From 46b5b0c1b9eaf18b7111d703caa6902eb7ae1d26 Mon Sep 17 00:00:00 2001
From: Arthur Liu <arthurliu1994@gmail.com>
Date: Sat, 29 Aug 2026 01:24:33 -0700
Subject: [PATCH] Give HTTPClientError meaningful localized descriptions
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Motivation:

HTTPClientError.localizedDescription currently falls back to Foundation’s generic error 1 message, obscuring the underlying failure.

Modifications:

Conform HTTPClientError to LocalizedError using its existing description and add coverage for errors with and without associated values.

Result:

localizedDescription now preserves the concrete HTTP client error details.
---
 .../AsyncHTTPClient/FoundationExtensions.swift    |  6 ++++++
 .../FoundationExtensionTests.swift                | 15 +++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/Sources/AsyncHTTPClient/FoundationExtensions.swift b/Sources/AsyncHTTPClient/FoundationExtensions.swift
index eeff2ad7e..343470fb1 100644
--- a/Sources/AsyncHTTPClient/FoundationExtensions.swift
+++ b/Sources/AsyncHTTPClient/FoundationExtensions.swift
@@ -21,6 +21,12 @@ import FoundationEssentials
 import Foundation
 #endif
 
+extension HTTPClientError: LocalizedError {
+    public var errorDescription: String? {
+        self.description
+    }
+}
+
 extension HTTPClient.Cookie {
     /// The cookie's expiration date.
     public var expires: Date? {
diff --git a/Tests/AsyncHTTPClientTests/FoundationExtensionTests.swift b/Tests/AsyncHTTPClientTests/FoundationExtensionTests.swift
index 4ff0d6c26..bfc0c8782 100644
--- a/Tests/AsyncHTTPClientTests/FoundationExtensionTests.swift
+++ b/Tests/AsyncHTTPClientTests/FoundationExtensionTests.swift
@@ -19,6 +19,21 @@ import Testing
 
 @Suite
 struct FoundationExtensionTests {
+    @Test
+    func httpClientErrorLocalizedDescriptionUsesDescription() {
+        let error = HTTPClientError.cancelled
+
+        #expect(error.localizedDescription == error.description)
+    }
+
+    @Test
+    func httpClientErrorLocalizedDescriptionPreservesAssociatedValues() {
+        let error = HTTPClientError.unsupportedScheme("custom")
+
+        #expect(error.localizedDescription == error.description)
+        #expect(error.localizedDescription.contains("custom"))
+    }
+
     @Test(arguments: [
         // Format: (input, expected)
         ("localhost", "localhost"),  // Alphanumerics (No encoding needed)