jest obsolete snapshots: how to clean up

TL;DR

Obsolete snapshots are snapshots no test uses anymore. Remove them with jest --ci=false -u after verifying they are truly obsolete, and review the diff before committing.

Error

Snapshot summary: 12 obsolete snapshots found, 0 written, 0 updated.

Steps

1. Run the full suite to see which snapshots are obsolete. Expected: the summary lists them.
2. Check that the tests which used them were intentionally deleted or changed. Expected: no surprise deletions.
3. Remove with npx jest -u. Expected: obsolete snapshots are deleted, live ones updated only if changed.
4. Review the snapshot diff in git. Expected: only obsolete entries removed.
5. Commit the cleaned snapshot file. Expected: the suite is green and the file is smaller.

When to use

• obsolete in the snapshot summary after a refactor.
• Snapshot files growing without bound.

When not to use

• Snapshots mismatch on values (decide update vs app fix first).
• You want to delete snapshots to make failures go away (that deletes coverage).

Tool compatibility

• Jest 27 through 30; -u / --updateSnapshot.

Variant phrasings

Jest remove unused snapshots

The same task; -u is the mechanism.

Snapshot obsolete after component refactor

The common trigger; verify intent before deleting.

Why it happens

Snapshots persist in the file even after their test is deleted or renamed. They accumulate silently.

Edge cases

• --ci mode fails on obsolete snapshots instead of cleaning; run cleanup locally, not in CI.
• Renamed tests orphan their snapshots; the summary flags them as obsolete.
• Review the diff: -u also updates changed snapshots, which may mask real changes.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_FurNNzJ5ESuOzWJlgwgNKg