I have working Code the sends an SMS or Voice call via Apex and Twilio, Great stuff. The trouble I am having is writing the Tests (maybe because its Friday?) and I just need a little help. I don't do near enough Apex for my liking and I am feeling it here. 

I know I should be writing a Http mock someplace in my test...Any help/pointers would be most appreciated. 

Working SMS:

public class TwilioSMSInvocable {
        @InvocableMethod
        public static void callPhoneService(List<ID> caseIDs) {
            List<Twilio_SMS__c> SelectTwilio_SMS = [Select Id, MobileNumber__C, Message__c from Twilio_SMS__c Where ID in :caseIDs] ;
        for (Twilio_SMS__c t : SelectTwilio_SMS){
               Map<String,String> params = new Map<String,String> {
                 'To'   => t.MobileNumber__c,
                 'From' => '13176666666',                
                 'Body' => t.Message__c
             };
              
                DoCallout(params);      
         }
            }
        
        @future(callout=true)
        
        private static void DoCallout(Map<String, String> params){
            String account = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';
            String token = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';
            TwilioRestClient client = new TwilioRestClient(account, token);
            TwilioSMS sms = client.getAccount().getSMSMessages().create(params);
             System.Debug('TwilioSMS ' + sms) ;
        }
    }

   
Working Voice:

   

public class TwilioCallInvocable {
    
        @InvocableMethod
        public static void callPhoneService(List<ID> caseIDs) {
            List<Twilio_Voice__c> SelectTwilio_Voice = [Select Id, Say__c, URL_Build__c from Twilio_Voice__c Where ID in :caseIDs] ;
        for (Twilio_Voice__c t : SelectTwilio_Voice){
               Map<String,String> params = new Map<String,String> {
            'To'   => t.MobileNumber__c,
            'From' => '+13176666666',               
                'Url' => t.URL_Build__c
            };
              
                DoCallout(params);      
           }
        }
        
        @future(callout=true)
        
        private static void DoCallout(Map<String, String> params){
            String account = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';
            String token = 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx';
            TwilioRestClient client = new TwilioRestClient(account, token);
            TwilioCall call = client.getAccount().getCalls().create(params);
                system.debug('TwilioCAL' + call);
        }
    }

Test Class:

   

@isTest
    private class TwilioSMSTest 
    {
        static testmethod void testTwilioSMSInvocable() 
        {
            Map<String,String> params = new Map<String,String> {
                 'To'   => '+17602444355',
                 'From' => '13176664444',               
                 'Body' => 'test message'
             };
                String account = 'AC6a217d8adb3460b5870c05bc6c666666';
            String token = '397c3f614cd3cf783154dc2383234444';
            TwilioRestClient client = new TwilioRestClient(account, token);
            TwilioSMS sms = client.getAccount().getSMSMessages().create(params);
            test.startTest();
                 Test.setMock(HttpCalloutMock.class, new TwilioSMSTest());
            test.stopTest();
        }
    }

I am getting 0 error messages, and 0 test coverage