Merge pull request #73 from dotslashbit/issue-55

feat: added ECHO command

internal/modules/connection/commands.go

@@ -17,6 +17,7 @@ package connection
 import (
 	"errors"
 	"fmt"
+
 	"github.com/echovault/echovault/internal"
 	"github.com/echovault/echovault/internal/constants"
 )
@@ -32,13 +33,20 @@ func handlePing(params internal.HandlerFuncParams) ([]byte, error) {
 	}
 }
 
+func handleEcho(params internal.HandlerFuncParams) ([]byte, error) {
+	if len(params.Command) != 2 {
+		return nil, errors.New(constants.WrongArgsResponse)
+	}
+	return []byte(fmt.Sprintf("$%d\r\n%s\r\n", len(params.Command[1]), params.Command[1])), nil
+}
+
 func Commands() []internal.Command {
 	return []internal.Command{
 		{
 			Command:    "ping",
 			Module:     constants.ConnectionModule,
 			Categories: []string{constants.ConnectionCategory, constants.FastCategory},
-			Description: `(PING [message]) 
+			Description: `(PING [message])
 Ping the echovault server. If a message is provided, the message will be echoed back to the client.
 Otherwise, the server will return "PONG".`,
 			Sync: false,
@@ -51,5 +59,21 @@ Otherwise, the server will return "PONG".`,
 			},
 			HandlerFunc: handlePing,
 		},
+		{
+			Command:    "echo",
+			Module:     constants.ConnectionModule,
+			Categories: []string{constants.ConnectionCategory, constants.FastCategory},
+			Description: `(ECHO message)
+Echo the message back to the client.`,
+			Sync: false,
+			KeyExtractionFunc: func(cmd []string) (internal.KeyExtractionFuncResult, error) {
+				return internal.KeyExtractionFuncResult{
+					Channels:  make([]string, 0),
+					ReadKeys:  make([]string, 0),
+					WriteKeys: make([]string, 0),
+				}, nil
+			},
+			HandlerFunc: handleEcho,
+		},
 	}
 }

internal/modules/connection/commands_test.go

@@ -16,13 +16,14 @@ package connection_test
 
 import (
 	"errors"
+	"strings"
+	"testing"
+
 	"github.com/echovault/echovault/echovault"
 	"github.com/echovault/echovault/internal"
 	"github.com/echovault/echovault/internal/config"
 	"github.com/echovault/echovault/internal/constants"
 	"github.com/tidwall/resp"
-	"strings"
-	"testing"
 )
 
 func Test_Connection(t *testing.T) {
@@ -114,4 +115,66 @@ func Test_Connection(t *testing.T) {
 		}
 	})
 
+
+	t.Run("Test_HandleEcho", func(t *testing.T) {
+			conn, err := internal.GetConnection("localhost", port)
+			if err != nil {
+				t.Error(err)
+				return
+			}
+			defer func() {
+				_ = conn.Close()
+			}()
+			client := resp.NewConn(conn)
+
+			tests := []struct {
+				command     []resp.Value
+				expected    string
+				expectedErr error
+			}{
+				{
+					command:     []resp.Value{resp.StringValue("ECHO"), resp.StringValue("Hello, EchoVault!")},
+					expected:    "Hello, EchoVault!",
+					expectedErr: nil,
+				},
+				{
+					command:     []resp.Value{resp.StringValue("ECHO")},
+					expected:    "",
+					expectedErr: errors.New(constants.WrongArgsResponse),
+				},
+				{
+					command: []resp.Value{
+						resp.StringValue("ECHO"),
+						resp.StringValue("Hello, EchoVault!"),
+						resp.StringValue("Once more"),
+					},
+					expected:    "",
+					expectedErr: errors.New(constants.WrongArgsResponse),
+				},
+			}
+
+			for _, test := range tests {
+				if err = client.WriteArray(test.command); err != nil {
+					t.Error(err)
+					return
+				}
+
+				res, _, err := client.ReadValue()
+				if err != nil {
+					t.Error(err)
+				}
+
+				if test.expectedErr != nil {
+					if !strings.Contains(res.Error().Error(), test.expectedErr.Error()) {
+						t.Errorf("expected error \"%s\", got \"%s\"", test.expectedErr.Error(), res.Error().Error())
+					}
+					continue
+				}
+
+				if res.String() != test.expected {
+					t.Errorf("expected response \"%s\", got \"%s\"", test.expected, res.String())
+				}
+			}
+		})
+
 }