Workaround DiscardingTaskGroup non-conformance with nightly compilers (#478)

Author: weissi

Sources/ConnectionPoolModule/ConnectionPool.swift

@@ -419,7 +419,7 @@ public final class ConnectionPool<
 
     @inlinable
     /*private*/ func makeConnection(for request: StateMachine.ConnectionRequest, in taskGroup: inout some TaskGroupProtocol) {
-        taskGroup.addTask {
+        taskGroup.addTask_ {
             self.observabilityDelegate.startedConnecting(id: request.connectionID)
 
             do {
@@ -468,7 +468,7 @@ public final class ConnectionPool<
     /*private*/ func runKeepAlive(_ connection: Connection, in taskGroup: inout some TaskGroupProtocol) {
         self.observabilityDelegate.keepAliveTriggered(id: connection.id)
 
-        taskGroup.addTask {
+        taskGroup.addTask_ {
             do {
                 try await self.keepAliveBehavior.runKeepAlive(for: connection)
 
@@ -503,7 +503,7 @@ public final class ConnectionPool<
 
     @inlinable
     /*private*/ func runTimer(_ timer: StateMachine.Timer, in poolGroup: inout some TaskGroupProtocol) {
-        poolGroup.addTask { () async -> () in
+        poolGroup.addTask_ { () async -> () in
             await withTaskGroup(of: TimerRunResult.self, returning: Void.self) { taskGroup in
                 taskGroup.addTask {
                     do {
@@ -587,17 +587,25 @@ extension AsyncStream {
 
 @usableFromInline
 protocol TaskGroupProtocol {
-    mutating func addTask(operation: @escaping @Sendable () async -> Void)
+    // We need to call this `addTask_` because some Swift versions define this
+    // under exactly this name and others have different attributes. So let's pick
+    // a name that doesn't clash anywhere and implement it using the standard `addTask`.
+    mutating func addTask_(operation: @escaping @Sendable () async -> Void)
 }
 
 #if swift(>=5.8) && os(Linux) || swift(>=5.9)
 @available(macOS 14.0, iOS 17.0, tvOS 17.0, watchOS 10.0, *)
-extension DiscardingTaskGroup: TaskGroupProtocol {}
+extension DiscardingTaskGroup: TaskGroupProtocol {
+    @inlinable
+    mutating func addTask_(operation: @escaping @Sendable () async -> Void) {
+        self.addTask(priority: nil, operation: operation)
+    }
+}
 #endif
 
 extension TaskGroup<Void>: TaskGroupProtocol {
     @inlinable
-    mutating func addTask(operation: @escaping @Sendable () async -> Void) {
+    mutating func addTask_(operation: @escaping @Sendable () async -> Void) {
         self.addTask(priority: nil, operation: operation)
     }
 }

Tests/ConnectionPoolModuleTests/ConnectionPoolTests.swift

@@ -26,7 +26,7 @@ final class ConnectionPoolTests: XCTestCase {
         // the same connection is reused 1000 times
 
         await withTaskGroup(of: Void.self) { taskGroup in
-            taskGroup.addTask {
+            taskGroup.addTask_ {
                 await pool.run()
             }
 
@@ -82,14 +82,14 @@ final class ConnectionPoolTests: XCTestCase {
         }
 
         await withTaskGroup(of: Void.self) { taskGroup in
-            taskGroup.addTask {
+            taskGroup.addTask_ {
                 await pool.run()
             }
 
             let (blockCancelStream, blockCancelContinuation) = AsyncStream.makeStream(of: Void.self)
             let (blockConnCreationStream, blockConnCreationContinuation) = AsyncStream.makeStream(of: Void.self)
 
-            taskGroup.addTask {
+            taskGroup.addTask_ {
                 _ = try? await factory.nextConnectAttempt { _ in
                     blockCancelContinuation.yield()
                     var iterator = blockConnCreationStream.makeAsyncIterator()
@@ -127,7 +127,7 @@ final class ConnectionPoolTests: XCTestCase {
         }
 
         await withTaskGroup(of: Void.self) { taskGroup in
-            taskGroup.addTask {
+            taskGroup.addTask_ {
                 await pool.run()
             }
 
@@ -170,12 +170,12 @@ final class ConnectionPoolTests: XCTestCase {
         // the same connection is reused 1000 times
 
         await withTaskGroup(of: Void.self) { taskGroup in
-            taskGroup.addTask {
+            taskGroup.addTask_ {
                 await pool.run()
                 XCTAssertFalse(hasFinished.compareExchange(expected: false, desired: true, ordering: .relaxed).original)
             }
 
-            taskGroup.addTask {
+            taskGroup.addTask_ {
                 var usedConnectionIDs = Set<Int>()
                 for _ in 0..<config.maximumConnectionHardLimit {
                     await factory.nextConnectAttempt { connectionID in
@@ -192,7 +192,7 @@ final class ConnectionPoolTests: XCTestCase {
             let (stream, continuation) = AsyncStream.makeStream(of: Void.self)
 
             for _ in 0..<iterations {
-                taskGroup.addTask {
+                taskGroup.addTask_ {
                     do {
                         let leasedConnection = try await pool.leaseConnection()
                         pool.releaseConnection(leasedConnection)