@isTest
private class AgentWorkTriggerTest{
//by using @testSetup we can create the test data once and use it in multiple tests

    @testSetup static void setup() {
                //DateTime dt = datetime.now();

        Case c = new Case(Status='New');
        //add other fields as required by validation
                insert c;
    
        AgentWork aw = new AgentWork();
                //aw.AcceptDatetime = null;
                insert aw;
    }
//do a test to see if the code does what it should
    @isTest static void test_update_positive(){
        Agentwork aw = [SELECT id, AcceptDateTime FROM AgentWork LIMIT 1];
        DateTime dt = datetime.now();
        //aw.AcceptDatetime = datetime.now();
        update aw;
        Case c = [SELECT Id, Status FROM Case LIMIT 1];
        System.assertEquals('In Progress',c.Status);
        System.assertEquals(dt,aw.AcceptDateTime);
        
    }

//should also run a negative test - does the test only run when we update the date field
    @isTest static void test_update_negative(){
        Agentwork aw = [SELECT id, AcceptDateTime FROM AgentWork LIMIT 1];
        DateTime dt = datetime.now();
        //aw.someotherfield = somevaluetoudpate;
        update aw;
        Case c = [SELECT Id, Status FROM Case LIMIT 1];
        System.assertEquals('New',c.Status);
        System.assertEquals(null,aw.AcceptDateTime);
    }
}