Need Test class for following Rest Service class to insert update delete Lead record.
Can anyone help? please provide positive negative bulk test scenarios.






global class LeadManipulationSOAPService {

    /**
        This Wrapper class is created for returning the Response in this format.
     */
    global class ManipulationResponse {
        webservice Boolean isSuccess;
        webservice String lead;
        webservice String status;
    }


  /**
        This Method creates Lead using SOAP Webservice.
        @return ManipulationResponse - Response for external system.
     */
  webservice static ManipulationResponse createLead(
    String firstName, 
        String lastName, 
        String company,
        String email, 
        String phone
  ){
    Lead leadRecord = new Lead();
        ManipulationResponse returnResponse = new ManipulationResponse();
        returnResponse.isSuccess = false;
        returnResponse.lead = '';
            
        if( lastName == null || lastName.equals('') ) {
            returnResponse.status = 'Lead : Last Name is missing.';
            return returnResponse;
        } else if( company == null || company.equals('') ) {
            returnResponse.status = 'Lead : Company is missing.';
            return returnResponse;
        }

        leadRecord.FirstName = firstName;
        leadRecord.LastName = lastName;
        leadRecord.Email = email;
        leadRecord.Phone = phone;
        leadRecord.Company = company;

        try {
            insert leadRecord;
        } catch (DMLException ex) {
            returnResponse.status = 'Lead: Insertion Exception';
            return returnResponse;
        }

        returnResponse.isSuccess = true;
        returnResponse.lead = leadRecord.id;
        returnResponse.status = 'Success';

        return returnResponse;
  }


  /**
        This Method updates Lead using SOAP Webservice.
        @return ManipulationResponse - Response for external system.
     */
    webservice static ManipulationResponse updateLead(
        String firstName,
        String lastName,
        String newEmail,
        String newPhone
    ) {
        ManipulationResponse returnResponse = new ManipulationResponse();
        returnResponse.isSuccess = false;
        returnResponse.lead = '';
        List<Lead> leadList;
       
        leadList = [
            SELECT
                id,
                Email,
                Phone
            FROM
                Lead
            WHERE
                FirstName = :firstName 
            AND
                LastName = :lastName
        ];
        

    if(leadList.size() == 0) {
            returnResponse.status = 'Lead Update : No Lead found for Input Parameters.';
            return returnResponse;
        }

        for( Lead leadRecord : leadList ) {
            leadRecord.Email = newEmail;
            leadRecord.Phone = newPhone;
        }

        try {
            update leadList;
        } catch(DMLException ex) {
            returnResponse.status = 'Lead Updation : Failed';
            return returnResponse;
        }

        returnResponse.isSuccess = true;
        returnResponse.lead = leadList[0].id;
        returnResponse.status = 'Success';
        return returnResponse;
    }




  /**
        This Method deletes Lead using SOAP Webservice.
        @return ManipulationResponse - Response for external system.
     */
    webservice static ManipulationResponse deleteLead(
    String firstName,
        String lastName,
        String email,
        String phone
  ) {
        List<Lead> leadList;
        ManipulationResponse returnResponse = new ManipulationResponse();
        returnResponse.isSuccess = false;
        returnResponse.lead = '';

        leadList = [
            SELECT
                id
            FROM
                Lead
            WHERE
                FirstName = :firstName 
            AND
                LastName = :lastName
            AND 
                Email = :email
            AND
                Phone = :phone
        ];
        
        
        if(leadList.size() == 0) {
            returnResponse.status = 'Lead Deletion : No Lead found for Input Parameters.';
            return returnResponse;
        }

        try {
            delete leadList;
        } catch(DMLException ex) {
            returnResponse.status = 'Lead Deletion : Failed';
            return returnResponse;
        }

        returnResponse.isSuccess = true;
        returnResponse.lead = firstName + ' ' + lastName ;
        returnResponse.status = 'Success';
        return returnResponse;
    }

}