File snapshots

Snapshots can be stored in files in the test/resources/snapshot directory.

assertFileSnapshot tests that a string matches the contents of a snapshot file.

To use a snapshot, pass in a relative path to assertFileSnapshot.

For example, to use a snapshot in test/resources/snapshot/config.json:

val found = """{"environment": "dev", "region": "us-east-2"}"""
assertFileSnapshot(found, "config.json")

New snapshots

You can create a new snapshot file by passing the relative path to assertFileSnapshot.

val found = """{"environment": "dev", "region": "us-east-2"}"""
assertFileSnapshot(found, "new-config.json")

Run your tests and promote your snapshots:

sbt test
sbt snapshot4sPromote

Your snapshot will be created in test/resources/snapshot/new-config.json:

The assertFileSnapshot assertion only supports strings.

If you'd like to test a non-String value, consider writing it in code using inline snapshots.