Swift Testing doesn't have 'Attached Recorded Snapshot' in Xcode report navigator

[adammcarter]

Describe the bug
When writing snapshot tests in XCTest a failed test produces some output in the Xcode report navigator which has attachments for the failed images, including a diff image when the test fails due to mismatching images.

When writing these in Swift Testing, no output images are available in the Xcode report navigator to quickly preview.

To Reproduce
snapshotsdemo.zip

import SnapshotTesting
import Testing
import XCTest


@MainActor
@Suite
struct LegacySnapshots {
  @Test
  func example() {
    let view = makeLabel("Some label")

    assertSnapshot(of: view, as: .image)
  }
}


@MainActor
final class LegacySnapshotsTests: XCTestCase {
  func testExample() {
    let view = makeLabel("Some label")

    assertSnapshot(of: view, as: .image)
  }
}


@MainActor
private func makeLabel(_ text: String) -> UIView {
  let label = UILabel()
  label.font = .systemFont(ofSize: UIFont.systemFontSize)
  label.text = text
  label.sizeToFit()

  return label
}

Expected behavior
Expected the 'Attached Recorded Snapshot' in Xcode report navigator

Screenshots

XCTest:

Swift Testing test:

Environment

• swift-snapshot-testing version: 1.18.3
• Xcode 16.3
• Swift version: swift-driver version: 1.120.5 Apple Swift version 6.1 (swiftlang-6.1.0.110.21 clang-1700.0.13.3) Target: arm64-apple-macosx15.0
• OS: iOS 18.4

Additional context
n/a

[mbrandonw]

Hi @adammcarter, Swift Testing does currently support attachments, but may soon. Until then there isn’t much we can do.

Converting this to a discussion for now, and feel free to keep the conversation going there.

[adammcarter]

Thanks @mbrandonw for the quick reply, thought this might be the case.

Is there any discussion somewhere on it 'soon' supporting attachments?

[mbrandonw]

The proposal was recently accepted here.

[Jon889]

Is there somewhere known/accessible on disk the failure and diffs are saved to disk instead of being attached?

[adammcarter]

You should be able to see the locations on the test failure within the test report.

There should be two paths,

The top one is the reference image and the bottom one (in a temp folder IIRC) is the failure image.

[Jon889]

That doesn’t really help with CI. I found there’s a SNAPSHOTS_ARTIFACT environment variable that can be set to store the failed images in, but no ability to save the diffs