diff --git a/config/rjreader_test.go b/config/rjreader_test.go
index b21705c4f..729de2004 100644
--- a/config/rjreader_test.go
+++ b/config/rjreader_test.go
@@ -18,6 +18,11 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 package config
 
 import (
+	"bufio"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
 	"os"
 	"reflect"
 	"testing"
@@ -350,3 +355,229 @@ func TestGetErrorLine2(t *testing.T) {
 	}
 
 }
+
+type reader struct {
+}
+
+func (r *reader) Read(p []byte) (n int, err error) {
+	return 0, fmt.Errorf("test error: %v", n)
+}
+
+func TestRjReaderNewRjReader(t *testing.T) {
+	r := &reader{}
+
+	rcv, err := NewRjReader(r)
+
+	if err != nil {
+		if err.Error() != "test error: 0" {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+
+	if rcv != nil {
+		t.Error(rcv)
+	}
+}
+
+func TestRjReaderUnreadByte(t *testing.T) {
+	val := "val1"
+	mrsh, err := json.Marshal(val)
+	if err != nil {
+		t.Error(err)
+	}
+	rjr := &rjReader{
+		buf:        mrsh,
+		isInString: true,
+		indx:       0,
+	}
+
+	err = rjr.UnreadByte()
+
+	if err != nil {
+		if err.Error() != bufio.ErrInvalidUnreadByte.Error() {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+}
+
+func TestRjReaderconsumeComent(t *testing.T) {
+	val := "1"
+	mrsh, err := json.Marshal(val)
+	if err != nil {
+		t.Error(err)
+	}
+	rjr := &rjReader{
+		buf:        mrsh,
+		isInString: true,
+		indx:       20,
+	}
+
+	rcv, err := rjr.consumeComent('*')
+
+	if err != nil {
+		if err.Error() != utils.ErrJsonIncompleteComment.Error() {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+
+	if rcv != true {
+		t.Error(rcv)
+	}
+}
+
+func TestRjReaderPeekByteWC(t *testing.T) {
+	val := "1"
+	mrsh, err := json.Marshal(val)
+	if err != nil {
+		t.Error(err)
+	}
+	rjr := &rjReader{
+		buf:        mrsh,
+		isInString: true,
+		indx:       20,
+	}
+
+	rcv, err := rjr.PeekByteWC()
+
+	if err != nil {
+		if err.Error() != io.EOF.Error() {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+
+	if rcv != 0 {
+		t.Error(rcv)
+	}
+}
+
+func TestRjReaderreadEnvName(t *testing.T) {
+	val := "val1"
+	mrsh, err := json.Marshal(val)
+	if err != nil {
+		t.Error(err)
+	}
+	rjr := &rjReader{
+		buf:        mrsh,
+		isInString: true,
+		indx:       0,
+	}
+
+	rcv1, rcv2, err := rjr.readEnvName(20)
+
+	if err != nil {
+		if err.Error() != io.EOF.Error() {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+
+	if rcv1 != nil {
+		t.Error(rcv1)
+	}
+
+	if rcv2 != 20 {
+		t.Error(rcv2)
+	}
+}
+
+func TestRjReaderReplaceEnv(t *testing.T) {
+	val := "val1"
+	mrsh, err := json.Marshal(val)
+	if err != nil {
+		t.Error(err)
+	}
+	rjr := &rjReader{
+		buf:        mrsh,
+		isInString: true,
+		indx:       0,
+	}
+
+	err = rjr.replaceEnv(20)
+
+	if err != nil {
+		if err.Error() != "NOT_FOUND:ENV_VAR:" {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+}
+
+func TestRjReaderHandleJSONError(t *testing.T) {
+	err1 := &json.InvalidUTF8Error{
+		S: "test err1",
+	}
+	err2 := &json.InvalidUnmarshalError{
+		Type: reflect.TypeOf(fmt.Errorf("error %s", "test")),
+	}
+	err3 := &json.UnmarshalTypeError{
+		Type: reflect.TypeOf(fmt.Errorf("error %s", "test")),
+	}
+	val := "val1"
+	mrsh, err := json.Marshal(val)
+	if err != nil {
+		t.Error(err)
+	}
+	rjr := &rjReader{
+		buf:        mrsh,
+		isInString: true,
+		indx:       0,
+	}
+
+	tests := []struct {
+		name string
+		arg  error
+		exp  string
+	}{
+		{
+			name: "case nil",
+			arg:  nil,
+			exp:  "",
+		},
+		{
+			name: "case *json.InvalidUTF8Error, *json.UnmarshalFieldError",
+			arg:  err1,
+			exp:  `json: invalid UTF-8 in string: "test err1"`,
+		},
+		{
+			name: "case *json.InvalidUnmarshalError",
+			arg:  err2,
+			exp:  `json: Unmarshal(nil *errors.errorString)`,
+		},
+		{
+			name: "case *json.UnmarshalTypeError",
+			arg:  err3,
+			exp:  `json: cannot unmarshal  into Go value of type *errors.errorString at line 0 around position 0`,
+		},
+		{
+			name: "case default",
+			arg:  errors.New("test error"),
+			exp:  `test error`,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := rjr.HandleJSONError(tt.arg)
+
+			if tt.exp != "" {
+				if err != nil {
+					if err.Error() != tt.exp {
+						t.Error(err)
+					}
+				} else {
+					t.Error("was expecting an error")
+				}
+			}
+		})
+	}
+}
diff --git a/engine/cgrsafev_test.go b/engine/cgrsafev_test.go
new file mode 100644
index 000000000..de288bd89
--- /dev/null
+++ b/engine/cgrsafev_test.go
@@ -0,0 +1,55 @@
+/*
+Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
+Copyright (C) ITsysCOM GmbH
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>
+*/
+
+package engine
+
+import (
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/cgrates/cgrates/utils"
+)
+
+func TestCGRSafEventNewCGRSafEventFromCGREventAsCGREvent(t *testing.T) {
+	tm := time.Date(2021, 8, 15, 14, 30, 45, 100, time.Local)
+	cgrEv := &utils.CGREvent{
+		Tenant: "test",
+		ID:     "test",
+		Time:   &tm,
+		Event:  map[string]any{"test": 1},
+	}
+
+	exp := &CGRSafEvent{
+		Tenant: cgrEv.Tenant,
+		ID:     cgrEv.ID,
+		Time:   cgrEv.Time,
+		Event:  NewSafEvent(cgrEv.Event),
+	}
+	rcv := NewCGRSafEventFromCGREvent(cgrEv)
+
+	if !reflect.DeepEqual(exp, rcv) {
+		t.Errorf("\nexpected: %s\nreceived: %s\n", utils.ToJSON(exp), utils.ToJSON(rcv))
+	}
+
+	rcv2 := rcv.AsCGREvent()
+
+	if !reflect.DeepEqual(cgrEv, rcv2) {
+		t.Errorf("\nexpected: %s\nreceived: %s\n", utils.ToJSON(cgrEv), utils.ToJSON(rcv2))
+	}
+}
diff --git a/engine/chargers_test.go b/engine/chargers_test.go
index 4909c2d48..a1836980f 100644
--- a/engine/chargers_test.go
+++ b/engine/chargers_test.go
@@ -356,6 +356,21 @@ func TestChargerV1ProcessEvent(t *testing.T) {
 
 }
 
+func TestChargersV1ProcessEvent(t *testing.T) {
+	cS := &ChargerService{}
+	args := &utils.CGREventWithArgDispatcher{}
+
+	err := cS.V1ProcessEvent(args, nil)
+
+	if err != nil {
+		if err.Error() != utils.NewErrMandatoryIeMissing("Event").Error() {
+			t.Error(err)
+		}
+	} else {
+		t.Error("was expecting an error")
+	}
+}
+
 // func TestChSListenAndServe(t *testing.T) {
 // 	cfg, _ := config.NewDefaultCGRConfig()
 // 	db := NewInternalDB(nil, nil, true, cfg.DataDbCfg().Items)
diff --git a/engine/eventcost_test.go b/engine/eventcost_test.go
index 84bf45b94..c6a20f9bf 100644
--- a/engine/eventcost_test.go
+++ b/engine/eventcost_test.go
@@ -3679,3 +3679,80 @@ func TestEventCostnewChargingIncrement(t *testing.T) {
 		t.Errorf("expected %v, received %v", exp, rcv)
 	}
 }
+
+func TestEventCostAsRefundIncrements(t *testing.T) {
+	str := "test"
+	td := 1 * time.Second
+	ec := &EventCost{
+		CGRID:          str,
+		RunID:          str,
+		StartTime:      time.Date(2021, 8, 15, 14, 30, 45, 100, time.Local),
+		Usage:          &td,
+	}
+
+	rcv := ec.AsRefundIncrements(str)
+	exp := &CallDescriptor{
+		CgrID:         ec.CGRID,
+		RunID:         ec.RunID,
+		ToR:           str,
+		TimeStart:     ec.StartTime,
+		TimeEnd:       ec.StartTime.Add(ec.GetUsage()),
+		DurationIndex: ec.GetUsage(),
+	}
+
+	if !reflect.DeepEqual(exp, rcv) {
+		t.Errorf("\nexpected: %s\nreceived: %s\n", utils.ToJSON(exp), utils.ToJSON(rcv))
+	}
+}
+
+func TestEventCostappendChargingIntervalFromEventCost(t *testing.T) {
+	str := "test"
+	td := 1 * time.Second
+	fl := 1.2
+	str2 := "test2"
+	td2 := 2 * time.Millisecond
+	ec := &EventCost{
+		CGRID:          str,
+		RunID:          str,
+		StartTime:      time.Date(2021, 8, 15, 14, 30, 45, 100, time.Local),
+		Usage:          &td,
+		Charges:        []*ChargingInterval{{
+			RatingID:       str,             
+			Increments:     []*ChargingIncrement{{
+				Usage:          td,
+				Cost:           fl,
+				AccountingID:   str,
+				CompressFactor: 1,
+			}},
+			CompressFactor: 1,
+			usage:          &td,
+			ecUsageIdx:     &td,
+			cost:           &fl,
+		}, 
+	}}
+	oEC := &EventCost{
+		CGRID:          str2,
+		RunID:          str2,
+		StartTime:      time.Date(2022, 8, 15, 14, 30, 45, 100, time.Local),
+		Usage:          &td2,
+		Charges:        []*ChargingInterval{{
+			RatingID:       str,             
+			Increments:     []*ChargingIncrement{{
+				Usage:          td,
+				Cost:           fl,
+				AccountingID:   str,
+				CompressFactor: 1,
+			}},
+			CompressFactor: 1,
+			usage:          &td,
+			ecUsageIdx:     &td,
+			cost:           &fl,
+		}},
+	}
+
+	ec.appendChargingIntervalFromEventCost(oEC, 0)
+
+	if ec.Charges[0].CompressFactor != 2 {
+		t.Error("didn't append charging interval from event cost")
+	}
+}