Hello,

I have some problems in a testMethod when using 2 runAs(a User) with a User field modification between them.

Simplified example:

User u = new User(alias = 'test', email='testUser_1@test.com',
            emailencodingkey='UTF-8', lastname='Testing', languagelocalekey='fr',
            localesidkey='fr_FR_EURO', profileid = 'xxxx',
            timezonesidkey='Europe/Paris', UserName='testUser_1@test.com');

System.runAs(u){
	System.assertEquals(Userinfo.getUserName(),'testUser_1@test.com');		//No problem here
}

u.UserName='testUser_2@test.com';		//I change the username

System.runAs(u){
	System.assertEquals(u.UserName,'testUser_2@test.com');				//No problem
	System.assertEquals(Userinfo.getUserName(),'testUser_2@test.com');		//Problem: Expected: testUser_1@test.com, Actual: testUser_2@test.com
}

And I have no problem if I omit the first runAs:

User u = new User(alias = 'test', email='testUser_1@test.com',
            emailencodingkey='UTF-8', lastname='Testing', languagelocalekey='fr',
            localesidkey='fr_FR_EURO', profileid = 'xxxx',
            timezonesidkey='Europe/Paris', UserName='testUser_1@test.com');


u.UserName='testUser_2@test.com';		//I change the username

System.runAs(u){
	System.assertEquals(u.UserName,'testUser_2@test.com');				//No problem
	System.assertEquals(Userinfo.getUserName(),'testUser_2@test.com');		//No problem
}

Is that a bug from Apex?

Does someone has a solution to fix this problem? (other than creating another User object between the 2 runAs)

Thanks