Merge pull request #81 from dotslashbit/issue-58

feat: Added RENAME command

echovault/api_generic.go

@@ -507,3 +507,25 @@ func (server *EchoVault) DecrBy(key string, value string) (int, error) {
 	// Parse the integer response
 	return internal.ParseIntegerResponse(b)
 }
+
+// Rename renames the key from oldKey to newKey.
+// If the oldKey does not exist, an error is returned.
+//
+// Parameters:
+//
+// `oldKey` - string - The key to be renamed.
+//
+// `newKey` - string - The new name for the key.
+//
+// Returns: A string indicating the success of the operation.
+func (server *EchoVault) Rename(oldKey string, newKey string) (string, error) {
+	// Construct the command
+	cmd := []string{"RENAME", oldKey, newKey}
+	// Execute the command
+	b, err := server.handleCommand(server.context, internal.EncodeCommand(cmd), nil, false, true)
+	if err != nil {
+		return "", err
+	}
+	// Parse the simple string response
+	return internal.ParseStringResponse(b)
+}

echovault/api_generic_test.go

@@ -1184,3 +1184,58 @@ func TestEchoVault_DECRBY(t *testing.T) {
 		})
 	}
 }
+
+func TestEchoVault_Rename(t *testing.T) {
+	server := createEchoVault()
+
+	tests := []struct {
+		name         string
+		oldKey       string
+		newKey       string
+		presetValues map[string]internal.KeyData
+		want         string
+		wantErr      bool
+	}{
+		{
+			name:         "1. Rename existing key",
+			oldKey:       "oldKey1",
+			newKey:       "newKey1",
+			presetValues: map[string]internal.KeyData{"oldKey1": {Value: "value1"}},
+			want:         "OK",
+			wantErr:      false,
+		},
+		{
+			name:         "2. Rename non-existent key",
+			oldKey:       "oldKey2",
+			newKey:       "newKey2",
+			presetValues: nil,
+			want:         "",
+			wantErr:      true,
+		},
+		{
+			name:         "3. Rename to existing key",
+			oldKey:       "oldKey3",
+			newKey:       "newKey4",
+			presetValues: map[string]internal.KeyData{"oldKey3": {Value: "value3"}, "newKey4": {Value: "value4"}},
+			want:         "OK",
+			wantErr:      false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if tt.presetValues != nil {
+				for k, d := range tt.presetValues {
+					presetKeyData(server, context.Background(), k, d)
+				}
+			}
+			got, err := server.Rename(tt.oldKey, tt.newKey)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("Rename() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if got != tt.want {
+				t.Errorf("Rename() got = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

internal/modules/generic/commands.go

@@ -581,6 +581,35 @@ func handleDecrBy(params internal.HandlerFuncParams) ([]byte, error) {
 	return []byte(fmt.Sprintf(":%d\r\n", newValue)), nil
 }
 
+func handleRename(params internal.HandlerFuncParams) ([]byte, error) {
+	if len(params.Command) != 3 {
+		return nil, errors.New(constants.WrongArgsResponse)
+	}
+
+	oldKey := params.Command[1]
+	newKey := params.Command[2]
+
+	// Get the current value for the old key
+	values := params.GetValues(params.Context, []string{oldKey})
+	oldValue, ok := values[oldKey]
+
+	if !ok || oldValue == nil {
+		return nil, errors.New("no such key")
+	}
+
+	// Set the new key with the old value
+	if err := params.SetValues(params.Context, map[string]interface{}{newKey: oldValue}); err != nil {
+		return nil, err
+	}
+
+	// Delete the old key
+	if err := params.DeleteKey(oldKey); err != nil {
+		return nil, err
+	}
+
+	return []byte("+OK\r\n"), nil
+}
+
 func Commands() []internal.Command {
 	return []internal.Command{
 		{
@@ -778,8 +807,8 @@ This operation is limited to 64 bit signed integers.`,
 			Command:    "incrby",
 			Module:     constants.GenericModule,
 			Categories: []string{constants.KeyspaceCategory, constants.WriteCategory, constants.FastCategory},
-			Description: `(INCRBY key increment) 
-Increments the number stored at key by increment. If the key does not exist, it is set to 0 before performing the operation. 
+			Description: `(INCRBY key increment)
+Increments the number stored at key by increment. If the key does not exist, it is set to 0 before performing the operation.
 An error is returned if the key contains a value of the wrong type or contains a string that can not be represented as integer.`,
 			Sync:              true,
 			KeyExtractionFunc: incrByKeyFunc,
@@ -789,13 +818,23 @@ An error is returned if the key contains a value of the wrong type or contains a
 			Command:    "decrby",
 			Module:     constants.GenericModule,
 			Categories: []string{constants.KeyspaceCategory, constants.WriteCategory, constants.FastCategory},
-			Description: `(DECRBY key decrement) 
-The DECRBY command reduces the value stored at the specified key by the specified decrement. 
-If the key does not exist, it is initialized with a value of 0 before performing the operation. 
+			Description: `(DECRBY key decrement)
+The DECRBY command reduces the value stored at the specified key by the specified decrement.
+If the key does not exist, it is initialized with a value of 0 before performing the operation.
 If the key's value is not of the correct type or cannot be represented as an integer, an error is returned.`,
 			Sync:              true,
 			KeyExtractionFunc: decrByKeyFunc,
 			HandlerFunc:       handleDecrBy,
 		},
+		{
+			Command:    "rename",
+			Module:     constants.GenericModule,
+			Categories: []string{constants.KeyspaceCategory, constants.WriteCategory, constants.FastCategory},
+			Description: `(RENAME key newkey) 
+Renames key to newkey. If newkey already exists, it is overwritten. If key does not exist, an error is returned.`,
+			Sync:              true,
+			KeyExtractionFunc: renameKeyFunc,
+			HandlerFunc:       handleRename,
+		},
 	}
 }

internal/modules/generic/commands_test.go

@@ -2393,4 +2393,112 @@ 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,
+			},
+			{
+				name:          "4. Command too short",
+				command:       []resp.Value{resp.StringValue("RENAME"), resp.StringValue("key")},
+				expectedError: errors.New(constants.WrongArgsResponse),
+			},
+			{
+				name: "5. Command too long",
+				command: []resp.Value{
+					resp.StringValue("RENAME"),
+					resp.StringValue("key"),
+					resp.StringValue("newkey"),
+					resp.StringValue("extra_arg"),
+				},
+				expectedError: errors.New(constants.WrongArgsResponse),
+			},
+		}
+
+		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())
+					}
+				}
+			})
+		}
+	})
 }

internal/modules/generic/key_funcs.go

@@ -172,3 +172,12 @@ func decrByKeyFunc(cmd []string) (internal.KeyExtractionFuncResult, error) {
 		WriteKeys: []string{cmd[1]},
 	}, nil
 }
+
+func renameKeyFunc(cmd []string) (internal.KeyExtractionFuncResult, error) {
+	if len(cmd) != 3 {
+		return internal.KeyExtractionFuncResult{}, errors.New(constants.WrongArgsResponse)
+	}
+	return internal.KeyExtractionFuncResult{
+		WriteKeys: cmd[1:3],
+	}, nil
+}