Hi all, I'm new to salesforce development. I'm trying to write test class for Registartion handler class and it didn't give me full coverage even after multiple changes.

Apex class:

global class RegistrationHandlerSSO implements Auth.RegistrationHandler {

    global User createUser(Id portalId, Auth.UserData data) {

        //Querying all users
        List<User> userList = new List<User>([
            SELECT  Id
            FROM    User
            WHERE   Id =: data.attributeMap.get('alt_username') AND
                    IsActive = true and
                    SFDC_License_Type__c = 'Customer Community Plus Login'
        ]);

        User uId;
        boolean generateUser = true;

        for (User u:userList) {

            //Checking that current user is already there in system or not.
            //If yes, performing below operations
            if (u.Id == data.attributeMap.get('alt_username')) {

                Id userIds= u.Id;

                //Fetch ThirdPartyAccountLink records associated with this user and delete it using
                // Auth.AuthToken.revokeAccess() method
                List<ThirdPartyAccountLink> thirdPartyActLink = new List<ThirdPartyAccountLink>(
                    [SELECT Handle, Provider, SsoProviderName, UserId, ThirdPartyAccountLinkKey,
                            user.contact.Account.Id, remoteIdentifier, SsoProvider.id
                     FROM   ThirdPartyAccountLink
                     WHERE  UserId =: userIds
                     LIMIT  1]);

                if(!thirdPartyActLink.isEmpty())
                Auth.AuthToken.revokeAccess(
                            thirdPartyActLink[0].SsoProvider.id,
                            thirdPartyActLink[0].Provider,
                            thirdPartyActLink[0].UserId,
                            thirdPartyActLink[0].remoteIdentifier
                        );

                //Marking this boolean as false to avoid creating new user
                generateUser = false;

                //if user is aleadythere in system paas it to updateUser() method to avoid linking
                // Id change
                updateUser(u.Id, portalId, data);
                uId = u;
            }
        }

        return(uId);
    }

    global void updateUser(Id userId, Id portalId, Auth.UserData data) {

        // checking for ID whether it same as logged in community user. if not then update it
        if(userId != data.attributeMap.get('alt_username')) {
            userId = data.attributeMap.get('alt_username');
        }

        List<User> userList = new List<User>([
            SELECT  Id
            FROM    User
            WHERE   Id =: userId
        ]);

        for (User u:userList) {

            List<ThirdPartyAccountLink> thirdPartyActLink = new List<ThirdPartyAccountLink>(
                    [SELECT Handle, Provider, SsoProviderName, UserId, ThirdPartyAccountLinkKey,
                            user.contact.Account.Id, remoteIdentifier, SsoProvider.id
                     FROM   ThirdPartyAccountLink
                     WHERE  UserId =: u.Id
                     LIMIT  1]);

                if(!thirdPartyActLink.isEmpty()) {
                    try {
                        Auth.AuthToken.revokeAccess(
                            thirdPartyActLink[0].SsoProvider.id,
                            thirdPartyActLink[0].Provider,
                            thirdPartyActLink[0].UserId,
                            thirdPartyActLink[0].remoteIdentifier
                        );
                    } catch (System.DmlException e) {
                        System.debug('@@@Error while deleteImmediate::'+e);
                        System.Debug('Cause: ' + e.getCause());
                        System.Debug('TypeName: ' + e.getTypeName());
                        System.Debug('getDmlFieldNames: ' + e.getDmlFieldNames(0));
                        System.Debug('getDmlFields: ' + e.getDmlFields(0));
                        System.Debug('getDmlId: ' + e.getDmlId(0));
                        System.Debug('getDmlMessage: ' + e.getDmlMessage(0));
                        System.Debug('getDmlType: ' + e.getDmlType(0));
                        System.Debug('getNumDml: ' + e.getNumDml());
                        System.Debug('Message: ' + e.getMessage());
                    }
                }

                User u2 = new User(id=u.Id);
                update(u2);
        }
    }
}

@isTest
private class RegistrationHandlerSSOTest {
    static testMethod void testCreateUser() {

        Profile pf= [Select Id from profile where Name='System Administrator'];

        RegistrationHandlerSSO handler = new RegistrationHandlerSSO();

        Auth.UserData userData = new Auth.UserData (
                                                   'testId', 'testFirst', 'testLast',
                                                   'testFirst testLast', 'testuse8888r@example.org',
                                                   null, 'testuse8888r@example.org', 'en_US',
                                                   'facebook', null,
                                                   new Map<String, String>{'language' => 'en_US'}
                                                   );
        User u1 = new User (
            				firstname = 'testFirst',
                            lastName = 'testLast',
                            email = 'testuse8888r@example.org',
                            Username = 'testuse8888r@example.org',
                            EmailEncodingKey = 'ISO-8859-1',
                            Alias = 'teste8r',
                            TimeZoneSidKey = 'America/Los_Angeles',
                            LocaleSidKey = 'en_US',
                            LanguageLocaleKey = 'en_US',
                            ProfileId = pf.Id
                            );
        insert u1;

        try {
            User u = handler.createUser(null, userData);
		}
        catch(Exception e) {
            System.debug('Error: '+e);
        }
    }
    
    static testMethod void testUpdateUser() {

        Profile pf= [Select Id from profile where Name='System Administrator'];

        User u1 = new User (
                            firstname = 'testFirst',
                            lastName = 'testLast',
                            email = 'testuse8888r@example.org',
                            Username = 'testuse8888r@example.org',
                            EmailEncodingKey = 'ISO-8859-1',
                            Alias = 'teste8r',
                            TimeZoneSidKey = 'America/Los_Angeles',
                            LocaleSidKey = 'en_US',
                            LanguageLocaleKey = 'en_US',
                            ProfileId = pf.Id
                            );
        insert u1;

        RegistrationHandlerSSO handler = new RegistrationHandlerSSO();

        Auth.UserData userData = new Auth.UserData (
                                                   'testId', 'testFirst', 'testLast',
                                                   'testFirst testLast', 'testuse8888r@example.org',
                                                   null, 'testuse8888r@example.org', 'en_US',
                                                   'facebook', null,
                                                   new Map<String, String>{'language' => 'en_US'}
                                                   );

        try {
            UserData = new Auth.UserData (
                                         'testNewId', 'testNewFirst', 'testNewLast',
                                         'testNewFirst testNewLast', 'testnewuser@example.org',
                                         null, 'testnewuserlong', 'en_US', 'facebook',
                                         null, new Map<String, String>{}
                                         );
            handler.updateUser(u1.Id, null, userData);
        }
        catch(Exception e) {
            System.debug('Error: '+e);
        }
    }
}