Merge branch 'unselect'

.swiftpm/xcode/xcshareddata/xcschemes/SwiftIMAPCLI.xcscheme

@@ -55,7 +55,7 @@
          <EnvironmentVariable
             key = "ENABLE_DEBUG_OUTPUT"
             value = "1"
-            isEnabled = "NO">
+            isEnabled = "YES">
          </EnvironmentVariable>
       </EnvironmentVariables>
    </LaunchAction>

Implemented.md

@@ -37,7 +37,7 @@
 - [x] COPY - Copy messages to another mailbox.
 - [x] MOVE - Move messages to another mailbox.
 - [x] EXPUNGE - Expunge deleted messages from the selected mailbox.
-- [ ] UNSELECT - Allows the client to unselect the current mailbox without selecting a new one.
+- [x] UNSELECT - Allows the client to unselect the current mailbox without selecting a new one.
 
 #### Message Commands
 

Sources/SwiftIMAP/IMAP/Commands/UnselectCommand.swift

@@ -0,0 +1,30 @@
+import Foundation
+import NIOIMAPCore
+
+/**
+ Command to unselect the currently selected mailbox without expunging deleted messages
+
+ The UNSELECT command is an extension to the core IMAP protocol defined in RFC 3691.
+ It allows a client to deselect the current mailbox without implicitly causing an expunge 
+ of messages marked for deletion, as the CLOSE command does.
+ */
+public struct UnselectCommand: IMAPCommand {
+    public typealias ResultType = Void
+    public typealias HandlerType = UnselectHandler
+
+    public var handlerType: HandlerType.Type {
+        return UnselectHandler.self
+    }
+
+    public init() {}
+
+    public func validate() throws {
+        // No validation needed for UNSELECT command
+    }
+
+    public func toTaggedCommand(tag: String) -> TaggedCommand {
+        // Using a raw string command since UNSELECT is not in the standard Command enum
+        // The UNSELECT command takes no parameters
+		return TaggedCommand(tag: tag, command: .unselect)
+    }
+} 

Sources/SwiftIMAP/IMAP/Handler/UnselectHandler.swift

@@ -0,0 +1,41 @@
+import Foundation
+import NIOIMAPCore
+import NIO
+import Logging
+
+/**
+ Handler for the UNSELECT command
+
+ This handler processes responses from the IMAP server to the UNSELECT command.
+ The UNSELECT command is an extension to IMAP defined in RFC 3691 that allows
+ a client to deselect the current mailbox without expunging deleted messages.
+ */
+public final class UnselectHandler: BaseIMAPCommandHandler<Void>, IMAPCommandHandler {
+    public typealias ResultType = Void
+    public typealias InboundIn = Response
+    public typealias InboundOut = Never
+
+    override public func processResponse(_ response: Response) -> Bool {
+        // Call the base class implementation to buffer the response
+        let handled = super.processResponse(response)
+
+        // Process the response
+        if case .tagged(let tagged) = response, tagged.tag == commandTag {
+            // This is our tagged response, handle it
+            switch tagged.state {
+                case .ok:
+                    // UNSELECT succeeded
+                    succeedWithResult(())
+                case .no(let text):
+                    // UNSELECT failed with NO response
+                    failWithError(IMAPError.commandFailed("NO response: \(text)"))
+                case .bad(let text):
+                    // UNSELECT failed with BAD response (likely not supported)
+                    failWithError(IMAPError.commandFailed("BAD response: \(text)"))
+            }
+            return true
+        }
+
+        return handled
+    }
+} 

Sources/SwiftIMAP/IMAPError.swift

@@ -19,6 +19,7 @@ public enum IMAPError: Error {
     case storeFailed(String)
     case expungeFailed(String)
     case moveFailed(String)
+    case commandNotSupported(String)
 }
 
 // Add CustomStringConvertible conformance for better error messages
@@ -53,6 +54,8 @@ extension IMAPError: CustomStringConvertible {
             return "Expunge failed: \(reason)"
         case .moveFailed(let reason):
             return "Move failed: \(reason)"
+        case .commandNotSupported(let reason):
+            return "Command not supported: \(reason)"
         }
     }
 } 

Sources/SwiftIMAP/IMAPServer.swift

@@ -212,6 +212,24 @@ public actor IMAPServer {
 		try await executeCommand(command)
 	}
 
+	/**
+	 Unselect the currently selected mailbox without expunging deleted messages
+
+	 This is an IMAP extension command (RFC 3691) that might not be supported by all servers.
+	 If the server does not support UNSELECT, an IMAPError will be thrown.
+
+	 - Throws: An error if the unselect operation fails or is not supported
+	 */
+	public func unselectMailbox() async throws {
+		// Check if the server supports UNSELECT capability
+		if !capabilities.contains(.unselect) {
+			throw IMAPError.commandNotSupported("UNSELECT command not supported by server")
+		}
+
+		let command = UnselectCommand()
+		try await executeCommand(command)
+	}
+
 	/**
 	 Logout from the IMAP server
 	 - Throws: An error if the logout fails