added test for RENAME command

internal/modules/generic/commands_test.go

@@ -2393,4 +2393,97 @@ func Test_Generic(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("Test_HandlerRENAME", func(t *testing.T) {
+		t.Parallel()
+		conn, err := internal.GetConnection("localhost", port)
+		if err != nil {
+			t.Error(err)
+			return
+		}
+		defer func() {
+			_ = conn.Close()
+		}()
+		client := resp.NewConn(conn)
+
+		tests := []struct {
+			name             string
+			oldKey           string
+			newKey           string
+			presetValue      interface{}
+			command          []resp.Value
+			expectedResponse string
+			expectedError    error
+		}{
+			{
+				name:             "1. Rename existing key",
+				oldKey:           "oldKey1",
+				newKey:           "newKey1",
+				presetValue:      "value1",
+				command:          []resp.Value{resp.StringValue("RENAME"), resp.StringValue("oldKey1"), resp.StringValue("newKey1")},
+				expectedResponse: "OK",
+				expectedError:    nil,
+			},
+			{
+				name:             "2. Rename non-existent key",
+				oldKey:           "oldKey2",
+				newKey:           "newKey2",
+				presetValue:      nil,
+				command:          []resp.Value{resp.StringValue("RENAME"), resp.StringValue("oldKey2"), resp.StringValue("newKey2")},
+				expectedResponse: "",
+				expectedError:    errors.New("no such key"),
+			},
+			{
+				name:             "3. Rename to existing key",
+				oldKey:           "oldKey3",
+				newKey:           "newKey3",
+				presetValue:      "value3",
+				command:          []resp.Value{resp.StringValue("RENAME"), resp.StringValue("oldKey3"), resp.StringValue("newKey3")},
+				expectedResponse: "OK",
+				expectedError:    nil,
+			},
+		}
+
+		for _, test := range tests {
+			t.Run(test.name, func(t *testing.T) {
+				if test.presetValue != nil {
+					command := []resp.Value{resp.StringValue("SET"), resp.StringValue(test.oldKey), resp.StringValue(fmt.Sprintf("%v", test.presetValue))}
+					if err = client.WriteArray(command); err != nil {
+						t.Error(err)
+					}
+					res, _, err := client.ReadValue()
+					if err != nil {
+						t.Error(err)
+					}
+					if !strings.EqualFold(res.String(), "OK") {
+						t.Errorf("expected preset response to be OK, got %s", res.String())
+					}
+				}
+
+				if err = client.WriteArray(test.command); err != nil {
+					t.Error(err)
+				}
+
+				res, _, err := client.ReadValue()
+				if err != nil {
+					t.Error(err)
+				}
+
+				if test.expectedError != nil {
+					if !strings.Contains(res.Error().Error(), test.expectedError.Error()) {
+						t.Errorf("expected error \"%s\", got \"%s\"", test.expectedError.Error(), res.Error().Error())
+					}
+					return
+				}
+
+				if err != nil {
+					t.Error(err)
+				} else {
+					if res.String() != test.expectedResponse {
+						t.Errorf("expected response \"%s\", got \"%s\"", test.expectedResponse, res.String())
+					}
+				}
+			})
+		}
+	})
 }