Drop support for Swift 5.7 (#485)

Author: fabianfett

.github/workflows/test.yml

@@ -18,7 +18,6 @@ jobs:
       fail-fast: false
       matrix:
         swift-image:
-          - swift:5.7-jammy
           - swift:5.8-jammy
           - swift:5.9-jammy
           - swift:5.10-noble

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version:5.7
+// swift-tools-version:5.8
 import PackageDescription
 
 let package = Package(

README.md

@@ -16,7 +16,7 @@
     <img src="https://img.shields.io/github/actions/workflow/status/vapor/postgres-nio/test.yml?event=push&style=plastic&logo=github&label=tests&logoColor=%23ccc" alt="Continuous Integration">
 </a>
 <a href="https://swift.org">
-    <img src="https://design.vapor.codes/images/swift57up.svg" alt="Swift 5.7+">
+    <img src="https://design.vapor.codes/images/swift58up.svg" alt="Swift 5.8+">
 </a>
 <a href="https://www.swift.org/sswg/incubation-process.html">
     <img src="https://design.vapor.codes/images/sswg-graduated.svg" alt="SSWG Incubation Level: Graduated">
@@ -167,7 +167,7 @@ Please see [SECURITY.md] for details on the security process.
 [Team Chat]: https://discord.gg/vapor
 [MIT License]: LICENSE
 [Continuous Integration]: https://github.com/vapor/postgres-nio/actions
-[Swift 5.7]: https://swift.org
+[Swift 5.8]: https://swift.org
 [Security.md]: https://github.com/vapor/.github/blob/main/SECURITY.md
 
 [`PostgresConnection`]: https://api.vapor.codes/postgresnio/documentation/postgresnio/postgresconnection

Sources/ConnectionPoolModule/ConnectionPool.swift

@@ -273,7 +273,7 @@ public final class ConnectionPool<
 
     public func run() async {
         await withTaskCancellationHandler {
-            #if swift(>=5.8) && os(Linux) || swift(>=5.9)
+            #if os(Linux) || compiler(>=5.9)
             if #available(macOS 14.0, iOS 17.0, tvOS 17.0, watchOS 10.0, *) {
                 return await withDiscardingTaskGroup() { taskGroup in
                     await self.run(in: &taskGroup)
@@ -313,7 +313,7 @@ public final class ConnectionPool<
         case scheduleTimer(StateMachine.Timer)
     }
 
-    #if swift(>=5.8) && os(Linux) || swift(>=5.9)
+    #if os(Linux) || compiler(>=5.9)
     @available(macOS 14.0, iOS 17.0, tvOS 17.0, watchOS 10.0, *)
     private func run(in taskGroup: inout DiscardingTaskGroup) async {
         for await event in self.eventStream {
@@ -507,7 +507,7 @@ public final class ConnectionPool<
             await withTaskGroup(of: TimerRunResult.self, returning: Void.self) { taskGroup in
                 taskGroup.addTask {
                     do {
-                        #if swift(>=5.8) && os(Linux) || swift(>=5.9)
+                        #if os(Linux) || compiler(>=5.9)
                         try await self.clock.sleep(for: timer.duration)
                         #else
                         try await self.clock.sleep(until: self.clock.now.advanced(by: timer.duration), tolerance: nil)
@@ -593,7 +593,7 @@ protocol TaskGroupProtocol {
     mutating func addTask_(operation: @escaping @Sendable () async -> Void)
 }
 
-#if swift(>=5.8) && os(Linux) || swift(>=5.9)
+#if os(Linux) || swift(>=5.9)
 @available(macOS 14.0, iOS 17.0, tvOS 17.0, watchOS 10.0, *)
 extension DiscardingTaskGroup: TaskGroupProtocol {
     @inlinable

Sources/PostgresNIO/New/NotificationListener.swift

@@ -142,7 +142,7 @@ final class NotificationListener: @unchecked Sendable {
 }
 
 
-#if swift(<5.9)
+#if compiler(<5.9)
 // Async stream API backfill
 extension AsyncThrowingStream {
     static func makeStream(

Sources/PostgresNIO/New/PostgresNotificationSequence.swift

@@ -3,7 +3,7 @@ public struct PostgresNotification: Sendable {
     public let payload: String
 }
 
-public struct PostgresNotificationSequence: AsyncSequence {
+public struct PostgresNotificationSequence: AsyncSequence, Sendable {
     public typealias Element = PostgresNotification
 
     let base: AsyncThrowingStream<PostgresNotification, Error>
@@ -20,8 +20,3 @@ public struct PostgresNotificationSequence: AsyncSequence {
         }
     }
 }
-
-#if swift(>=5.7)
-// AsyncThrowingStream is marked as Sendable in Swift 5.6
-extension PostgresNotificationSequence: Sendable {}
-#endif

Sources/PostgresNIO/Utilities/Exports.swift

@@ -1,14 +1,3 @@
-#if swift(>=5.8)
-
 @_documentation(visibility: internal) @_exported import NIO
 @_documentation(visibility: internal) @_exported import NIOSSL
 @_documentation(visibility: internal) @_exported import struct Logging.Logger
-
-#else
-
-// TODO: Remove this with the next major release!
-@_exported import NIO
-@_exported import NIOSSL
-@_exported import struct Logging.Logger
-
-#endif