feat: INCR command added

echovault/api_generic.go

@@ -15,9 +15,10 @@
 package echovault
 
 import (
-	"github.com/echovault/echovault/internal"
 	"strconv"
 	"strings"
+
+	"github.com/echovault/echovault/internal"
 )
 
 // SetOptions modifies the behaviour for the Set command
@@ -416,3 +417,17 @@ func (server *EchoVault) PExpireAt(key string, unixMilliseconds int, options PEx
 
 	return internal.ParseIntegerResponse(b)
 }
+
+func (server *EchoVault) Incr(key string) (int, error) {
+    // Construct the command
+    cmd := []string{"INCR", key}
+
+    // Execute the command
+    b, err := server.handleCommand(server.context, internal.EncodeCommand(cmd), nil, false, true)
+    if err != nil {
+        return 0, err
+    }
+
+    // Parse the integer response
+    return internal.ParseIntegerResponse(b)
+}

echovault/api_generic_test.go

@@ -16,13 +16,14 @@ package echovault
 
 import (
 	"context"
-	"github.com/echovault/echovault/internal"
-	"github.com/echovault/echovault/internal/clock"
 	"reflect"
 	"slices"
 	"strings"
 	"testing"
 	"time"
+
+	"github.com/echovault/echovault/internal"
+	"github.com/echovault/echovault/internal/clock"
 )
 
 func TestEchoVault_DEL(t *testing.T) {

internal/modules/generic/commands.go

@@ -17,12 +17,13 @@ package generic
 import (
 	"errors"
 	"fmt"
-	"github.com/echovault/echovault/internal"
-	"github.com/echovault/echovault/internal/constants"
 	"log"
 	"strconv"
 	"strings"
 	"time"
+
+	"github.com/echovault/echovault/internal"
+	"github.com/echovault/echovault/internal/constants"
 )
 
 type KeyObject struct {
@@ -382,6 +383,50 @@ func handleExpireAt(params internal.HandlerFuncParams) ([]byte, error) {
 	return []byte(":1\r\n"), nil
 }
 
+func handleIncr(params internal.HandlerFuncParams) ([]byte, error) {
+	// Extract key from command
+	keys, err := incrKeyFunc(params.Command)
+	if err != nil {
+		return nil, err
+	}
+
+	key := keys.WriteKeys[0]
+	currentValue, ok := params.GetValues(params.Context, []string{key})[key]
+
+	var newValue int64
+	var currentValueInt int64
+
+	// Check if the key exists and its current value
+	if !ok {
+		// If key does not exist, initialize it with 1
+		newValue = 1
+	} else {
+		// Use type switch to handle different types of currentValue
+		switch v := currentValue.(type) {
+		case string:
+			var err error
+			currentValueInt, err = strconv.ParseInt(v, 10, 64)
+			if err != nil {
+				return nil, errors.New("value is not an integer or out of range")
+			}
+		case int:
+			currentValueInt = int64(v)
+		case int64:
+			currentValueInt = v
+		default:
+			return nil, errors.New("unexpected type for currentValue")
+		}
+		newValue = currentValueInt + 1
+	}
+
+	// Set the new incremented value
+	if err := params.SetValues(params.Context, map[string]interface{}{key: fmt.Sprintf("%d", newValue)}); err != nil {
+		return nil, err
+	}
+
+	// Prepare response with the actual new value
+	return []byte(fmt.Sprintf(":%d\r\n", newValue)), nil
+}
 func Commands() []internal.Command {
 	return []internal.Command{
 		{
@@ -550,5 +595,14 @@ LT - Only set the expiry time if the new expiry time is less than the current on
 			KeyExtractionFunc: expireAtKeyFunc,
 			HandlerFunc:       handleExpireAt,
 		},
+		{
+			Command:           "incr",
+			Module:            constants.GenericModule,
+			Categories:        []string{constants.KeyspaceCategory, constants.WriteCategory, constants.FastCategory},
+			Description:       `(INCR key) Increments the number stored at key by one. 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 cannot be represented as integer. This operation is limited to 64 bit signed integers.`,
+			Sync:              true,
+			KeyExtractionFunc: incrKeyFunc,
+			HandlerFunc:       handleIncr,
+		},
 	}
 }

internal/modules/generic/commands_test.go

@@ -17,15 +17,16 @@ package generic_test
 import (
 	"errors"
 	"fmt"
+	"strings"
+	"testing"
+	"time"
+
 	"github.com/echovault/echovault/echovault"
 	"github.com/echovault/echovault/internal"
 	"github.com/echovault/echovault/internal/clock"
 	"github.com/echovault/echovault/internal/config"
 	"github.com/echovault/echovault/internal/constants"
 	"github.com/tidwall/resp"
-	"strings"
-	"testing"
-	"time"
 )
 
 type KeyData struct {
@@ -1893,5 +1894,4 @@ func Test_Generic(t *testing.T) {
 			})
 		}
 	})
-
 }

internal/modules/generic/key_funcs.go

@@ -16,6 +16,7 @@ package generic
 
 import (
 	"errors"
+
 	"github.com/echovault/echovault/internal"
 	"github.com/echovault/echovault/internal/constants"
 )
@@ -135,3 +136,12 @@ func expireAtKeyFunc(cmd []string) (internal.KeyExtractionFuncResult, error) {
 		WriteKeys: cmd[1:2],
 	}, nil
 }
+
+func incrKeyFunc(cmd []string) (internal.KeyExtractionFuncResult, error) {
+	if len(cmd) != 2 {
+		return internal.KeyExtractionFuncResult{}, errors.New("wrong number of arguments for INCR")
+	}
+	return internal.KeyExtractionFuncResult{
+		WriteKeys: cmd[1:2],
+	}, nil
+}