Support 'GET' option in 'SET' command

modules/redis/src/main/scala/zio/redis/Input.scala

@@ -260,6 +260,11 @@ object Input {
       RespCommand(RespCommandArgument.Literal("FREQ"), RespCommandArgument.Unknown(data.frequency))
   }
 
+  case object GetKeywordInput extends Input[GetKeyword] {
+    def encode(data: GetKeyword): RespCommand =
+      RespCommand(RespCommandArgument.Literal(data.asString))
+  }
+
   case object IdleTimeInput extends Input[IdleTime] {
     def encode(data: IdleTime): RespCommand =
       RespCommand(RespCommandArgument.Literal("IDLETIME"), RespCommandArgument.Unknown(data.seconds.toString))

modules/redis/src/main/scala/zio/redis/api/Strings.scala

@@ -523,6 +523,42 @@ trait Strings extends RedisEnvironment {
     command.run((key, expiration, value))
   }
 
+  /**
+   * Set the string value of a key with a 'GET' option.
+   *
+   * @param key
+   *   Key of the string to set
+   * @param value
+   *   Value to set
+   * @param expireTime
+   *   Time until the string expires
+   * @param update
+   *   Update can be Update.SetExisting which only sets the key if it exists, or Update.SetNew which nly sets the key if
+   *   it does not exist
+   * @param keepTtl
+   *   When set any previously set expire time remains unchanged
+   * @return
+   *   the old value stored at key, or None if key did not exist
+   */
+  final def setGet[K: Schema, V: Schema](
+    key: K,
+    value: V,
+    expireTime: Option[Duration] = None,
+    update: Option[Update] = None,
+    keepTtl: Option[KeepTtl] = None
+  ): IO[RedisError, Option[V]] = {
+    val input = Tuple6(
+      ArbitraryKeyInput[K](),
+      ArbitraryValueInput[V](),
+      OptionalInput(DurationTtlInput),
+      OptionalInput(UpdateInput),
+      OptionalInput(KeepTtlInput),
+      GetKeywordInput
+    )
+    val command = RedisCommand(Set, input, OptionalOutput(ArbitraryOutput[V]()), executor)
+    command.run((key, value, expireTime, update, keepTtl, GetKeyword))
+  }
+
   /**
    * Set the value of a key, only if the key does not exist.
    *
@@ -543,7 +579,7 @@ trait Strings extends RedisEnvironment {
    * Overwrite part of a string at key starting at the specified offset.
    *
    * @param key
-   *   Key of the string to overwite
+   *   Key of the string to overwrite
    * @param offset
    *   Offset to start writing
    * @param value

modules/redis/src/main/scala/zio/redis/options/Strings.scala

@@ -118,6 +118,7 @@ trait Strings {
         case Expire.SetExpireMilliseconds => "PX"
       }
   }
+
   object Expire {
     case object SetExpireSeconds      extends Expire
     case object SetExpireMilliseconds extends Expire
@@ -130,8 +131,15 @@ trait Strings {
         case ExpiredAt.SetExpireAtMilliseconds => "PXAT"
       }
   }
+
   object ExpiredAt {
     case object SetExpireAtSeconds      extends ExpiredAt
     case object SetExpireAtMilliseconds extends ExpiredAt
   }
+
+  case object GetKeyword {
+    private[redis] def asString: String = "GET"
+  }
+
+  type GetKeyword = GetKeyword.type
 }

modules/redis/src/test/scala/zio/redis/InputSpec.scala

@@ -450,6 +450,13 @@ object InputSpec extends BaseSpec {
           } yield assert(result)(equalTo(RespCommand(Literal("GET"), Unknown("mypattern_*"))))
         }
       ),
+      suite("GetKeyword")(
+        test("valid value") {
+          for {
+            result <- ZIO.attempt(GetKeywordInput.encode(GetKeyword))
+          } yield assert(result)(equalTo(RespCommand(Literal("GET"))))
+        }
+      ),
       suite("IdleTime")(
         test("0 seconds") {
           for {

modules/redis/src/test/scala/zio/redis/KeysSpec.scala

@@ -18,6 +18,24 @@ trait KeysSpec extends BaseSpec {
           v     <- redis.get(key).returning[String]
         } yield assert(v)(isSome(equalTo(value)))
       },
+      test("setGet with non-existing key") {
+        for {
+          redis <- ZIO.service[Redis]
+          key   <- uuid
+          value <- uuid
+          v     <- redis.setGet(key, value)
+        } yield assert(v)(isNone)
+      },
+      test("setGet with the existing key") {
+        for {
+          redis    <- ZIO.service[Redis]
+          value    <- uuid
+          key      <- uuid
+          _        <- redis.set(key, value)
+          newValue <- uuid
+          v        <- redis.setGet(key, newValue)
+        } yield assert(v)(isSome(equalTo(value)))
+      },
       test("get non-existing key") {
         for {
           redis <- ZIO.service[Redis]