Fix LMOVE empty source array bug (#185)

* Fix LMOVE empty source array bug

Signed-off-by: Annalise Mariottini <[email protected]>

* Override LMOVE Response in code generator

Signed-off-by: Adam Fowler <[email protected]>

---------

Signed-off-by: Annalise Mariottini <[email protected]>
Signed-off-by: Adam Fowler <[email protected]>
Co-authored-by: Adam Fowler <[email protected]>

Author: aim2120

Sources/Valkey/Commands/Custom/ListCustomCommands.swift

@@ -6,6 +6,12 @@
 // SPDX-License-Identifier: Apache-2.0
 //
 
+import NIOCore
+
+extension LMOVE {
+    public typealias Response = ByteBuffer?
+}
+
 extension LMPOP {
     /// - Returns: One of the following
     ///     * [Null]: If no element could be popped.

Sources/Valkey/Commands/ListCommands.swift

@@ -312,7 +312,6 @@ public struct LMOVE: ValkeyCommand {
             }
         }
     }
-    public typealias Response = ByteBuffer
 
     @inlinable public static var name: String { "LMOVE" }
 
@@ -794,7 +793,7 @@ extension ValkeyClientProtocol {
     /// - Response: [String]: The element being popped and pushed.
     @inlinable
     @discardableResult
-    public func lmove(source: ValkeyKey, destination: ValkeyKey, wherefrom: LMOVE.Wherefrom, whereto: LMOVE.Whereto) async throws -> ByteBuffer {
+    public func lmove(source: ValkeyKey, destination: ValkeyKey, wherefrom: LMOVE.Wherefrom, whereto: LMOVE.Whereto) async throws -> LMOVE.Response {
         try await execute(LMOVE(source: source, destination: destination, wherefrom: wherefrom, whereto: whereto))
     }
 

Sources/_ValkeyCommandsBuilder/ValkeyCommandsRender.swift

@@ -16,6 +16,7 @@ private let disableResponseCalculationCommands: Set<String> = [
     "GEOPOS",
     "GEOSEARCH",
     "ROLE",
+    "LMOVE",
     "LMPOP",
     "SPOP",
     "SSCAN",

Tests/IntegrationTests/ValkeyTests.swift

@@ -361,6 +361,38 @@ struct GeneratedCommands {
         }
     }
 
+    @available(valkeySwift 1.0, *)
+    @Test
+    func testLMOVE() async throws {
+        var logger = Logger(label: "Valkey")
+        logger.logLevel = .trace
+        try await withValkeyConnection(.hostname(valkeyHostname, port: 6379), logger: logger) { connection in
+            try await withKey(connection: connection) { key in
+                try await withKey(connection: connection) { key2 in
+                    let rtEmpty = try await connection.lmove(source: key, destination: key2, wherefrom: .right, whereto: .left)
+                    #expect(rtEmpty == nil)
+                    try await connection.lpush(key, elements: ["a"])
+                    try await connection.lpush(key, elements: ["b"])
+                    try await connection.lpush(key, elements: ["c"])
+                    try await connection.lpush(key, elements: ["d"])
+                    let list1Before = try await connection.lrange(key, start: 0, stop: -1).decode(as: [String].self)
+                    #expect(list1Before == ["d", "c", "b", "a"])
+                    let list2Before = try await connection.lrange(key2, start: 0, stop: -1).decode(as: [String].self)
+                    #expect(list2Before == [])
+                    for expectedValue in ["a", "b", "c", "d"] {
+                        var rt = try #require(try await connection.lmove(source: key, destination: key2, wherefrom: .right, whereto: .left))
+                        let value = rt.readString(length: 1)
+                        #expect(value == expectedValue)
+                    }
+                    let list1After = try await connection.lrange(key, start: 0, stop: -1).decode(as: [String].self)
+                    #expect(list1After == [])
+                    let list2After = try await connection.lrange(key2, start: 0, stop: -1).decode(as: [String].self)
+                    #expect(list2After == ["d", "c", "b", "a"])
+                }
+            }
+        }
+    }
+
     @available(valkeySwift 1.0, *)
     @Test("Test command error is thrown")
     func testCommandError() async throws {