How to change the UserInfo.getDefaultCurrency value in a test?

Question

I am trying to test some code that uses UserInfo.getDefaultCurrency() but can't figure out how to control that value in a test.

For example this doesn't work:

    User u = new User(Id = UserInfo.getUserId(), LocaleSidKey = 'fr_FR');
    update u;
    System.runAs(u) {
        // Changes the thousand separator but not the UserInfo.getDefaultCurrency()
    }

Is there a way to change this in a test?

(In the Setup UI there is a "Currency Locale" field on the "Organization Detail".)

Answer 1

This question is a bit older, but I just ran into the same issue myself.

Maybe in June 2017 it was correct, what Keith C wrote, but today - API version 43 - the DefaultCurrencyIsoCode is writable in a multicurrency org.

However, in a single currency org the field does not exist, and currencies can only be changed org-wide.

@isTest
public class CurrencyTest {
    @isTest
    public static void testDefaultCurrenciesOnUsers() {
        Set<String> objectFields = Schema.SObjectType.User.fields.getMap().keySet();

        // This is for Multicurrency orgs
        if(objectFields.contains('DefaultCurrencyIsoCode')) {
            User u = new User(LastName = 'Tester1');
            u.put('DefaultCurrencyIsoCode', 'USD');
            insert u;
            System.runAs(u) {
                System.assertEquals('USD', UserInfo.getDefaultCurrency());
            }
            u = new User(LastName = 'Tester2');
            u.put('DefaultCurrencyIsoCode', 'EUR');
            insert u;
            System.runAs(u) {
                System.assertEquals('EUR', UserInfo.getDefaultCurrency());
            }
        }   
        else {
            System.assert(false, 'You are not in a multi-currency org.');
        }
    }
}