pypi / syrupy

syrupy

What changed in syrupy 6, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-21.

3 breaking5 new APIs and options3 performance1 tooling3 fixes and other

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

syrupy 615 changes

The separate DataclassPlugin has been removed; remove its imports and plugin wiring because stdlib dataclasses are serialized natively by the Amber serializer.
6.0.0release notes
The JSON extension serializes dates as YYYY-MM-DD instead of repr strings, so existing JSON snapshots containing dates need updating.
6.0.0release notes
The Amber serializer now serializes stdlib dataclasses natively; without the former plugin, snapshots may change from repr-style strings to structured Amber form.
6.0.0release notes

Experimental opt-in for pytest-xdist that uses an exclusive file lock and atomic replace around amber writes to prevent workers from dropping snapshots.
6.1.1release notes
Sets the maximum wait for the snapshot file lock; defaults to 60s.
6.1.1release notes
Experimental option to write Amber snapshots in pytest collection/declaration order, including parametrize/ids order, instead of alphabetical snapshot name order.
6.0.0release notes
snapshot(diff=...) accepts an in-memory baseline object, so tests can diff against data without writing a separate base snapshot.
6.0.0release notes
Skips unused-snapshot discovery, reporting, and deletion, providing an escape hatch for very large Amber suites where unused detection dominates runtime.
6.0.0release notes

Single-file extensions write updates immediately instead of buffering large payloads until session end, improving memory use; multi-entry Amber files still batch writes.
6.0.0release notes
Under partial selection, unused detection considers only plausible test files, reducing its cost with sharding plugins such as pytest-split.
6.0.0release notes
Worker-to-controller snapshot collection payloads are compressed, cutting transfer size for large suites.
6.0.0release notes

Tests that use the snapshot fixture, directly or indirectly, are marked automatically, allowing snapshot updates to target only those tests.
6.0.0release notes

With regex=False, path_value now replaces values at nested paths such as user.token; previously, default-mode lookup missed escaped path keys.
6.0.0release notes
Sorting values such as homogeneous frozensets with partial ordering no longer depends on PYTHONHASHSEED, preventing flaky snapshots.
6.0.0release notes
Skipped sibling single-file snapshots are no longer reported as unused or deleted during --snapshot-update.
6.0.0release notes