From 82698abf316d261fb4c70a105d96f53254e1718f Mon Sep 17 00:00:00 2001
From: George Barnett <gbarnett@apple.com>
Date: Mon, 28 Apr 2025 10:29:40 +0100
Subject: [PATCH] Add explicit sendability annotations

Motivation:

As part of adopting strict concurrency all public types should be
explicit about whether they are sendable or not.

Modifications:

- Add explicit sendability annotations to a number of types

Result:

Sendability is explicit
---
 Sources/AsyncHTTPClient/AsyncAwait/AnyAsyncSequence.swift   | 3 +++
 Sources/AsyncHTTPClient/AsyncAwait/HTTPClientResponse.swift | 6 ++++++
 .../AsyncAwait/Transaction+StateMachine.swift               | 3 +++
 Sources/AsyncHTTPClient/Base64.swift                        | 2 +-
 Sources/AsyncHTTPClient/Utils.swift                         | 4 ++--
 5 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Sources/AsyncHTTPClient/AsyncAwait/AnyAsyncSequence.swift b/Sources/AsyncHTTPClient/AsyncAwait/AnyAsyncSequence.swift
index 8f6b32bd2..fbcc82ec1 100644
--- a/Sources/AsyncHTTPClient/AsyncAwait/AnyAsyncSequence.swift
+++ b/Sources/AsyncHTTPClient/AsyncAwait/AnyAsyncSequence.swift
@@ -46,3 +46,6 @@ struct AnyAsyncSequence<Element>: Sendable, AsyncSequence {
         .init(nextCallback: self.makeAsyncIteratorCallback())
     }
 }
+
+@available(*, unavailable)
+extension AnyAsyncSequence.AsyncIterator: Sendable {}
diff --git a/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientResponse.swift b/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientResponse.swift
index fa29e6de4..36c1cb36f 100644
--- a/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientResponse.swift
+++ b/Sources/AsyncHTTPClient/AsyncAwait/HTTPClientResponse.swift
@@ -259,3 +259,9 @@ extension HTTPClientResponse.Body {
         .stream(CollectionOfOne(byteBuffer).async)
     }
 }
+
+@available(*, unavailable)
+extension HTTPClientResponse.Body.AsyncIterator: Sendable {}
+
+@available(*, unavailable)
+extension HTTPClientResponse.Body.Storage.AsyncIterator: Sendable {}
diff --git a/Sources/AsyncHTTPClient/AsyncAwait/Transaction+StateMachine.swift b/Sources/AsyncHTTPClient/AsyncAwait/Transaction+StateMachine.swift
index 6cf0dbc07..457627a8a 100644
--- a/Sources/AsyncHTTPClient/AsyncAwait/Transaction+StateMachine.swift
+++ b/Sources/AsyncHTTPClient/AsyncAwait/Transaction+StateMachine.swift
@@ -552,3 +552,6 @@ extension Transaction {
         }
     }
 }
+
+@available(*, unavailable)
+extension Transaction.StateMachine: Sendable {}
diff --git a/Sources/AsyncHTTPClient/Base64.swift b/Sources/AsyncHTTPClient/Base64.swift
index 3162e7251..4d2ddcc49 100644
--- a/Sources/AsyncHTTPClient/Base64.swift
+++ b/Sources/AsyncHTTPClient/Base64.swift
@@ -29,7 +29,7 @@ extension String {
 
 // swift-format-ignore: DontRepeatTypeInStaticProperties
 @usableFromInline
-internal struct Base64 {
+internal struct Base64: Sendable {
 
     @inlinable
     static func encode<Buffer: Collection>(
diff --git a/Sources/AsyncHTTPClient/Utils.swift b/Sources/AsyncHTTPClient/Utils.swift
index abdd5bbc2..985755143 100644
--- a/Sources/AsyncHTTPClient/Utils.swift
+++ b/Sources/AsyncHTTPClient/Utils.swift
@@ -18,10 +18,10 @@ import NIOCore
 ///
 /// ``HTTPClientCopyingDelegate`` discards most parts of a HTTP response, but streams the body
 /// to the `chunkHandler` provided on ``init(chunkHandler:)``. This is mostly useful for testing.
-public final class HTTPClientCopyingDelegate: HTTPClientResponseDelegate {
+public final class HTTPClientCopyingDelegate: HTTPClientResponseDelegate, Sendable {
     public typealias Response = Void
 
-    let chunkHandler: (ByteBuffer) -> EventLoopFuture<Void>
+    let chunkHandler: @Sendable (ByteBuffer) -> EventLoopFuture<Void>
 
     @preconcurrency
     public init(chunkHandler: @Sendable @escaping (ByteBuffer) -> EventLoopFuture<Void>) {