Jest "obsolete snapshots" Fail CI with --ci - Stale .snap Entries

Renaming or deleting a test leaves its stored snapshot key orphaned in the .snap file. Locally Jest auto-prunes these, but with --ci it refuses to write - and a CI check that treats obsolete snapshots as a failure then breaks the build.

What this error means

CI reports "N obsolete snapshots found" after a green test run. The tests pass, but a strict snapshot gate (or --ci with a check) fails because stale .snap entries were never removed and committed.

Jest output

› 2 snapshots obsolete.
  ↳ src/__snapshots__/Card.test.tsx.snap
      • <Card /> renders old layout 1
      • <Card /> renders old layout 2

  (use --updateSnapshot / -u to remove them - not run with --ci)

Common causes

Snapshot keys orphaned by renamed/removed tests

A test was renamed or deleted, but its snapshot entry still lives in the .snap file. The key no longer maps to any test, so Jest flags it as obsolete.

--ci never auto-prunes

In --ci mode Jest will not rewrite .snap files, so obsolete entries are reported rather than cleaned. A gate that fails on obsolete snapshots then breaks CI.

How to fix it

Prune obsolete snapshots locally and commit

Terminal

jest -u            # removes obsolete snapshot keys locally
git add **/*.snap  # commit the pruned snapshots

Keep CI strict but clean

Run CI with --ci so missing/obsolete snapshots fail instead of silently writing.
After renaming a describe/test, re-run -u locally to drop the old keys.
Review .snap diffs in PRs so orphaned entries are caught before merge.

How to prevent it

Run jest -u after renaming or deleting snapshot tests.
Review snapshot file diffs in code review.
Keep CI on --ci so stale snapshots surface immediately.