Remove Snapshot types from non-Darwin builds.

Package.swift

@@ -132,6 +132,7 @@ extension Array where Element == PackageDescription.SwiftSetting {
 
       .define("SWT_NO_FILE_IO", .when(platforms: [.wasi])),
       .define("SWT_NO_EXIT_TESTS", .when(platforms: [.iOS, .watchOS, .tvOS, .visionOS, .wasi])),
+      .define("SWT_NO_SNAPSHOT_TYPES", .when(platforms: [.linux, .windows, .wasi])),
     ]
   }
 

Sources/Testing/ABI/EntryPoints/EntryPoint.swift

@@ -512,10 +512,12 @@ public func configurationForEntryPoint(from args: __CommandLineArguments_v0) thr
 /// - Throws: If `version` is not a supported ABI version.
 func eventHandlerForStreamingEvents(version: Int?, forwardingTo eventHandler: @escaping @Sendable (UnsafeRawBufferPointer) -> Void) throws -> Event.Handler {
   switch version {
+#if !SWT_NO_SNAPSHOT_TYPES
   case -1:
     // Legacy support for Xcode 16 betas. Support for this undocumented version
     // will be removed in a future update. Do not use it.
     eventHandlerForStreamingEventSnapshots(to: eventHandler)
+#endif
   case nil, 0:
     ABIv0.Record.eventHandler(forwardingTo: eventHandler)
   case let .some(unsupportedVersion):
@@ -547,7 +549,7 @@ private func _writeJSONLine(_ json: UnsafeRawBufferPointer, to file: borrowing F
   if _slowPath(json.contains(where: isASCIINewline)) {
 #if DEBUG
     let message = Event.ConsoleOutputRecorder.warning(
-      "JSON encoder produced one or more newline characters while encoding an event snapshot. Please file a bug report at https://github.com/apple/swift-testing/issues/new",
+      "JSON encoder produced one or more newline characters while encoding an event to JSON. Please file a bug report at https://github.com/apple/swift-testing/issues/new",
       options: .for(.stderr)
     )
 #if SWT_TARGET_OS_APPLE

Sources/Testing/ABI/v0/ABIv0.Record+Streaming.swift

@@ -45,6 +45,7 @@ extension ABIv0.Record {
   }
 }
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Experimental event streaming
 
 /// A type containing an event snapshot and snapshots of the contents of an
@@ -107,3 +108,4 @@ func eventHandlerForStreamingEventSnapshots(
   }
 }
 #endif
+#endif

Sources/Testing/Events/Event.swift

@@ -287,6 +287,7 @@ extension Event {
   }
 }
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Snapshotting
 
 extension Event {
@@ -509,3 +510,4 @@ extension Event.Context {
     }
   }
 }
+#endif

Sources/Testing/Expectations/Expectation.swift

@@ -53,6 +53,7 @@ public struct ExpectationFailedError: Error {
   public var expectation: Expectation
 }
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Snapshotting
 
 extension Expectation {
@@ -100,3 +101,4 @@ extension Expectation {
     }
   }
 }
+#endif

Sources/Testing/Issues/ErrorSnapshot.swift

@@ -8,6 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
+#if !SWT_NO_SNAPSHOT_TYPES
 /// A serializable snapshot of an `Error` value.
 ///
 /// This type conforms to `Error` as well, meaning it can be thrown and treated
@@ -40,3 +41,4 @@ extension ErrorSnapshot: CustomStringConvertible {}
 // MARK: - Codable
 
 extension ErrorSnapshot: Codable {}
+#endif

Sources/Testing/Issues/Issue.swift

@@ -194,6 +194,7 @@ extension Issue.Kind: CustomStringConvertible {
   }
 }
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Snapshotting
 
 extension Issue {
@@ -476,3 +477,4 @@ extension Issue.Kind.Snapshot: CustomStringConvertible {
     }
   }
 }
+#endif

Sources/Testing/Parameterization/Test.Case.swift

@@ -160,6 +160,7 @@ extension Test.Case.Argument.ID: Codable {}
 extension Test.Parameter: Hashable {}
 extension Test.Case.Argument.ID: Hashable {}
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Snapshotting
 
 extension Test.Case {
@@ -215,3 +216,4 @@ extension Test.Case.Argument {
     }
   }
 }
+#endif

Sources/Testing/Running/Runner.Plan.swift

@@ -303,6 +303,7 @@ extension Runner.Plan {
   }
 }
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Snapshotting
 
 extension Runner.Plan {
@@ -430,3 +431,4 @@ extension Runner.Plan.Action {
     }
   }
 }
+#endif

Sources/Testing/Test.swift

@@ -271,6 +271,7 @@ extension Test: Equatable, Hashable {
   }
 }
 
+#if !SWT_NO_SNAPSHOT_TYPES
 // MARK: - Snapshotting
 
 extension Test {
@@ -388,3 +389,4 @@ extension Test {
     }
   }
 }
+#endif

Tests/TestingTests/EventTests.swift

@@ -8,6 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
+#if !SWT_NO_SNAPSHOT_TYPES
 @testable @_spi(Experimental) @_spi(ForToolsIntegrationOnly) import Testing
 #if SWT_BUILDING_WITH_CMAKE
 @_implementationOnly import _TestingInternals
@@ -80,3 +81,4 @@ struct EventTests {
   }
 #endif
 }
+#endif

Tests/TestingTests/IssueTests.swift

@@ -1419,6 +1419,7 @@ final class IssueTests: XCTestCase {
 }
 #endif
 
+#if !SWT_NO_SNAPSHOT_TYPES
 @Suite("Issue Codable Conformance Tests")
 struct IssueCodingTests {
 
@@ -1531,6 +1532,7 @@ struct IssueCodingTests {
     #expect(String(reflecting: issueSnapshot) == String(reflecting: issue))
   }
 }
+#endif
 
 // MARK: - Fixtures
 

Tests/TestingTests/PlanTests.swift

@@ -421,19 +421,21 @@ struct PlanTests {
     #expect(plan.stepGraph.subgraph(at: typeInfo.fullyQualifiedNameComponents + CollectionOfOne("reserved1(reserved2:)")) != nil)
   }
 
+#if !SWT_NO_SNAPSHOT_TYPES
   @Test("Test cases of a disabled test are not evaluated")
   func disabledTestCases() async throws {
     var configuration = Configuration()
     configuration.setEventHandler { event, context in
       guard case .testSkipped = event.kind else {
         return
       }
-      let testSnapshot = try #require(context.test.map({ Test.Snapshot(snapshotting: $0 )}))
+      let testSnapshot = try #require(context.test.map { Test.Snapshot(snapshotting: $0) })
       #expect(testSnapshot.testCases?.isEmpty ?? false)
     }
 
     await runTestFunction(named: "disabled(x:)", in: ParameterizedTests.self, configuration: configuration)
   }
+#endif
 }
 
 // MARK: - Fixtures

Tests/TestingTests/Runner.Plan.SnapshotTests.swift

@@ -8,6 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
+#if !SWT_NO_SNAPSHOT_TYPES
 @testable @_spi(ForToolsIntegrationOnly) import Testing
 
 @Suite("Runner.Plan.Snapshot tests")
@@ -66,3 +67,4 @@ private struct Runner_Plan_SnapshotFixtures {
   @Test(.hidden, .enabled(if: try _erroneousCondition(), "To demonstrate recordIssue action"))
   func erroneousTest() {}
 }
+#endif

Tests/TestingTests/SwiftPMTests.swift

@@ -229,7 +229,7 @@ struct SwiftPMTests {
         ])
   func eventStreamOutput(outputArgumentName: String, versionArgumentName: String, version: String) async throws {
     // Test that JSON records are successfully streamed to a file and can be
-    // read back as snapshots.
+    // read back into memory and decoded.
     let tempDirPath = try temporaryDirectory()
     let temporaryFilePath = appendPathComponent("\(UInt64.random(in: 0 ..< .max))", to: tempDirPath)
     defer {

Tests/TestingTests/Test.SnapshotTests.swift

@@ -8,6 +8,7 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
+#if !SWT_NO_SNAPSHOT_TYPES
 @_spi(Experimental) @_spi(ForToolsIntegrationOnly) @testable import Testing
 
 @Suite("Test.Snapshot tests")
@@ -129,3 +130,4 @@ struct Test_SnapshotTests {
 extension Tag {
   @Tag fileprivate static var testTag: Self
 }
+#endif

cmake/modules/shared/CompilerSettings.cmake

@@ -29,3 +29,6 @@ endif()
 if(CMAKE_SYSTEM_NAME IN_LIST "iOS;watchOS;tvOS;visionOS;WASI")
   add_compile_definitions("SWT_NO_EXIT_TESTS")
 endif()
+if(NOT APPLE)
+  add_compile_definitions("SWT_NO_SNAPSHOT_TYPES")
+endif()