From 90dc6875693bec43ed042dc96cf08bc2ff4ef5b3 Mon Sep 17 00:00:00 2001
From: Julian <julian@bitrig.com>
Date: Thu, 12 Mar 2026 22:55:50 -0700
Subject: [PATCH] fix: propagate errors from asset modification date lookup

---
 Sources/XCDocsBridge/DocumentationAssetLocator.swift   | 8 ++++----
 Tests/XCDocsTests/DocumentationAssetLocatorTests.swift | 8 ++++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/Sources/XCDocsBridge/DocumentationAssetLocator.swift b/Sources/XCDocsBridge/DocumentationAssetLocator.swift
index 1142018..4585820 100644
--- a/Sources/XCDocsBridge/DocumentationAssetLocator.swift
+++ b/Sources/XCDocsBridge/DocumentationAssetLocator.swift
@@ -18,7 +18,7 @@ package struct DocumentationAssetLocator {
         let contents = try assetRootContents()
 
         let candidates = try contents.filter { $0.pathExtension == "asset" }.filter { try hasReadableIndex(at: $0) }
-            .sorted { lhs, rhs in modificationDate(for: lhs) > modificationDate(for: rhs) }
+            .sorted { lhs, rhs in try modificationDate(for: lhs) > modificationDate(for: rhs) }
 
         guard let assetURL = candidates.first else {
             throw BridgeError(
@@ -98,8 +98,8 @@ package struct DocumentationAssetLocator {
         return nsError.code == NSFileNoSuchFileError || nsError.code == NSFileReadNoSuchFileError
     }
 
-    private func modificationDate(for url: URL) -> Date {
-        let resourceValues = try? url.resourceValues(forKeys: [.contentModificationDateKey])
-        return resourceValues?.contentModificationDate ?? .distantPast
+    package func modificationDate(for url: URL) throws -> Date {
+        let resourceValues = try url.resourceValues(forKeys: [.contentModificationDateKey])
+        return resourceValues.contentModificationDate ?? .distantPast
     }
 }
diff --git a/Tests/XCDocsTests/DocumentationAssetLocatorTests.swift b/Tests/XCDocsTests/DocumentationAssetLocatorTests.swift
index 0d805fb..4798a79 100644
--- a/Tests/XCDocsTests/DocumentationAssetLocatorTests.swift
+++ b/Tests/XCDocsTests/DocumentationAssetLocatorTests.swift
@@ -163,6 +163,14 @@ struct DocumentationAssetLocatorTests {
         #expect(error.code == .assetNotFound)
     }
 
+    @Test
+    func propagatesErrorWhenModificationDateLookupFails() throws {
+        let nonexistentURL = URL(fileURLWithPath: "/tmp/nonexistent-\(UUID().uuidString).asset")
+        let locator = DocumentationAssetLocator()
+
+        #expect(throws: (any Error).self) { try locator.modificationDate(for: nonexistentURL) }
+    }
+
     @Test
     func selectsTheNewestValidAsset() throws {
         let rootURL = try makeTemporaryDirectory()