global class AssignmentToContact implements Database.Batchable<sObject> {
    
    //Start method implementation for batchable interface
    global Database.queryLocator start(Database.BatchableContext bc){
       
        String query = 'SELECT Id, Contact__c FROM pse__Assignment__c WHERE pse__End_Date__c >= TODAY AND pse__Is_Billable__c = TRUE';
        return Database.getQueryLocator(query);
    }

    //execute method implementation for batchable interface
    global void execute (Database.BatchableContext bc, List<pse__Assignment__c> assignmentList){

        Map<Id,Id> contactAssignmentMap = new Map<Id,Id>();
        List<Contact> updateContactList = new List<Contact>();

        //assignmentList will only have records that passed the criteria in line no 11
        for(pse__Assignment__c assign : assignmentList){
            //preparing a map with contact ID and associated assginment
            contactAssignmentMap.put(assign.pse__Resource__c,assign.Id);
        


        //fetching the contact records based on the ID to update the assigment field.
        for(Contact con : [Select Id, Assignment__c from Contact where Id IN: contactAssignmentMap.keySet()])
            if(contactAssignmentMap.containsKey(con.Id)){
                con.Assignment__c = contactAssignmentMap.get(assign.Id);
            
            updateContactList.add(con);
        }

        if(updateContactList != null && updateContactList.size() > 0)
            UPDATE updateContactList;
    }

    //finish method implementation for batchable interface
    global void finish (Database.BatchableContext bc);

    }
}

@isTest
private class AssignmentToContactTest {
    static testmethod void testAssignmentToContactScheduledJob(){
        
        //create a contact record 
        //create an assignment where the contact is = to the contact we just created 
        //make sure the assignment__c field is NULL 
        //make sure the assignment end date is greater that today and is billable        
           
        disableTriggerHandlers();
                
        //create a contact record 
        TestDataFactory.initContacts();
        
        //create an assignment where the contact is = to the contact we just created 
        //make sure the assignment__c field is NULL 
        //make sure the assignment end date is greater that today and is billable 
        
        TestDataFactory.initAssignments();

        // Make the needed updates to the assignment (lines 19,20,21)
        	TestDataFactory.assignments[0].pse__Resource__c = TestDataFactory.contacts[0].Id;
        	TestDataFactory.assignments[0].pse__Is_Billable__c = TRUE;
      
    	}
    
     	// Schedule the test 
        
        String jobId = System.schedule('testBasicScheduledApex',
        AssignmentToContact.CRON_EXP, 
          new AssignmentToContact());
        
        // Get the information from the CronTrigger API object
        CronTrigger ct = [SELECT Id, CronExpression, TimesTriggered, NextFireTime
         				  FROM CronTrigger WHERE id = :jobId];
        
        // Verify the expressions are the same
        System.assertEquals(AssignmentToContact.CRON_EXP, ct.CronExpression);
        
        // Verify the job has not run
        System.assertEquals(0, ct.TimesTriggered);
        
        // Verify the next time the job will run
        System.assertEquals('2019-07-12 00:00:00', String.valueOf(ct.NextFireTime));
        System.assertNotEquals(false,
                               [SELECT Id FROM pse__Assignment__c WHERE id = :TestDataFactory.assignments[0].id]);
        
        
        List<Contact> ContactList = [SELECT id FROM Contact WHERE assignment__c = NULL];
        update ContactList;
        Test.stopTest();
    




	/************************************************************************************************************
    // Name         disableTriggerHandlers
    // Description  Disables non-critical custom triggers to reduce load on governor limits and increase 
    //              test performance
    *************************************************************************************************************/
    private static void disableTriggerHandlers()
    {
        TriggerHandlerBase.disableAllTriggerHandlers(Account.sObjectType);
        TriggerHandlerBase.disableAllTriggerHandlers(Contact.sObjectType);
        TriggerHandlerBase.disableAllTriggerHandlers(pse__Region__c.sObjectType);
        TriggerHandlerBase.disableAllTriggerHandlers(pse__Practice__c.sObjectType);
        TriggerHandlerBase.disableAllTriggerHandlers(pse__Grp__c.sObjectType);
        TriggerHandlerBase.disableAllTriggerHandlers(pse__Proj__c.sObjectType);
    }

}