From d465f500e3b452d9d3d01c03063af71ee7bff8cf Mon Sep 17 00:00:00 2001
From: Mihaela Mihaljevic <mihaelamj@me.com>
Date: Sat, 18 Jul 2026 23:43:59 +0200
Subject: [PATCH] fix(tests): normalize lastPathComponent for Linux Foundation

Darwin's Foundation returns String from URL.lastPathComponent;
swift-corelibs-foundation on this toolchain returns String?. The three
uses in TaggedNodeCorpusRoundTripTests (a sort comparator and two
Testing.Comment interpolations) compiled on Darwin but failed the
Linux build outright, an unrelated pre-existing gap surfaced while
verifying the anchor-expansion-bomb fix on the Linux CI relay.

An explicit `(url.lastPathComponent as String?) ?? ""` coercion makes
both platforms produce a uniform String? before the `??`, rather than
picking one platform's non-optional type and breaking the other.

Verified via a full clean macOS build and test run (674 tests, all
passing) and swiftformat/swiftlint --strict clean.
---
 CHANGELOG.md                               |  6 ++++++
 Tests/TaggedNodeCorpusRoundTripTests.swift | 13 ++++++++++---
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1e721e0..061ef8c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -446,6 +446,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   produce. A document with genuinely wide but non-exponential alias
   reuse (the same anchor referenced thousands of times at one level, no
   nesting) still parses normally.
+- `TaggedNodeCorpusRoundTripTests` now normalizes `URL.lastPathComponent`
+  through an explicit `as String?` coercion before use: this toolchain's
+  swift-corelibs-foundation returns `String?` where Darwin's Foundation
+  returns `String`, and the mismatch failed the Linux build outright
+  (an unrelated pre-existing gap surfaced while verifying the
+  anchor-expansion fix above on the Linux CI relay).
 
 ## [0.2.0] - 2026-07-05
 
diff --git a/Tests/TaggedNodeCorpusRoundTripTests.swift b/Tests/TaggedNodeCorpusRoundTripTests.swift
index 9f94e8e..3fdcef5 100644
--- a/Tests/TaggedNodeCorpusRoundTripTests.swift
+++ b/Tests/TaggedNodeCorpusRoundTripTests.swift
@@ -19,7 +19,14 @@ struct TaggedNodeCorpusRoundTripTests {
         ))
         var accepted = 0
         var rejected = 0
-        for url in urls.sorted(by: { $0.lastPathComponent < $1.lastPathComponent }) {
+        /// `URL.lastPathComponent` is `String` on Darwin's Foundation but `String?` on this
+        /// toolchain's swift-corelibs-foundation; the explicit `as String?` upcast/coercion makes
+        /// both platforms produce a uniform `String?` here so `?? ""` compiles identically either
+        /// way, rather than picking one platform's non-optional type and breaking the other.
+        func name(_ url: URL) -> String {
+            (url.lastPathComponent as String?) ?? ""
+        }
+        for url in urls.sorted(by: { name($0) < name($1) }) {
             let source = try String(contentsOf: url, encoding: .utf8)
             let parsed: PureYAML.Tagged.Node
             do {
@@ -34,11 +41,11 @@ struct TaggedNodeCorpusRoundTripTests {
             do {
                 reparsed = try PureYAML.parseTagged(dumped)
             } catch {
-                Issue.record("\(url.lastPathComponent): dump produced unparseable YAML: \(error)")
+                Issue.record("\(name(url)): dump produced unparseable YAML: \(error)")
                 continue
             }
             if let detail = firstDivergence(parsed, reparsed, path: "$") {
-                Issue.record("\(url.lastPathComponent): \(detail)")
+                Issue.record("\(name(url)): \(detail)")
             }
         }
         #expect(accepted > 0)