Split out the preview tests from the unit tests and move them to their own CI tool.

Tools/Sources/Commands/CI/CI.swift

@@ -6,6 +6,7 @@ import Yams
 struct CI: ParsableCommand {
     static let configuration = CommandConfiguration(abstract: "CI workflow commands that can be run both locally and in CI environments.",
                                                     subcommands: [
+                                                        PreviewTests.self,
                                                         AccessibilityTests.self,
                                                         UnitTests.self,
                                                         UITests.self,

Tools/Sources/Commands/CI/PreviewTests.swift

@@ -0,0 +1,42 @@
+import ArgumentParser
+import Foundation
+
+struct PreviewTests: AsyncParsableCommand {
+    static let configuration = CommandConfiguration(commandName: "preview-tests",
+                                                    abstract: "Runs the preview test CI workflow.")
+
+    @Option(help: "iOS version for the simulator.")
+    var osVersion = "26.4"
+
+    private static let scheme = "PreviewTests"
+    private static let device = "iPhone SE (3rd generation)"
+    private static let simulatorType = "com.apple.CoreSimulator.SimDeviceType.iPhone-SE-3rd-generation"
+    private static let testPlanPath = "PreviewTests/SupportingFiles/PreviewTests.xctestplan"
+
+    func run() async throws {
+        var testsFailed = false
+        do {
+            logger.info("\n🧪 Running preview tests…\n")
+            try await RunTests.parse([
+                "--scheme", Self.scheme,
+                "--device", Self.device,
+                "--os-version", osVersion,
+                "--create-simulator-name", Self.device,
+                "--create-simulator-type", Self.simulatorType
+            ]).run()
+        } catch {
+            logger.error("\n❌ Preview tests failed.\n")
+            testsFailed = true
+        }
+
+        // Collect coverage and test results regardless of test outcome (best-effort).
+        await CI.collectCoverage(resultBundle: "\(Self.scheme).xcresult", outputName: "preview-cobertura.xml")
+        await CI.collectTestResults(resultBundle: "\(Self.scheme).xcresult", outputName: "preview-junit.xml")
+
+        if testsFailed {
+            throw ExitCode.failure
+        }
+
+        logger.info("\n✅ Preview tests passed.\n")
+    }
+}

Tools/Sources/Commands/CI/UnitTests.swift

@@ -34,19 +34,10 @@ struct UnitTests: AsyncParsableCommand {
         }
         
         if !skipPreviews {
-            // Run preview tests on a smaller device
             do {
-                logger.info("\n🧪 Running preview tests…\n")
+                try await PreviewTests.parse(["--os-version", osVersion]).run()
-                try await RunTests.parse([
-                    "--scheme", "PreviewTests",
-                    "--device", "iPhone SE (3rd generation)",
-                    "--os-version", osVersion,
-                    "--create-simulator-name", "iPhone SE (3rd generation)",
-                    "--create-simulator-type", "com.apple.CoreSimulator.SimDeviceType.iPhone-SE-3rd-generation"
-                ]).run()
             } catch {
                 failures.append("Preview tests failed: \(error)")
-                logger.error("\n❌ Preview tests failed.\n")
             }
         }
         
@@ -54,13 +45,9 @@ struct UnitTests: AsyncParsableCommand {
         await CI.zipResults(bundles: ["UnitTests.xcresult", "PreviewTests.xcresult"],
                             outputName: "UnitTests.zip")
         
-        // Collect coverage reports
+        // Collect coverage and JUnit results for unit tests
         await CI.collectCoverage(resultBundle: "UnitTests.xcresult", outputName: "unit-cobertura.xml")
-        await CI.collectCoverage(resultBundle: "PreviewTests.xcresult", outputName: "preview-cobertura.xml")
-        
-        // Collect JUnit test results
         await CI.collectTestResults(resultBundle: "UnitTests.xcresult", outputName: "unit-junit.xml")
-        await CI.collectTestResults(resultBundle: "PreviewTests.xcresult", outputName: "preview-junit.xml")
         
         if !failures.isEmpty {
             logger.error("\n❌ \(failures.count) test suite(s) failed.\n")