Go: Implement Server Management Command DBSize (valkey-io#2991)

* Implement DBSize Command

Signed-off-by: EdricCua <[email protected]>

Author: EdricCua

go/api/glide_client.go

@@ -67,3 +67,26 @@ func (client *glideClient) Select(index int64) (string, error) {
 
 	return handleStringResponse(result)
 }
+
+// Returns the number of keys in the currently selected database.
+//
+// Return value:
+//
+//	The number of keys in the currently selected database.
+//
+// Example:
+//
+//	result, err := client.DBSize()
+//	if err != nil {
+//		// handle error
+//	}
+//	fmt.Println(result) // Output: 1
+//
+// [valkey.io]: https://valkey.io/commands/dbsize/
+func (client *glideClient) DBSize() (int64, error) {
+	result, err := client.executeCommand(C.DBSize, []string{})
+	if err != nil {
+		return defaultIntResponse, err
+	}
+	return handleIntResponse(result)
+}

go/api/server_management_commands.go

@@ -61,4 +61,6 @@ type ServerManagementCommands interface {
 	//
 	// [valkey.io]: https://valkey.io/commands/config-set/
 	ConfigSet(parameters map[string]string) (string, error)
+
+	DBSize() (int64, error)
 }

go/integTest/standalone_commands_test.go

@@ -384,3 +384,10 @@ func (suite *GlideTestSuite) TestSortReadOnlyWithOptions_SuccessfulSortByWeightA
 	assert.Equal(suite.T(), "item1", sortResult[3].Value())
 	assert.Equal(suite.T(), "item3", sortResult[5].Value())
 }
+
+func (suite *GlideTestSuite) TestDBSize() {
+	client := suite.defaultClient()
+	result, err := client.DBSize()
+	assert.Nil(suite.T(), err)
+	assert.Greater(suite.T(), result, int64(0))
+}