Bump minimum Swift version to 5.7 (#712)

Motivation:

Now that Swift 5.9 is GM we should update the supported versions and
remove 5.6

Modifications:

* Update `Package.swift`
* Remove `#if swift(>=5.7)` guards
* Delete the 5.6 docker compose file and make a 5.10 one
* Update docs

Result:

Remove support for Swift 5.6, add 5.10

Author: rnro

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.6
+// swift-tools-version:5.7
 //===----------------------------------------------------------------------===//
 //
 // This source file is part of the AsyncHTTPClient open source project

README.md

@@ -328,4 +328,5 @@ AsyncHTTPClient     | Minimum Swift Version
 `1.5.0 ..< 1.10.0`  | 5.2
 `1.10.0 ..< 1.13.0` | 5.4
 `1.13.0 ..< 1.18.0` | 5.5.2
-`1.18.0 ...`        | 5.6
+`1.18.0 ..< 1.20.0` | 5.6
+`1.20.0 ...`        | 5.7

Sources/AsyncHTTPClient/HTTPClient.swift

@@ -166,22 +166,13 @@ public class HTTPClient {
         }
     }
 
-    #if swift(>=5.7)
     /// Shuts down the client and `EventLoopGroup` if it was created by the client.
     ///
     /// This method blocks the thread indefinitely, prefer using ``shutdown()-96ayw``.
     @available(*, noasync, message: "syncShutdown() can block indefinitely, prefer shutdown()", renamed: "shutdown()")
     public func syncShutdown() throws {
         try self.syncShutdown(requiresCleanClose: false)
     }
-    #else
-    /// Shuts down the client and `EventLoopGroup` if it was created by the client.
-    ///
-    /// This method blocks the thread indefinitely, prefer using ``shutdown()-96ayw``.
-    public func syncShutdown() throws {
-        try self.syncShutdown(requiresCleanClose: false)
-    }
-    #endif
 
     /// Shuts down the client and `EventLoopGroup` if it was created by the client.
     ///
@@ -921,9 +912,7 @@ extension HTTPClient {
     }
 }
 
-#if swift(>=5.7)
 extension HTTPClient.Configuration: Sendable {}
-#endif
 
 extension HTTPClient.EventLoopGroupProvider: Sendable {}
 extension HTTPClient.EventLoopPreference: Sendable {}

Sources/AsyncHTTPClient/HTTPHandler.swift

@@ -750,7 +750,6 @@ extension HTTPClient {
             return self.promise.futureResult
         }
 
-        #if swift(>=5.7)
         /// Waits for execution of this request to complete.
         ///
         /// - returns: The value of  ``futureResult`` when it completes.
@@ -759,15 +758,6 @@ extension HTTPClient {
         public func wait() throws -> Response {
             return try self.promise.futureResult.wait()
         }
-        #else
-        /// Waits for execution of this request to complete.
-        ///
-        /// - returns: The value of ``futureResult`` when it completes.
-        /// - throws: The error value of ``futureResult`` if it errors.
-        public func wait() throws -> Response {
-            return try self.promise.futureResult.wait()
-        }
-        #endif
 
         /// Provides the result of this request.
         ///

Tests/AsyncHTTPClientTests/HTTPClientRequestTests.swift

@@ -522,7 +522,6 @@ class HTTPClientRequestTests: XCTestCase {
         XCTAssertEqual(body, expectedChunks)
     }
 
-    #if swift(>=5.7)
     func testChunkingSequenceFastPath() async throws {
         func makeBytes() -> some Sequence<UInt8> & Sendable {
             Array(repeating: 0, count: bagOfBytesToByteBufferConversionChunkSize) +
@@ -569,7 +568,6 @@ class HTTPClientRequestTests: XCTestCase {
 
         XCTAssertEqual(body, expectedChunks)
     }
-    #endif
 
     func testBodyStringChunking() throws {
         let body = try HTTPClient.Body.string(

docker/docker-compose.2004.56.yaml

@@ -0,0 +1,21 @@
+version: "3"
+
+services:
+
+  runtime-setup:
+    image: async-http-client:22.04-5.10
+    build:
+      args:
+        base_image: "swiftlang/swift:nightly-5.10-jammy"
+
+  documentation-check:
+    image: async-http-client:22.04-5.10
+
+  test:
+    image: async-http-client:22.04-5.10
+    environment:
+      - IMPORT_CHECK_ARG=--explicit-target-dependency-import-check error
+      #- SANITIZER_ARG=--sanitize=thread
+
+  shell:
+    image: async-http-client:22.04-5.10

docker/docker-compose.2204.510.yaml

@@ -6,7 +6,8 @@ services:
     image: async-http-client:22.04-5.9
     build:
       args:
-        base_image: "swiftlang/swift:nightly-5.9-jammy"
+        ubuntu_version: "jammy"
+        swift_version: "5.9"
 
   documentation-check:
     image: async-http-client:22.04-5.9