Hello,

I'm having an issue with an Opportunity trigger that I'm writing, the trigger will change a User lookup field called ResponsibleParty to someone on the Opportunity Team when the stage changes. This trigger does work in the dev org, but I can't get it to work with a test class. Below is the Trigger and test class, it is failing when I perform the SOQL query on OpportunityTeamMember, it will return zero rows. Also I can take the test class code and put it right into the execute Annonymous Code windows and it all works.

FYI I'm fairly new to APEX and I'm working on the Bulkifing. 

Trigger -----

trigger Responsible_Party_Change on Opportunity (after update) {
    for (Opportunity opp : Trigger.new) {

        Opportunity oldOpp = Trigger.oldMap.get(opp.Id);
        //Getting the UserID for Opp Team Member with "Partner" Role
        OpportunityTeamMember partner = [SELECT UserId
                            FROM OpportunityTeamMember
                            WHERE OpportunityId = :opp.Id
                            AND TeamMemberRole = 'Partner'
                            LIMIT 1];

       //Getting the UserID for Opp Team Member with "Setup" Role
        OpportunityTeamMember setup = [SELECT UserId
                            FROM OpportunityTeamMember
                            WHERE OpportunityId = :opp.Id
                            AND TeamMemberRole = 'Setup'
                            LIMIT 1];

        //Getting the UserID for Opp Team Member with "Processor" Role
        OpportunityTeamMember processor = [SELECT UserId
                            FROM OpportunityTeamMember
                            WHERE OpportunityId = :opp.Id
                            AND TeamMemberRole = 'Processor'
                            LIMIT 1];

        //IF the Stage is Partner then set Responsible Party to Partner
        if (!oldOpp.StageName.equals('Partner') && opp.StageName.equals('Partner'))
        {
                opp.Responsible_Party__c = partner.UserId;
        }
}

}

Test Class -----

@isTest
private class ResponsiblePartyChangeTest {
    
    @isTest static void StageChangeTest() {
        Opportunity opp = new Opportunity();
        opp.CloseDate = Date.Today();
        opp.OwnerId = UserInfo.getUserId();
        opp.Name = 'Test Opp';
        opp.StageName = 'Officer';
        Insert(opp);

        opp.StageName = 'Partner';
        Update(opp);
    }
    
}


Any help would be greatly Appreciated!!