fix(approvers): duplicated approver is not allowed (#135)

* fix(approvers): duplicated approver is not allowed

* test: adding unit test

* chore: update error log

Co-authored-by: Rahmat Hidayat <[email protected]>

---------

Co-authored-by: Muhammad Idil Haq Amir <[email protected]>
Co-authored-by: Rahmat Hidayat <[email protected]>

Makefile

@@ -80,3 +80,4 @@ setup:
 	go get github.com/grpc-ecosystem/grpc-gateway/v2/[email protected]
 	go get github.com/bufbuild/buf/cmd/[email protected]
 	go get github.com/vektra/mockery/[email protected]
+

core/appeal/service.go

@@ -681,6 +681,11 @@ func (s *Service) AddApprover(ctx context.Context, appealID, approvalID, email s
 	if appeal.Status != domain.AppealStatusPending {
 		return nil, fmt.Errorf("%w: can't add new approver to appeal with %q status", ErrUnableToAddApprover, appeal.Status)
 	}
+	for _, existingApprover := range approval.Approvers {
+		if email == existingApprover {
+			return nil, fmt.Errorf("%w: approver %q already exists", ErrUnableToAddApprover, email)
+		}
+	}
 
 	switch approval.Status {
 	case domain.ApprovalStatusPending:

core/appeal/service_test.go

@@ -3177,6 +3177,30 @@ func (s *ServiceTestSuite) TestAddApprover() {
 		s.ErrorIs(err, expectedError)
 		s.mockRepository.AssertExpectations(s.T())
 	})
+
+	s.Run("should return error if the new approver is already exist on the current approval", func() {
+		expectedError := appeal.ErrUnableToAddApprover
+		approvalID := uuid.New().String()
+		expectedAppeal := &domain.Appeal{
+			Status: domain.AppealStatusPending,
+			Approvals: []*domain.Approval{
+				{
+					ID:        approvalID,
+					Status:    domain.ApprovalStatusPending,
+					Approvers: []string{"[email protected]"},
+				},
+			},
+		}
+		s.mockRepository.EXPECT().
+			GetByID(mock.MatchedBy(func(ctx context.Context) bool { return true }), mock.Anything).
+			Return(expectedAppeal, nil).Once()
+
+		appeal, err := s.service.AddApprover(context.Background(), uuid.New().String(), approvalID, "[email protected]")
+
+		s.Nil(appeal)
+		s.ErrorIs(err, expectedError)
+		s.mockRepository.AssertExpectations(s.T())
+	})
 }
 
 func (s *ServiceTestSuite) TestDeleteApprover() {