From 859fadd897ed7335c65edc008a91d27887b147c4 Mon Sep 17 00:00:00 2001
From: Jonathan Grynspan <jgrynspan@apple.com>
Date: Thu, 6 Nov 2025 16:02:13 -0500
Subject: [PATCH] Fix a regression that prevents saving attachments.

This PR ensures that the attachment-saving logic in `Runner` is applied
consistently. I made the mistake of moving that logic to
`configureEventHandlerRuntimeState()` because I'd forgotten that that
function only has an effect when we're running our own tests. And, as a
result, all our tests continued to pass because the code was in place
for our tests (and for nobody else.)

I've moved the code to a different location that we will always call
when running a `Runner` instance, so the issue is resolved now. I don't
have a great way to set up a unit test for this; tested manually at
desk.
---
 Sources/Testing/Attachments/Attachment.swift  | 22 ++++++++++++++++++-
 .../Testing/Running/Runner.RuntimeState.swift | 10 ---------
 Sources/Testing/Running/Runner.swift          |  1 +
 3 files changed, 22 insertions(+), 11 deletions(-)

diff --git a/Sources/Testing/Attachments/Attachment.swift b/Sources/Testing/Attachments/Attachment.swift
index b22911919..40d498433 100644
--- a/Sources/Testing/Attachments/Attachment.swift
+++ b/Sources/Testing/Attachments/Attachment.swift
@@ -501,6 +501,26 @@ extension Attachment where AttachableValue: ~Copyable {
   }
 }
 
+extension Runner {
+  /// Modify this runner's configured event handler so that it handles "value
+  /// attached" events and saves attachments where necessary.
+  mutating func configureAttachmentHandling() {
+    configuration.eventHandler = { [oldEventHandler = configuration.eventHandler] event, context in
+#if !SWT_NO_FILE_IO
+      var event = copy event
+      if case .valueAttached = event.kind {
+        guard let configuration = context.configuration,
+              configuration.handleValueAttachedEvent(&event, in: context) else {
+          // The attachment could not be handled, so suppress this event.
+          return
+        }
+      }
+      oldEventHandler(event, context)
+#endif
+    }
+  }
+}
+
 extension Configuration {
   /// Handle the given "value attached" event.
   ///
@@ -517,7 +537,7 @@ extension Configuration {
   /// not need to call it elsewhere. It automatically saves the attachment
   /// associated with `event` and modifies `event` to include the path where the
   /// attachment was saved.
-  func handleValueAttachedEvent(_ event: inout Event, in eventContext: borrowing Event.Context) -> Bool {
+  fileprivate func handleValueAttachedEvent(_ event: inout Event, in eventContext: borrowing Event.Context) -> Bool {
     guard let attachmentsPath else {
       // If there is no path to which attachments should be written, there's
       // nothing to do here. The event handler may still want to handle it.
diff --git a/Sources/Testing/Running/Runner.RuntimeState.swift b/Sources/Testing/Running/Runner.RuntimeState.swift
index 2d22002c5..eb892da62 100644
--- a/Sources/Testing/Running/Runner.RuntimeState.swift
+++ b/Sources/Testing/Running/Runner.RuntimeState.swift
@@ -48,16 +48,6 @@ extension Runner {
     }
 
     configuration.eventHandler = { [oldEventHandler = configuration.eventHandler] event, context in
-#if !SWT_NO_FILE_IO
-      var event = copy event
-      if case .valueAttached = event.kind {
-        guard let configuration = context.configuration,
-              configuration.handleValueAttachedEvent(&event, in: context) else {
-          // The attachment could not be handled, so suppress this event.
-          return
-        }
-      }
-#endif
       RuntimeState.$current.withValue(existingRuntimeState) {
         oldEventHandler(event, context)
       }
diff --git a/Sources/Testing/Running/Runner.swift b/Sources/Testing/Running/Runner.swift
index 1cedf6182..e67b7cd8b 100644
--- a/Sources/Testing/Running/Runner.swift
+++ b/Sources/Testing/Running/Runner.swift
@@ -416,6 +416,7 @@ extension Runner {
   private static func _run(_ runner: Self) async {
     var runner = runner
     runner.configureEventHandlerRuntimeState()
+    runner.configureAttachmentHandling()
 
     // Track whether or not any issues were recorded across the entire run.
     let issueRecorded = Locked(rawValue: false)