From 2020d6ba6c5b4fefe6a325b530f680220ad8ae47 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Fri, 1 Aug 2025 10:48:04 +0400
Subject: [PATCH 01/15] return HTTP accepted on error

---
 Sources/AWSLambdaRuntime/Lambda+LocalServer.swift | 2 +-
 Sources/MockServer/MockHTTPServer.swift           | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda+LocalServer.swift b/Sources/AWSLambdaRuntime/Lambda+LocalServer.swift
index f536e3f4..86069aad 100644
--- a/Sources/AWSLambdaRuntime/Lambda+LocalServer.swift
+++ b/Sources/AWSLambdaRuntime/Lambda+LocalServer.swift
@@ -452,7 +452,7 @@ internal struct LambdaHTTPServer {
             await self.responsePool.push(
                 LocalServerResponse(
                     id: requestId,
-                    status: .ok,
+                    status: .accepted,
                     // the local server has no mecanism to collect headers set by the lambda function
                     headers: HTTPHeaders(),
                     body: body,
diff --git a/Sources/MockServer/MockHTTPServer.swift b/Sources/MockServer/MockHTTPServer.swift
index 78685c52..92fd297f 100644
--- a/Sources/MockServer/MockHTTPServer.swift
+++ b/Sources/MockServer/MockHTTPServer.swift
@@ -224,7 +224,7 @@ struct HttpServer {
         } else if requestHead.uri.hasSuffix("/response") {
             responseStatus = .accepted
         } else if requestHead.uri.hasSuffix("/error") {
-            responseStatus = .ok
+            responseStatus = .accepted
         } else {
             responseStatus = .notFound
         }

From 6e01c6ef85b12d38632ae349ed6971f5774c3fa4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Fri, 1 Aug 2025 11:16:54 +0400
Subject: [PATCH 02/15] force exit() when we loose connection to Lambda service

---
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index a1afb464..1962478f 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -330,6 +330,8 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                     try channel.pipeline.syncOperations.addHTTPClientHandlers()
                     // Lambda quotas... An invocation payload is maximal 6MB in size:
                     //   https://docs.aws.amazon.com/lambda/latest/dg/gettingstarted-limits.html
+                    // TODO: should we enforce this here ?  What about streaming functions that
+                    //       support up to 20Mb responses ?
                     try channel.pipeline.syncOperations.addHandler(
                         NIOHTTPClientResponseAggregator(maxContentLength: 6 * 1024 * 1024)
                     )
@@ -364,6 +366,14 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             channel.closeFuture.whenComplete { result in
                 self.assumeIsolated { runtimeClient in
                     runtimeClient.channelClosed(channel)
+
+                    // at this stage, we lost the connection to the Lambda Service,
+                    // this is very unlikely to happen when running in a lambda function deployed in the cloud
+                    // however, this happens when performance testing against the MockServer
+                    // shutdown this runtime.
+                    // The Lambda service will create a new runtime environment anyway
+                    runtimeClient.logger.trace("Connection to Lambda API lost, exiting")
+                    exit(-1)
                 }
             }
 

From 166cd461de8f595da9af1d33be4e2d601ab392a4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Sun, 3 Aug 2025 18:54:23 +0200
Subject: [PATCH 03/15] propagate the connection closed info through a Future

---
 Sources/AWSLambdaRuntime/Lambda.swift                | 12 ++++++++++++
 .../LambdaRuntime+ServiceLifecycle.swift             | 10 ++++++++--
 Sources/AWSLambdaRuntime/LambdaRuntime.swift         |  8 +++++++-
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift   | 10 ++++++++--
 4 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index 5412c139..ae8ca78a 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -41,6 +41,17 @@ public enum Lambda {
         var logger = logger
         do {
             while !Task.isCancelled {
+
+                if let runtimeClient = runtimeClient as? LambdaRuntimeClient,
+                    let futureConnectionClosed = await runtimeClient.futureConnectionClosed
+                {
+                    // Wait for the futureConnectionClosed to complete,
+                    // which will happen when the Lambda HTTP Server (or MockServer) closes the connection
+                    // This allows us to exit the run loop gracefully.
+                    // The futureConnectionClosed is always an error, let it throw to finish the run loop.
+                    let _ = try await futureConnectionClosed.get()
+                }
+
                 let (invocation, writer) = try await runtimeClient.nextInvocation()
                 logger[metadataKey: "aws-request-id"] = "\(invocation.metadata.requestID)"
 
@@ -84,6 +95,7 @@ public enum Lambda {
         } catch is CancellationError {
             // don't allow cancellation error to propagate further
         }
+
     }
 
     /// The default EventLoop the Lambda is scheduled on.
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
index 1b05b1c2..eb3e210e 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
@@ -17,8 +17,14 @@ import ServiceLifecycle
 
 extension LambdaRuntime: Service {
     public func run() async throws {
-        try await cancelWhenGracefulShutdown {
-            try await self._run()
+        await cancelWhenGracefulShutdown {
+            do {
+                try await self._run()
+            } catch {
+                // catch top level error that have not been handled before
+                // this avoids the runtime to crash and generate a backtrace
+                self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
+            }
         }
     }
 }
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime.swift b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
index 5f66df6f..7fc217a6 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
@@ -59,7 +59,13 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
     #if !ServiceLifecycleSupport
     @inlinable
     internal func run() async throws {
-        try await _run()
+        do {
+            try await _run()
+        } catch {
+            // catch top level error that have not been handled before
+            // this avoids the runtime to crash and generate a backtrace
+            self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
+        }
     }
     #endif
 
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index 1962478f..a54c534d 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -92,6 +92,9 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         case closed
     }
 
+    @usableFromInline
+    var futureConnectionClosed: EventLoopFuture<LambdaRuntimeError>? = nil
+
     private let eventLoop: any EventLoop
     private let logger: Logger
     private let configuration: Configuration
@@ -372,8 +375,10 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                     // however, this happens when performance testing against the MockServer
                     // shutdown this runtime.
                     // The Lambda service will create a new runtime environment anyway
-                    runtimeClient.logger.trace("Connection to Lambda API lost, exiting")
-                    exit(-1)
+                    runtimeClient.logger.trace("Connection to Lambda API. lost, exiting")
+                    runtimeClient.futureConnectionClosed = runtimeClient.eventLoop.makeFailedFuture(
+                        LambdaRuntimeError(code: .connectionToControlPlaneLost)
+                    )
                 }
             }
 
@@ -392,6 +397,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                 return handler
             }
         } catch {
+
             switch self.connectionState {
             case .disconnected, .connected:
                 fatalError("Unexpected state: \(self.connectionState)")

From a69ed54056867d823bc0c7263b17cfc70b8e954d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Sun, 3 Aug 2025 19:04:50 +0200
Subject: [PATCH 04/15] fix typos

---
 Sources/AWSLambdaRuntime/Lambda.swift                         | 2 +-
 Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift | 2 +-
 Sources/AWSLambdaRuntime/LambdaRuntime.swift                  | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index ae8ca78a..9b96f7ce 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -48,7 +48,7 @@ public enum Lambda {
                     // Wait for the futureConnectionClosed to complete,
                     // which will happen when the Lambda HTTP Server (or MockServer) closes the connection
                     // This allows us to exit the run loop gracefully.
-                    // The futureConnectionClosed is always an error, let it throw to finish the run loop.
+                    // The futureConnectionClosed is always an error, let it throw to terminate the Lambda run loop.
                     let _ = try await futureConnectionClosed.get()
                 }
 
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
index eb3e210e..90c4b060 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
@@ -21,7 +21,7 @@ extension LambdaRuntime: Service {
             do {
                 try await self._run()
             } catch {
-                // catch top level error that have not been handled before
+                // catch top level errors that have not been handled until now
                 // this avoids the runtime to crash and generate a backtrace
                 self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
             }
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime.swift b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
index 7fc217a6..9d4c3c8b 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
@@ -62,7 +62,7 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
         do {
             try await _run()
         } catch {
-            // catch top level error that have not been handled before
+            // catch top level errors that have not been handled until now
             // this avoids the runtime to crash and generate a backtrace
             self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
         }

From 04d9fc7cdce9a443533f6b1a178483285df8d1a8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Sun, 3 Aug 2025 20:07:09 +0200
Subject: [PATCH 05/15] fix unit tests

---
 Sources/AWSLambdaRuntime/Lambda.swift                    | 4 ++++
 .../LambdaRuntime+ServiceLifecycle.swift                 | 9 ++++++++-
 Sources/AWSLambdaRuntime/LambdaRuntime.swift             | 7 +++++++
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift       | 4 +---
 4 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index 9b96f7ce..b24d98fb 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -52,6 +52,7 @@ public enum Lambda {
                     let _ = try await futureConnectionClosed.get()
                 }
 
+                logger.trace("Waiting for next invocation")
                 let (invocation, writer) = try await runtimeClient.nextInvocation()
                 logger[metadataKey: "aws-request-id"] = "\(invocation.metadata.requestID)"
 
@@ -87,10 +88,13 @@ public enum Lambda {
                             logger: logger
                         )
                     )
+                    logger.trace("Handler finished processing invocation")
                 } catch {
+                    logger.trace("Handler failed processing invocation", metadata: ["Handler error": "\(error)"])
                     try await writer.reportError(error)
                     continue
                 }
+                logger.handler.metadata.removeValue(forKey: "aws-request-id")
             }
         } catch is CancellationError {
             // don't allow cancellation error to propagate further
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
index 90c4b060..50616df9 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
@@ -17,13 +17,20 @@ import ServiceLifecycle
 
 extension LambdaRuntime: Service {
     public func run() async throws {
-        await cancelWhenGracefulShutdown {
+        try await cancelWhenGracefulShutdown {
             do {
                 try await self._run()
             } catch {
                 // catch top level errors that have not been handled until now
                 // this avoids the runtime to crash and generate a backtrace
                 self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
+                if let error = error as? LambdaRuntimeError,
+                    error.code != .connectionToControlPlaneLost
+                {
+                    // if the error is a LambdaRuntimeError but not a connection error,
+                    // we rethrow it to preserve existing behaviour
+                    throw error
+                }
             }
         }
     }
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime.swift b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
index 9d4c3c8b..daa8ed5f 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
@@ -65,6 +65,13 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
             // catch top level errors that have not been handled until now
             // this avoids the runtime to crash and generate a backtrace
             self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
+            if let error = error as? LambdaRuntimeError,
+                error.code != .connectionToControlPlaneLost
+            {
+                // if the error is a LambdaRuntimeError but not a connection error,
+                // we rethrow it to preserve existing behaviour
+                throw error
+            }
         }
     }
     #endif
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index a54c534d..ece727ef 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -121,10 +121,8 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         } catch {
             result = .failure(error)
         }
-
         await runtime.close()
 
-        //try? await runtime.close()
         return try result.get()
     }
 
@@ -375,7 +373,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                     // however, this happens when performance testing against the MockServer
                     // shutdown this runtime.
                     // The Lambda service will create a new runtime environment anyway
-                    runtimeClient.logger.trace("Connection to Lambda API. lost, exiting")
+                    runtimeClient.logger.trace("Connection to Lambda Service HTTP Server lost, exiting")
                     runtimeClient.futureConnectionClosed = runtimeClient.eventLoop.makeFailedFuture(
                         LambdaRuntimeError(code: .connectionToControlPlaneLost)
                     )

From 025a0e59e31df9275d23b4e8ed41122d8c8d527f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 16:00:39 +0200
Subject: [PATCH 06/15] simplify by checking connection state in the
 `nextInvocation()` call

---
 Sources/AWSLambdaRuntime/Lambda.swift         | 16 +++-----
 .../LambdaRuntimeClient.swift                 | 39 ++++++++++++-------
 2 files changed, 31 insertions(+), 24 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index 80f862ce..f3edaccf 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -41,17 +41,13 @@ public enum Lambda {
         var logger = logger
         do {
             while !Task.isCancelled {
-
-                if let runtimeClient = runtimeClient as? LambdaRuntimeClient,
-                    let futureConnectionClosed = await runtimeClient.futureConnectionClosed
-                {
-                    // Wait for the futureConnectionClosed to complete,
-                    // which will happen when the Lambda HTTP Server (or MockServer) closes the connection
-                    // This allows us to exit the run loop gracefully.
-                    // The futureConnectionClosed is always an error, let it throw to terminate the Lambda run loop.
-                    let _ = try await futureConnectionClosed.get()
+                
+                guard let runtimeClient = runtimeClient as? LambdaRuntimeClient,
+                      await !runtimeClient.isConnectionStateDisconnected else {
+                    logger.trace("Runtime client not connected, exiting run loop")
+                    throw LambdaRuntimeError.init(code: .connectionToControlPlaneLost)
                 }
-
+                
                 logger.trace("Waiting for next invocation")
                 let (invocation, writer) = try await runtimeClient.nextInvocation()
                 logger[metadataKey: "aws-request-id"] = "\(invocation.metadata.requestID)"
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index ece727ef..e06d1732 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -67,10 +67,23 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         NIOLoopBound<LambdaChannelHandler<LambdaRuntimeClient>>, any Error
     >
 
-    private enum ConnectionState {
+    private enum ConnectionState: Equatable {
         case disconnected
         case connecting([ConnectionContinuation])
         case connected(Channel, LambdaChannelHandler<LambdaRuntimeClient>)
+        
+        static func == (lhs: ConnectionState, rhs: ConnectionState) -> Bool {
+            switch (lhs, rhs) {
+            case (.disconnected, .disconnected):
+                return true
+            case (.connecting, .connecting):
+                return true
+            case (.connected, .connected):
+                return true
+            default:
+                return false
+            }
+        }
     }
 
     enum LambdaState {
@@ -92,14 +105,22 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         case closed
     }
 
-    @usableFromInline
-    var futureConnectionClosed: EventLoopFuture<LambdaRuntimeError>? = nil
-
     private let eventLoop: any EventLoop
     private let logger: Logger
     private let configuration: Configuration
 
     private var connectionState: ConnectionState = .disconnected
+
+    // adding this dynamic property because I can not give access to `connectionState` directly
+    // because it is private, depending on multiple private and non-Sendable types
+    // the only thing we need to know outside of this class is if the connection state is disconnected
+    @usableFromInline
+    var isConnectionStateDisconnected: Bool {
+        get {
+            self.connectionState == .disconnected
+        }
+    }
+
     private var lambdaState: LambdaState = .idle(previousRequestID: nil)
     private var closingState: ClosingState = .notClosing
 
@@ -367,16 +388,6 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             channel.closeFuture.whenComplete { result in
                 self.assumeIsolated { runtimeClient in
                     runtimeClient.channelClosed(channel)
-
-                    // at this stage, we lost the connection to the Lambda Service,
-                    // this is very unlikely to happen when running in a lambda function deployed in the cloud
-                    // however, this happens when performance testing against the MockServer
-                    // shutdown this runtime.
-                    // The Lambda service will create a new runtime environment anyway
-                    runtimeClient.logger.trace("Connection to Lambda Service HTTP Server lost, exiting")
-                    runtimeClient.futureConnectionClosed = runtimeClient.eventLoop.makeFailedFuture(
-                        LambdaRuntimeError(code: .connectionToControlPlaneLost)
-                    )
                 }
             }
 

From ce8b5672aa4806a1d6d9f2652fed5452d15a5466 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 16:49:26 +0200
Subject: [PATCH 07/15] introducing a new connection state "lostConnection"

---
 Sources/AWSLambdaRuntime/Lambda.swift         |  4 ++--
 .../LambdaRuntimeClient.swift                 | 24 +++++++++++++++----
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index f3edaccf..683e3090 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -43,8 +43,8 @@ public enum Lambda {
             while !Task.isCancelled {
                 
                 guard let runtimeClient = runtimeClient as? LambdaRuntimeClient,
-                      await !runtimeClient.isConnectionStateDisconnected else {
-                    logger.trace("Runtime client not connected, exiting run loop")
+                      await !runtimeClient.didLooseConnection else {
+                    logger.trace("Runtime client disconnected, exiting run loop")
                     throw LambdaRuntimeError.init(code: .connectionToControlPlaneLost)
                 }
                 
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index e06d1732..d1900509 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -69,6 +69,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
 
     private enum ConnectionState: Equatable {
         case disconnected
+        case lostConnection
         case connecting([ConnectionContinuation])
         case connected(Channel, LambdaChannelHandler<LambdaRuntimeClient>)
         
@@ -80,6 +81,8 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                 return true
             case (.connected, .connected):
                 return true
+            case (.lostConnection, .lostConnection):
+                return true
             default:
                 return false
             }
@@ -115,9 +118,9 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
     // because it is private, depending on multiple private and non-Sendable types
     // the only thing we need to know outside of this class is if the connection state is disconnected
     @usableFromInline
-    var isConnectionStateDisconnected: Bool {
+    var didLooseConnection: Bool {
         get {
-            self.connectionState == .disconnected
+            self.connectionState == .lostConnection
         }
     }
 
@@ -179,12 +182,16 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
 
             case .connected(let channel, _):
                 channel.close(mode: .all, promise: nil)
+            case .lostConnection:
+                // this should never happen.
+                fatalError("Lost connection to Lambda service while closing the runtime client")
             }
         }
     }
 
     @usableFromInline
     func nextInvocation() async throws -> (Invocation, Writer) {
+
         try await withTaskCancellationHandler {
             switch self.lambdaState {
             case .idle:
@@ -284,7 +291,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
 
     private func channelClosed(_ channel: any Channel) {
         switch (self.connectionState, self.closingState) {
-        case (_, .closed):
+        case (_, .closed), (.lostConnection, _):
             fatalError("Invalid state: \(self.connectionState), \(self.closingState)")
 
         case (.disconnected, .notClosing):
@@ -344,6 +351,10 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             return loopBound.value
         case .connected(_, let handler):
             return handler
+
+        case .lostConnection:
+            // this should never happen
+            fatalError("Lost connection to Lambda service")
         }
 
         let bootstrap = ClientBootstrap(group: self.eventLoop)
@@ -392,7 +403,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             }
 
             switch self.connectionState {
-            case .disconnected, .connected:
+            case .disconnected, .connected, .lostConnection:
                 fatalError("Unexpected state: \(self.connectionState)")
 
             case .connecting(let array):
@@ -408,7 +419,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         } catch {
 
             switch self.connectionState {
-            case .disconnected, .connected:
+            case .disconnected, .connected, .lostConnection:
                 fatalError("Unexpected state: \(self.connectionState)")
 
             case .connecting(let array):
@@ -456,6 +467,9 @@ extension LambdaRuntimeClient: LambdaChannelHandlerDelegate {
 
                 isolated.connectionState = .disconnected
 
+            case .lostConnection:
+                // this should never happen
+                fatalError("Lost connection to Lambda service")
             }
         }
     }

From be4cb20bf1d0fc656a4ffa56258a528e995d3e3f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 16:58:10 +0200
Subject: [PATCH 08/15] add state change

---
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index d1900509..eef8cbcd 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -399,6 +399,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             channel.closeFuture.whenComplete { result in
                 self.assumeIsolated { runtimeClient in
                     runtimeClient.channelClosed(channel)
+                    runtimeClient.connectionState = .lostConnection
                 }
             }
 

From b37ea0ee389fafa16d5ab8181900fd68b27753cf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:26:42 +0200
Subject: [PATCH 09/15] fix lost continuation

---
 Sources/AWSLambdaRuntime/Lambda.swift         |  6 ---
 .../LambdaRuntimeClient.swift                 | 46 ++++++++++++-------
 .../AWSLambdaRuntime/LambdaRuntimeError.swift |  1 -
 3 files changed, 29 insertions(+), 24 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index 683e3090..042d9c6f 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -42,12 +42,6 @@ public enum Lambda {
         do {
             while !Task.isCancelled {
                 
-                guard let runtimeClient = runtimeClient as? LambdaRuntimeClient,
-                      await !runtimeClient.didLooseConnection else {
-                    logger.trace("Runtime client disconnected, exiting run loop")
-                    throw LambdaRuntimeError.init(code: .connectionToControlPlaneLost)
-                }
-                
                 logger.trace("Waiting for next invocation")
                 let (invocation, writer) = try await runtimeClient.nextInvocation()
                 logger[metadataKey: "aws-request-id"] = "\(invocation.metadata.requestID)"
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index eef8cbcd..e0366a77 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -114,16 +114,6 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
 
     private var connectionState: ConnectionState = .disconnected
 
-    // adding this dynamic property because I can not give access to `connectionState` directly
-    // because it is private, depending on multiple private and non-Sendable types
-    // the only thing we need to know outside of this class is if the connection state is disconnected
-    @usableFromInline
-    var didLooseConnection: Bool {
-        get {
-            self.connectionState == .lostConnection
-        }
-    }
-
     private var lambdaState: LambdaState = .idle(previousRequestID: nil)
     private var closingState: ClosingState = .notClosing
 
@@ -146,7 +136,6 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             result = .failure(error)
         }
         await runtime.close()
-
         return try result.get()
     }
 
@@ -182,9 +171,9 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
 
             case .connected(let channel, _):
                 channel.close(mode: .all, promise: nil)
+            
             case .lostConnection:
-                // this should never happen.
-                fatalError("Lost connection to Lambda service while closing the runtime client")
+                continuation.resume()
             }
         }
     }
@@ -192,12 +181,17 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
     @usableFromInline
     func nextInvocation() async throws -> (Invocation, Writer) {
 
-        try await withTaskCancellationHandler {
+        if self.connectionState == .lostConnection {
+            throw LambdaRuntimeError(code: .connectionToControlPlaneLost)
+        }
+
+        return try await withTaskCancellationHandler {
             switch self.lambdaState {
             case .idle:
                 self.lambdaState = .waitingForNextInvocation
                 let handler = try await self.makeOrGetConnection()
                 let invocation = try await handler.nextInvocation()
+                                
                 guard case .waitingForNextInvocation = self.lambdaState else {
                     fatalError("Invalid state: \(self.lambdaState)")
                 }
@@ -312,7 +306,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         case (.connecting(let array), .notClosing):
             self.connectionState = .disconnected
             for continuation in array {
-                continuation.resume(throwing: LambdaRuntimeError(code: .lostConnectionToControlPlane))
+                continuation.resume(throwing: LambdaRuntimeError(code: .connectionToControlPlaneLost))
             }
 
         case (.connecting(let array), .closing(let continuation)):
@@ -326,6 +320,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         case (.connected, .notClosing):
             self.connectionState = .disconnected
 
+
         case (.connected, .closing(let continuation)):
             self.connectionState = .disconnected
 
@@ -398,13 +393,24 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             )
             channel.closeFuture.whenComplete { result in
                 self.assumeIsolated { runtimeClient in
+
+                    // resume any pending continuation on the handler
+                    if case .connected(_ , let handler) = runtimeClient.connectionState {
+                        if case .connected(_ , let lambdaState) = handler.state {
+                            if case .waitingForNextInvocation(let continuation) = lambdaState {
+                                continuation.resume(throwing: LambdaRuntimeError(code: .connectionToControlPlaneLost))
+                            }
+                        }
+                    }
+
+                    // close the channel
                     runtimeClient.channelClosed(channel)
                     runtimeClient.connectionState = .lostConnection
                 }
             }
 
             switch self.connectionState {
-            case .disconnected, .connected, .lostConnection:
+            case .disconnected, .connected:
                 fatalError("Unexpected state: \(self.connectionState)")
 
             case .connecting(let array):
@@ -416,11 +422,14 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                     }
                 }
                 return handler
+            case .lostConnection:
+                // this should never happen
+                fatalError("Lost connection to Lambda service")
             }
         } catch {
 
             switch self.connectionState {
-            case .disconnected, .connected, .lostConnection:
+            case .disconnected, .connected:
                 fatalError("Unexpected state: \(self.connectionState)")
 
             case .connecting(let array):
@@ -431,6 +440,9 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                     }
                 }
                 throw error
+            case .lostConnection:
+                // this should never happen
+                fatalError("Lost connection to Lambda service")
             }
         }
     }
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeError.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeError.swift
index a9c0cbca..bc4865db 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeError.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeError.swift
@@ -25,7 +25,6 @@ package struct LambdaRuntimeError: Error {
 
         case writeAfterFinishHasBeenSent
         case finishAfterFinishHasBeenSent
-        case lostConnectionToControlPlane
         case unexpectedStatusCodeForRequest
 
         case nextInvocationMissingHeaderRequestID

From cd0094823fcb54277bd0d682ea756ead78e066b0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:32:46 +0200
Subject: [PATCH 10/15] fix compilation error

---
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index e0366a77..27eb74ea 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -515,7 +515,7 @@ private final class LambdaChannelHandler<Delegate: LambdaChannelHandlerDelegate>
         }
     }
 
-    private var state: State = .disconnected
+    var state: State = .disconnected
     private var lastError: Error?
     private var reusableErrorBuffer: ByteBuffer?
     private let logger: Logger

From 008c54246390ae45ace08ba8b0860649958fc5f5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:33:06 +0200
Subject: [PATCH 11/15] DRY: move the error handling to the _run() function

---
 .../LambdaRuntime+ServiceLifecycle.swift      | 15 +---------
 Sources/AWSLambdaRuntime/LambdaRuntime.swift  | 28 +++++++++----------
 2 files changed, 15 insertions(+), 28 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
index 50616df9..1b05b1c2 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime+ServiceLifecycle.swift
@@ -18,20 +18,7 @@ import ServiceLifecycle
 extension LambdaRuntime: Service {
     public func run() async throws {
         try await cancelWhenGracefulShutdown {
-            do {
-                try await self._run()
-            } catch {
-                // catch top level errors that have not been handled until now
-                // this avoids the runtime to crash and generate a backtrace
-                self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
-                if let error = error as? LambdaRuntimeError,
-                    error.code != .connectionToControlPlaneLost
-                {
-                    // if the error is a LambdaRuntimeError but not a connection error,
-                    // we rethrow it to preserve existing behaviour
-                    throw error
-                }
-            }
+            try await self._run()
         }
     }
 }
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime.swift b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
index daa8ed5f..4d7450e5 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
@@ -59,20 +59,7 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
     #if !ServiceLifecycleSupport
     @inlinable
     internal func run() async throws {
-        do {
-            try await _run()
-        } catch {
-            // catch top level errors that have not been handled until now
-            // this avoids the runtime to crash and generate a backtrace
-            self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
-            if let error = error as? LambdaRuntimeError,
-                error.code != .connectionToControlPlaneLost
-            {
-                // if the error is a LambdaRuntimeError but not a connection error,
-                // we rethrow it to preserve existing behaviour
-                throw error
-            }
-        }
+        try await _run()
     }
     #endif
 
@@ -107,6 +94,7 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
             let ip = String(ipAndPort[0])
             guard let port = Int(ipAndPort[1]) else { throw LambdaRuntimeError(code: .invalidPort) }
 
+            do {
             try await LambdaRuntimeClient.withRuntimeClient(
                 configuration: .init(ip: ip, port: port),
                 eventLoop: self.eventLoop,
@@ -118,6 +106,18 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
                     logger: self.logger
                 )
             }
+        } catch {
+            // catch top level errors that have not been handled until now
+            // this avoids the runtime to crash and generate a backtrace
+            self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
+            if let error = error as? LambdaRuntimeError,
+                error.code != .connectionToControlPlaneLost
+            {
+                // if the error is a LambdaRuntimeError but not a connection error,
+                // we rethrow it to preserve existing behaviour
+                throw error
+            }
+        }
 
         } else {
 

From 9dcb4b33115b0667a2f1a6542e5215c30237dd2a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:51:33 +0200
Subject: [PATCH 12/15] fix a case where continuation was resumed twice

---
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index 27eb74ea..ff03e329 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -937,6 +937,7 @@ extension LambdaChannelHandler: ChannelInboundHandler {
         // fail any pending responses with last error or assume peer disconnected
         switch self.state {
         case .connected(_, .waitingForNextInvocation(let continuation)):
+            self.state = .disconnected
             continuation.resume(throwing: self.lastError ?? ChannelError.ioOnClosedChannel)
         default:
             break

From f2d94a2b5c68f4ad45b1292c7f391071f098a204 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:52:45 +0200
Subject: [PATCH 13/15] fix unit test

---
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index ff03e329..a0898971 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -348,8 +348,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
             return handler
 
         case .lostConnection:
-            // this should never happen
-            fatalError("Lost connection to Lambda service")
+            throw LambdaRuntimeError(code: .connectionToControlPlaneLost)
         }
 
         let bootstrap = ClientBootstrap(group: self.eventLoop)

From 852391e51635c23f21bda3705ac2a997c28e935b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:53:11 +0200
Subject: [PATCH 14/15] swift format

---
 Sources/AWSLambdaRuntime/Lambda.swift         |  2 +-
 Sources/AWSLambdaRuntime/LambdaRuntime.swift  | 42 +++++++++----------
 .../LambdaRuntimeClient.swift                 | 11 +++--
 3 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/Lambda.swift b/Sources/AWSLambdaRuntime/Lambda.swift
index 042d9c6f..f6223cb5 100644
--- a/Sources/AWSLambdaRuntime/Lambda.swift
+++ b/Sources/AWSLambdaRuntime/Lambda.swift
@@ -41,7 +41,7 @@ public enum Lambda {
         var logger = logger
         do {
             while !Task.isCancelled {
-                
+
                 logger.trace("Waiting for next invocation")
                 let (invocation, writer) = try await runtimeClient.nextInvocation()
                 logger[metadataKey: "aws-request-id"] = "\(invocation.metadata.requestID)"
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntime.swift b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
index 4d7450e5..a639ac31 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntime.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntime.swift
@@ -95,29 +95,29 @@ public final class LambdaRuntime<Handler>: Sendable where Handler: StreamingLamb
             guard let port = Int(ipAndPort[1]) else { throw LambdaRuntimeError(code: .invalidPort) }
 
             do {
-            try await LambdaRuntimeClient.withRuntimeClient(
-                configuration: .init(ip: ip, port: port),
-                eventLoop: self.eventLoop,
-                logger: self.logger
-            ) { runtimeClient in
-                try await Lambda.runLoop(
-                    runtimeClient: runtimeClient,
-                    handler: handler,
+                try await LambdaRuntimeClient.withRuntimeClient(
+                    configuration: .init(ip: ip, port: port),
+                    eventLoop: self.eventLoop,
                     logger: self.logger
-                )
-            }
-        } catch {
-            // catch top level errors that have not been handled until now
-            // this avoids the runtime to crash and generate a backtrace
-            self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
-            if let error = error as? LambdaRuntimeError,
-                error.code != .connectionToControlPlaneLost
-            {
-                // if the error is a LambdaRuntimeError but not a connection error,
-                // we rethrow it to preserve existing behaviour
-                throw error
+                ) { runtimeClient in
+                    try await Lambda.runLoop(
+                        runtimeClient: runtimeClient,
+                        handler: handler,
+                        logger: self.logger
+                    )
+                }
+            } catch {
+                // catch top level errors that have not been handled until now
+                // this avoids the runtime to crash and generate a backtrace
+                self.logger.error("LambdaRuntime.run() failed with error", metadata: ["error": "\(error)"])
+                if let error = error as? LambdaRuntimeError,
+                    error.code != .connectionToControlPlaneLost
+                {
+                    // if the error is a LambdaRuntimeError but not a connection error,
+                    // we rethrow it to preserve existing behaviour
+                    throw error
+                }
             }
-        }
 
         } else {
 
diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index a0898971..40f84f89 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -72,7 +72,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         case lostConnection
         case connecting([ConnectionContinuation])
         case connected(Channel, LambdaChannelHandler<LambdaRuntimeClient>)
-        
+
         static func == (lhs: ConnectionState, rhs: ConnectionState) -> Bool {
             switch (lhs, rhs) {
             case (.disconnected, .disconnected):
@@ -171,7 +171,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
 
             case .connected(let channel, _):
                 channel.close(mode: .all, promise: nil)
-            
+
             case .lostConnection:
                 continuation.resume()
             }
@@ -191,7 +191,7 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                 self.lambdaState = .waitingForNextInvocation
                 let handler = try await self.makeOrGetConnection()
                 let invocation = try await handler.nextInvocation()
-                                
+
                 guard case .waitingForNextInvocation = self.lambdaState else {
                     fatalError("Invalid state: \(self.lambdaState)")
                 }
@@ -320,7 +320,6 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
         case (.connected, .notClosing):
             self.connectionState = .disconnected
 
-
         case (.connected, .closing(let continuation)):
             self.connectionState = .disconnected
 
@@ -394,8 +393,8 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                 self.assumeIsolated { runtimeClient in
 
                     // resume any pending continuation on the handler
-                    if case .connected(_ , let handler) = runtimeClient.connectionState {
-                        if case .connected(_ , let lambdaState) = handler.state {
+                    if case .connected(_, let handler) = runtimeClient.connectionState {
+                        if case .connected(_, let lambdaState) = handler.state {
                             if case .waitingForNextInvocation(let continuation) = lambdaState {
                                 continuation.resume(throwing: LambdaRuntimeError(code: .connectionToControlPlaneLost))
                             }

From b13bf5cfa0bf5c28c6eb0a31a3218a48f4a26537 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Stormacq?= <sebastien.stormacq@gmail.com>
Date: Thu, 7 Aug 2025 23:59:23 +0200
Subject: [PATCH 15/15] remove comment on max payload size

---
 Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
index 40f84f89..008b9b42 100644
--- a/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
+++ b/Sources/AWSLambdaRuntime/LambdaRuntimeClient.swift
@@ -356,8 +356,6 @@ final actor LambdaRuntimeClient: LambdaRuntimeClientProtocol {
                     try channel.pipeline.syncOperations.addHTTPClientHandlers()
                     // Lambda quotas... An invocation payload is maximal 6MB in size:
                     //   https://docs.aws.amazon.com/lambda/latest/dg/gettingstarted-limits.html
-                    // TODO: should we enforce this here ?  What about streaming functions that
-                    //       support up to 20Mb responses ?
                     try channel.pipeline.syncOperations.addHandler(
                         NIOHTTPClientResponseAggregator(maxContentLength: 6 * 1024 * 1024)
                     )