testdata/ fixtures/ | grep -v "^$" | head -20
   

3. Verify the fixture path is committed and not gitignored:

   git ls-files testdata/
   git ls-files fixtures/
   

4. For factory errors: confirm the factory definition matches the current model schema. Run pending migrations before seeding: rails db:migrate, python manage.py migrate.

5. Update the fixture file or factory definition to match the current data model, then re-run migrations and seeds before the test suite.

Validation

• Run the seed step locally and confirm it exits 0.
• Re-run the full test suite and confirm the fixture-not-found errors are gone.

Why it matters

Fixture errors occur when a fixture file is deleted or renamed without updating the tests that reference it, when a database migration removes a field or table that fixtures depend on, or when a CI environment starts without running the required seed step.

Prevention

• Include fixture setup in a shared test setup script that runs automatically.
• Add a CI lint step that validates all referenced fixture files exist.
• When migrating, update all fixtures and factories in the same PR.
• Keep seed data, factories, and schema changes versioned together so test setup does not drift behind the application model.

Try it locally

git ls-files testdata/
git ls-files fixtures/
git ls-files testdata/

How Faultline detects it

Use faultline explain missing-test-fixture to see the full playbook.

faultline analyze build.log
faultline explain missing-test-fixture

Generated from playbooks/bundled/log/test/missing-test-fixture.yaml. Do not edit directly.