Snapshot testing fails on repeat running when using Swift Testing

[aim2120]

Describe the bug
When using Swift Testing with snapshot testing, running repeatedly (either in Xcode or with xcodebuild -test-iterations N) causes new snapshots to be recorded for each iteration, causing failures and excessive snapshots.

To Reproduce
See this repo: https://github.com/aim2120/SwiftSnapshotTestingRepeatRunningBug (instructions included in README)

Expected behavior
When running Swift Testing snapshot tests repeatedly, each iteration is able to succeed and the initial snapshot is used for each testing iteration comparison.

Environment

• swift-snapshot-testing version: 1.18.3 (latest)
• Xcode: 16.1
• Swift: 6.0
• OS: macOS 15.3.2

[jgallantgs]

We're experiencing a 60% increase in random snapshot exits since updating to 1.18.3. We've reverted to a previous version.

[mbrandonw]

Hi all, in order to use Swift Testing with SnapshotTesting you must apply the .snapshots trait to your @Suites and/or @Tests:

@Suite(.snapshots)

This is what resets the counter for each test run, and it's what allows you to control the record mode and diff tool used.

Since this isn't an issue with the library I am going to convert it to a discussion. Please feel free to continue the conversation over there!