added LPUSH command

2 files changed, 39 insertions, 0 deletions

diff --git a/handlers.go b/handlers.go
index 5bf16a8..3b7fb76 100644
--- a/handlers.go
+++ b/handlers.go
@@ -200,6 +200,12 @@ func handleRpush(conn net.Conn, args []string) {
 	key := args[1]
 	newItems := args[2:]
 
+	if len(args) < 3 {
+        err := errors.New("wrong number of arguments for 'RPUSH'")
+        conn.Write(serializeRESP(err))
+		return
+    }
+
 	db.mu.Lock()
 	defer db.mu.Unlock()
 
@@ -222,6 +228,38 @@ func handleRpush(conn net.Conn, args []string) {
 	conn.Write(serializeRESP(len(list)))
 }
 
+func handleLpush(conn net.Conn, args []string) {
+	key := args[1]
+	newItems := args[2:]
+
+	if len(args) < 3 {
+        err := errors.New("wrong number of arguments for 'LPUSH'")
+        conn.Write(serializeRESP(err))
+		return
+    }
+
+	db.mu.Lock()
+	defer db.mu.Unlock()
+
+	var list []string
+	existingItem, exists := db.data[key]
+
+	if exists {
+		var ok bool
+		list, ok = existingItem.Value.([]string)
+		if !ok {
+			err := errors.New("WRONGTYPE Operation against a key holding the wrong kind of value")
+			conn.Write(serializeRESP(err))
+			return
+		}
+		} else {
+			list = []string{}
+		}
+	list = append(newItems, list...)
+	db.data[key] = Item{Value: list}
+	conn.Write(serializeRESP(len(list)))
+}
+
 func handleLrange(conn net.Conn, args []string) {
     db.mu.Lock()
     defer db.mu.Unlock()
diff --git a/main.go b/main.go
index cbdae4b..82c3542 100644
--- a/main.go
+++ b/main.go
@@ -25,6 +25,7 @@ var commandRegistry = map[string]handlerFunc{
     "PING":     handlePing,
     "FLUSHALL": handleFlushall,
     "RPUSH":    handleRpush,
+	"LPUSH":	handleLpush,
     "LRANGE":   handleLrange,
     "LPOP":     handleLpop,
     "RPOP":     handleRpop,