[SalesForce] Mixed DML operation error on User Trigger breaking test classes

I have a user trigger that upserts both setup objects and custom settings records for provisioning purposes, and have everything in @future methods to avoid mixed DML operation errors. All of our test classes are breaking however, as almost all of them insert users. Does anyone have a workaround for this, besides doing something like adding System.runAs to all other test classes?

Best Answer

Gonna go on a hunch here.

I learned the hard way that Mixed object DML is a powerful, but quirky tool. One of the things I learned is that it acts like the list is split into lists by adjacent type. In other words, if your List contains elements of User, Account and Opportunity (U, A and O respectively) like this:

UAAAUUOOOUAUO

That list will be "broken" into 8 sub lists by the DML call like this:

U
AAA
UU
OOO
U
A
U
O

This can quickly hit the "max chunks" limit.

Thankfully, a quick list.sort(); call will result in a mix-dml list like this UUUUUAAAAOOOO, which is broken into only 3 "chunks".

Try sorting your list before insert/update/etc. See if that Helps?

Related Solutions

[SalesForce] How to Get Mixed DML in a Unit Test

I got a mixed dml exception with the following code.

@isTest
public class testTester {
    public static testmethod void testMixedDml() {

        Profile p = [select id from profile where name='Standard User'];

        User u = new User(alias = 'standt', email='standarduser@testorg.com', 
                emailencodingkey='UTF-8', lastname='Testing', 
                languagelocalekey='en_US', 
                localesidkey='en_US', profileid = p.Id,
                timezonesidkey='America/Los_Angeles', 
                username='standarduser3234234@testorg.com');
        insert u;


        Group g = new Group();
        g.Name = 'Test Group';
        g.DeveloperName = 'TestGroup';
        insert g;

        GroupMember gm = new GroupMember();
        gm.GroupId = g.Id;
        gm.UserOrGroupId = u.Id;
        insert gm;


        Account a = new Account();
        a.Name = 'Test Account';
        insert a;
    }
}

[SalesForce] Retrieving records from @testSetup Method

The compilation problem is that the definition of u is local to one method and you are trying to reference it in a another method. You can get a local reference to that user to avoid the compilation error like this:

static testMethod void testOppsPt1(){
    User u = [select Id from User where Username = 'astest@wexeurope.com'];
    List<Opportunity> immOpportunitys = new List<Opportunity>();
    for (Integer i = 0; i < 1; i++) {
        ...
}

This keeps all the data creation in the @TestSetup method that is run once only irrespective of how many test methods there are.

Note that by design all static variables are cleared before each test method is executed; querying isthe recommended approach.

Best Answer

Related Solutions

[SalesForce] How to Get Mixed DML in a Unit Test

[SalesForce] Retrieving records from @testSetup Method

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