@isTest
public class AppTriggerTest {

    @isTest static void updateSharingOppFilesTest() {
       
           //Create test NON Community user
           User regUsr = new User(LastName = 'LastName Reg',
                                  Alias = 'UsrR',
                                  Email = 'ClasstestReg@curious-fox.com',
                                  Username = 'ClasstestReg@test.com',
                                  CommunityNickname = 'ClassTestReg',
                                  ProfileId = [SELECT Id from Profile WHERE Name = 'Standard User' LIMIT 1].id,
                                  FirstName = 'Test Reg',
                                  TimeZoneSidKey = 'America/Los_Angeles', 
                                  LocaleSidKey = 'en_US',
                                  EmailEncodingKey = 'UTF-8', 
                                  LanguageLocaleKey = 'en_US'); 

             
          insert regUsr; //Temporarily commit user to the database
        
          //Create test community user
          User comUsr = new User(LastName = 'LastName Com',
                                  Alias = 'UsrC',
                                  Email = 'ClasstestCom@curious-fox.com',
                                  Username = 'ClasstestCom@test.com',
                                  CommunityNickname = 'ClassTestCom',
                                  ProfileId = [SELECT Id from Profile WHERE Name = 'Journey Assessor' LIMIT 1].id,
                                  //ProfileId = [SELECT ID from Profile WHERE Name = 'Standard Platform User'].id,
                                  FirstName = 'Test Com',
                                  TimeZoneSidKey = 'America/Los_Angeles', 
                                  LocaleSidKey = 'en_US',
                                  EmailEncodingKey = 'UTF-8', 
                                  LanguageLocaleKey = 'en_US');
        
        insert comUsr; //Temporarily commit user to database
        
        
        //Create test Opportunity records - REPLACE THIS WI
        List <Opportunity> testOpps = new List <Opportunity>();
        
        for (Integer i = 0; i < 200; i++) {
            
            //REPLACE THE CODE BELOW WITH THE FIELDS FROM YOUR APPLICATION OBJECT AND ASSIGN TEST VALUES
            testOpps.add(new Opportunity(Name = 'Test Opp #' + i,
                                         CloseDate = date.today().addDays(360),
                                         StageName = 'Prospecting',
                                         OwnerID = regUsr.id));
  
        }
        
        insert testOpps; //Temporarily commit test records to database
        
        //Create a map of old records - REQUIRED FOR TESTING!
        Map <ID, Opportunity> oldOppMap = new Map <ID, Opportunity>(testOpps);
        
        //Create list to hold test Files
        List <ContentVersion> testFile = new List <ContentVersion>();
        
        List <ContentDocumentLink> testFileLinks = new List <ContentDocumentLink>();

        for (Integer i = 0; i < 200; i++) {
                
               testFile.add(new ContentVersion(Title = 'Cats #' + i,
             				                   PathOnClient = 'Cats' + i +'.jpg',
                                               VersionData = Blob.valueOf('Test Content'),
                                               IsMajorVersion = true)); 

        }
        
        insert testFile; //Commit Temporary Files to Database
        
        List <ContentDocument> testFileDocs = [SELECT ID, Title FROM ContentDocument];
        
        System.assertEquals(200, testFileDocs.size()); //Checks to ensure that there are 200 records in the above list
        
        //Create test File Links - This controls file sharing - IMPORTANT!
        List <ContentDocumentLink> testFileLink = new List <ContentDocumentLink>();
        
        //Create test File Links
        for (Integer i = 0; i < 200; i++) {
            
            //Intentionally made Visibility = 'InternalUsers' since this untoggles Customer Access
            //If test is successful, visibility for these file links should change to 'AllUsers'
            testFileLink.add(new ContentDocumentLink(LinkedEntityID = testOpps[i].id,
                                                     ContentDocumentID = testFileDocs[i].id,
                                                     Visibility = 'InternalUsers',
                                                     ShareType = 'V'));
            
            
        }
        
        insert testFileLink; //Commit temporary file links to database
        
       
        //All necessary components configured. Perform record updates for testing
        
        //Create list to hold updated records
        List <Opportunity> updatedTestOpps = new List <Opportunity>();
        
        for (Opportunity oneTestOpp : testOpps) {
            
            oneTestOpp.OwnerID = comUsr.id;
            updatedTestOpps.add(oneTestOpp);  
            
        }
        
        //Initiate Testing
        System.Test.startTest();
        update updatedTestOpps; //This will provide test coverage for Apex trigger
        
        //Create Map for new updated Records - REQUIRED FOR TESTING!
        Map <ID, Opportunity> newOppMap = new Map <ID, Opportunity>(updatedTestOpps); 
        
        OppTriggerHelper.updateSharingOppFiles(newOppMap,oldOppMap); //This will provide test coverage for Apex Class method
    
        
        //End Testing
        System.Test.stopTest();
        
        //Evaluate Testing Results
        
        //Queries all related file Links associated with test Opp Records
        List <ContentDocumentLink> relatedTestFiles = [SELECT ContentDocumentId, LinkedEntityId, ShareType, Visibility 
                                               	   	   FROM ContentDocumentLink 
                                                       WHERE LinkedEntityId IN :newOppMap.keyset() AND Visibility != 'AllUsers']; 
        
        //In the SOQL above, I filtered file links on those that had Visibility not equal to 'AllUsers'
        //However, if the test code changed the visibility of all those file links from 'InternalUsers' to 'AllUsers' 
        //Then, this SOQL should have 0 records within it. Thus, this ensures that testing was a success!
        System.assertEquals(true, relatedTestFiles.size() == 0);
           
    }
    
}