From e9208d7db14f5d0876bfa4d5f4b430efed4724bc Mon Sep 17 00:00:00 2001
From: Declan McCue <d_mccue@apple.com>
Date: Fri, 2 Oct 2026 09:26:49 -0400
Subject: [PATCH] Skip tests instead of failing when in debug configurations,
 or when 'XC_PROJECT_FORMAT_TEST_PROJECT_SOURCE_DIR' is unavailable.

---
 Package.swift                       |  2 +-
 Sources/Tests/SampleData.swift      | 11 ++++++++++-
 Sources/Tests/TestPerformance.swift | 16 ++++++++++------
 3 files changed, 21 insertions(+), 8 deletions(-)

diff --git a/Package.swift b/Package.swift
index b6c141e..2b0635f 100644
--- a/Package.swift
+++ b/Package.swift
@@ -48,7 +48,7 @@ let package = Package(
 )
 
 for target in package.targets {
-    target.swiftSettings = [
+    target.swiftSettings = (target.swiftSettings ?? []) + [
         .enableUpcomingFeature("ExistentialAny"),
         .enableUpcomingFeature("ImmutableWeakCaptures"),
         .enableUpcomingFeature("InferIsolatedConformances"),
diff --git a/Sources/Tests/SampleData.swift b/Sources/Tests/SampleData.swift
index 79d0320..676ea84 100644
--- a/Sources/Tests/SampleData.swift
+++ b/Sources/Tests/SampleData.swift
@@ -11,6 +11,12 @@ import Foundation
 
 
 struct SampleData : Sendable {
+    static let sourceDirectoryEnvironmentVariable = "XC_PROJECT_FORMAT_TEST_PROJECT_SOURCE_DIR"
+
+    static var sourceDirectory: String? {
+        ProcessInfo.processInfo.environment[sourceDirectoryEnvironmentVariable]
+    }
+
     static let sharedInstance = Result {
         try SampleData()
     }
@@ -32,11 +38,14 @@ struct SampleData : Sendable {
     let records: [Record]
     init(sourceDirectory: String) throws {
         let paths = try FileManager.default.recursivelyFindFiles(matchingExtension: "xcproj", in: sourceDirectory)
+        guard !paths.isEmpty else {
+            throw NSError("No .xcproj files found in \(sourceDirectory.quoted)")
+        }
         self.records = try paths.map(Record.init(path:))
     }
 
     init() throws {
-        try self.init(sourceDirectory: ProcessInfo.processInfo.environment["XC_PROJECT_FORMAT_TEST_PROJECT_SOURCE_DIR"].unwrap(orThrow: "Missing environment variable for \("XC_PROJECT_FORMAT_TEST_PROJECT_SOURCE_DIR".quoted)"))
+        try self.init(sourceDirectory: Self.sourceDirectory.unwrap(orThrow: "Missing environment variable for \(Self.sourceDirectoryEnvironmentVariable.quoted)"))
     }
 }
 
diff --git a/Sources/Tests/TestPerformance.swift b/Sources/Tests/TestPerformance.swift
index 20d939e..5670649 100644
--- a/Sources/Tests/TestPerformance.swift
+++ b/Sources/Tests/TestPerformance.swift
@@ -16,9 +16,18 @@ extension TimeInterval {
     }
 }
 
+#if ENABLE_PERFORMANCE_TESTS
+private let arePerformanceTestsEnabled = true
+#else
+private let arePerformanceTestsEnabled = false
+#endif
+
+@Suite(
+    .enabled(if: arePerformanceTestsEnabled, "Performance tests are only enabled in release builds."),
+    .enabled(if: SampleData.sourceDirectory != nil, "Set \(SampleData.sourceDirectoryEnvironmentVariable) to a directory of sample projects to run performance tests.")
+)
 struct TestPerformance {
     func measureTransformingSampleProjectData<Result>(testName: String = #function, body: (SampleData.Record) throws -> Result) throws {
-        #if ENABLE_PERFORMANCE_TESTS
         let sampleData = try SampleData.sharedInstance.get()
         let testDurations = try Array(repetitions: 100) {
             try measureDuration {
@@ -38,11 +47,6 @@ struct TestPerformance {
         print("    mean: \(mean?.formattedSeconds() ?? "N/A")")
         print("  median: \(median?.formattedSeconds() ?? "N/A")")
         print("   total: \(total.formattedSeconds())")
-        #else
-        #if compiler(>=6.3)
-        try Test.cancel("Performance tests are only enabled in release builds.")
-        #endif
-        #endif
     }
 
     @Test func testAnyJSONSerializationInstantiationPerformance() throws {